1 // SPDX-License-Identifier: GPL-2.0-only 1 // SPDX-License-Identifier: GPL-2.0-only
2 /* 2 /*
3 * linux/fs/exec.c 3 * linux/fs/exec.c
4 * 4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds 5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */ 6 */
7 7
8 /* 8 /*
9 * #!-checking implemented by tytso. 9 * #!-checking implemented by tytso.
10 */ 10 */
11 /* 11 /*
12 * Demand-loading implemented 01.12.91 - no ne 12 * Demand-loading implemented 01.12.91 - no need to read anything but
13 * the header into memory. The inode of the ex 13 * the header into memory. The inode of the executable is put into
14 * "current->executable", and page faults do t 14 * "current->executable", and page faults do the actual loading. Clean.
15 * 15 *
16 * Once more I can proudly say that linux stoo 16 * Once more I can proudly say that linux stood up to being changed: it
17 * was less than 2 hours work to get demand-lo 17 * was less than 2 hours work to get demand-loading completely implemented.
18 * 18 *
19 * Demand loading changed July 1993 by Eric Yo 19 * Demand loading changed July 1993 by Eric Youngdale. Use mmap instead,
20 * current->executable is only used by the pro 20 * current->executable is only used by the procfs. This allows a dispatch
21 * table to check for several different types 21 * table to check for several different types of binary formats. We keep
22 * trying until we recognize the file or we ru 22 * trying until we recognize the file or we run out of supported binary
23 * formats. 23 * formats.
24 */ 24 */
25 25
26 #include <linux/kernel_read_file.h> 26 #include <linux/kernel_read_file.h>
27 #include <linux/slab.h> 27 #include <linux/slab.h>
28 #include <linux/file.h> 28 #include <linux/file.h>
29 #include <linux/fdtable.h> 29 #include <linux/fdtable.h>
30 #include <linux/mm.h> 30 #include <linux/mm.h>
31 #include <linux/stat.h> 31 #include <linux/stat.h>
32 #include <linux/fcntl.h> 32 #include <linux/fcntl.h>
33 #include <linux/swap.h> 33 #include <linux/swap.h>
34 #include <linux/string.h> 34 #include <linux/string.h>
35 #include <linux/init.h> 35 #include <linux/init.h>
36 #include <linux/sched/mm.h> 36 #include <linux/sched/mm.h>
37 #include <linux/sched/coredump.h> 37 #include <linux/sched/coredump.h>
38 #include <linux/sched/signal.h> 38 #include <linux/sched/signal.h>
39 #include <linux/sched/numa_balancing.h> 39 #include <linux/sched/numa_balancing.h>
40 #include <linux/sched/task.h> 40 #include <linux/sched/task.h>
41 #include <linux/pagemap.h> 41 #include <linux/pagemap.h>
42 #include <linux/perf_event.h> 42 #include <linux/perf_event.h>
43 #include <linux/highmem.h> 43 #include <linux/highmem.h>
44 #include <linux/spinlock.h> 44 #include <linux/spinlock.h>
45 #include <linux/key.h> 45 #include <linux/key.h>
46 #include <linux/personality.h> 46 #include <linux/personality.h>
47 #include <linux/binfmts.h> 47 #include <linux/binfmts.h>
48 #include <linux/utsname.h> 48 #include <linux/utsname.h>
49 #include <linux/pid_namespace.h> 49 #include <linux/pid_namespace.h>
50 #include <linux/module.h> 50 #include <linux/module.h>
51 #include <linux/namei.h> 51 #include <linux/namei.h>
52 #include <linux/mount.h> 52 #include <linux/mount.h>
53 #include <linux/security.h> 53 #include <linux/security.h>
54 #include <linux/syscalls.h> 54 #include <linux/syscalls.h>
55 #include <linux/tsacct_kern.h> 55 #include <linux/tsacct_kern.h>
56 #include <linux/cn_proc.h> 56 #include <linux/cn_proc.h>
57 #include <linux/audit.h> 57 #include <linux/audit.h>
58 #include <linux/kmod.h> 58 #include <linux/kmod.h>
59 #include <linux/fsnotify.h> 59 #include <linux/fsnotify.h>
60 #include <linux/fs_struct.h> 60 #include <linux/fs_struct.h>
61 #include <linux/oom.h> 61 #include <linux/oom.h>
62 #include <linux/compat.h> 62 #include <linux/compat.h>
63 #include <linux/vmalloc.h> 63 #include <linux/vmalloc.h>
64 #include <linux/io_uring.h> 64 #include <linux/io_uring.h>
65 #include <linux/syscall_user_dispatch.h> 65 #include <linux/syscall_user_dispatch.h>
66 #include <linux/coredump.h> 66 #include <linux/coredump.h>
67 #include <linux/time_namespace.h> 67 #include <linux/time_namespace.h>
68 #include <linux/user_events.h> 68 #include <linux/user_events.h>
69 #include <linux/rseq.h> 69 #include <linux/rseq.h>
70 #include <linux/ksm.h> 70 #include <linux/ksm.h>
71 71
72 #include <linux/uaccess.h> 72 #include <linux/uaccess.h>
73 #include <asm/mmu_context.h> 73 #include <asm/mmu_context.h>
74 #include <asm/tlb.h> 74 #include <asm/tlb.h>
75 75
76 #include <trace/events/task.h> 76 #include <trace/events/task.h>
77 #include "internal.h" 77 #include "internal.h"
78 78
79 #include <trace/events/sched.h> 79 #include <trace/events/sched.h>
80 80
81 static int bprm_creds_from_file(struct linux_b 81 static int bprm_creds_from_file(struct linux_binprm *bprm);
82 82
83 int suid_dumpable = 0; 83 int suid_dumpable = 0;
84 84
85 static LIST_HEAD(formats); 85 static LIST_HEAD(formats);
86 static DEFINE_RWLOCK(binfmt_lock); 86 static DEFINE_RWLOCK(binfmt_lock);
87 87
88 void __register_binfmt(struct linux_binfmt * f 88 void __register_binfmt(struct linux_binfmt * fmt, int insert)
89 { 89 {
90 write_lock(&binfmt_lock); 90 write_lock(&binfmt_lock);
91 insert ? list_add(&fmt->lh, &formats) 91 insert ? list_add(&fmt->lh, &formats) :
92 list_add_tail(&fmt->lh, &form 92 list_add_tail(&fmt->lh, &formats);
93 write_unlock(&binfmt_lock); 93 write_unlock(&binfmt_lock);
94 } 94 }
95 95
96 EXPORT_SYMBOL(__register_binfmt); 96 EXPORT_SYMBOL(__register_binfmt);
97 97
98 void unregister_binfmt(struct linux_binfmt * f 98 void unregister_binfmt(struct linux_binfmt * fmt)
99 { 99 {
100 write_lock(&binfmt_lock); 100 write_lock(&binfmt_lock);
101 list_del(&fmt->lh); 101 list_del(&fmt->lh);
102 write_unlock(&binfmt_lock); 102 write_unlock(&binfmt_lock);
103 } 103 }
104 104
105 EXPORT_SYMBOL(unregister_binfmt); 105 EXPORT_SYMBOL(unregister_binfmt);
106 106
107 static inline void put_binfmt(struct linux_bin 107 static inline void put_binfmt(struct linux_binfmt * fmt)
108 { 108 {
109 module_put(fmt->module); 109 module_put(fmt->module);
110 } 110 }
111 111
112 bool path_noexec(const struct path *path) 112 bool path_noexec(const struct path *path)
113 { 113 {
114 return (path->mnt->mnt_flags & MNT_NOE 114 return (path->mnt->mnt_flags & MNT_NOEXEC) ||
115 (path->mnt->mnt_sb->s_iflags & 115 (path->mnt->mnt_sb->s_iflags & SB_I_NOEXEC);
116 } 116 }
117 117
118 #ifdef CONFIG_USELIB 118 #ifdef CONFIG_USELIB
119 /* 119 /*
120 * Note that a shared library must be both rea 120 * Note that a shared library must be both readable and executable due to
121 * security reasons. 121 * security reasons.
122 * 122 *
123 * Also note that we take the address to load 123 * Also note that we take the address to load from the file itself.
124 */ 124 */
125 SYSCALL_DEFINE1(uselib, const char __user *, l 125 SYSCALL_DEFINE1(uselib, const char __user *, library)
126 { 126 {
127 struct linux_binfmt *fmt; 127 struct linux_binfmt *fmt;
128 struct file *file; 128 struct file *file;
129 struct filename *tmp = getname(library 129 struct filename *tmp = getname(library);
130 int error = PTR_ERR(tmp); 130 int error = PTR_ERR(tmp);
131 static const struct open_flags uselib_ 131 static const struct open_flags uselib_flags = {
132 .open_flag = O_LARGEFILE | O_R 132 .open_flag = O_LARGEFILE | O_RDONLY,
133 .acc_mode = MAY_READ | MAY_EXE 133 .acc_mode = MAY_READ | MAY_EXEC,
134 .intent = LOOKUP_OPEN, 134 .intent = LOOKUP_OPEN,
135 .lookup_flags = LOOKUP_FOLLOW, 135 .lookup_flags = LOOKUP_FOLLOW,
136 }; 136 };
137 137
138 if (IS_ERR(tmp)) 138 if (IS_ERR(tmp))
139 goto out; 139 goto out;
140 140
141 file = do_filp_open(AT_FDCWD, tmp, &us 141 file = do_filp_open(AT_FDCWD, tmp, &uselib_flags);
142 putname(tmp); 142 putname(tmp);
143 error = PTR_ERR(file); 143 error = PTR_ERR(file);
144 if (IS_ERR(file)) 144 if (IS_ERR(file))
145 goto out; 145 goto out;
146 146
147 /* 147 /*
148 * Check do_open_execat() for an expla 148 * Check do_open_execat() for an explanation.
149 */ 149 */
150 error = -EACCES; 150 error = -EACCES;
151 if (WARN_ON_ONCE(!S_ISREG(file_inode(f 151 if (WARN_ON_ONCE(!S_ISREG(file_inode(file)->i_mode)) ||
152 path_noexec(&file->f_path)) 152 path_noexec(&file->f_path))
153 goto exit; 153 goto exit;
154 154
155 error = -ENOEXEC; 155 error = -ENOEXEC;
156 156
157 read_lock(&binfmt_lock); 157 read_lock(&binfmt_lock);
158 list_for_each_entry(fmt, &formats, lh) 158 list_for_each_entry(fmt, &formats, lh) {
159 if (!fmt->load_shlib) 159 if (!fmt->load_shlib)
160 continue; 160 continue;
161 if (!try_module_get(fmt->modul 161 if (!try_module_get(fmt->module))
162 continue; 162 continue;
163 read_unlock(&binfmt_lock); 163 read_unlock(&binfmt_lock);
164 error = fmt->load_shlib(file); 164 error = fmt->load_shlib(file);
165 read_lock(&binfmt_lock); 165 read_lock(&binfmt_lock);
166 put_binfmt(fmt); 166 put_binfmt(fmt);
167 if (error != -ENOEXEC) 167 if (error != -ENOEXEC)
168 break; 168 break;
169 } 169 }
170 read_unlock(&binfmt_lock); 170 read_unlock(&binfmt_lock);
171 exit: 171 exit:
172 fput(file); 172 fput(file);
173 out: 173 out:
174 return error; 174 return error;
175 } 175 }
176 #endif /* #ifdef CONFIG_USELIB */ 176 #endif /* #ifdef CONFIG_USELIB */
177 177
178 #ifdef CONFIG_MMU 178 #ifdef CONFIG_MMU
179 /* 179 /*
180 * The nascent bprm->mm is not visible until e 180 * The nascent bprm->mm is not visible until exec_mmap() but it can
181 * use a lot of memory, account these pages in 181 * use a lot of memory, account these pages in current->mm temporary
182 * for oom_badness()->get_mm_rss(). Once exec 182 * for oom_badness()->get_mm_rss(). Once exec succeeds or fails, we
183 * change the counter back via acct_arg_size(0 183 * change the counter back via acct_arg_size(0).
184 */ 184 */
185 static void acct_arg_size(struct linux_binprm 185 static void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
186 { 186 {
187 struct mm_struct *mm = current->mm; 187 struct mm_struct *mm = current->mm;
188 long diff = (long)(pages - bprm->vma_p 188 long diff = (long)(pages - bprm->vma_pages);
189 189
190 if (!mm || !diff) 190 if (!mm || !diff)
191 return; 191 return;
192 192
193 bprm->vma_pages = pages; 193 bprm->vma_pages = pages;
194 add_mm_counter(mm, MM_ANONPAGES, diff) 194 add_mm_counter(mm, MM_ANONPAGES, diff);
195 } 195 }
196 196
197 static struct page *get_arg_page(struct linux_ 197 static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
198 int write) 198 int write)
199 { 199 {
200 struct page *page; 200 struct page *page;
201 struct vm_area_struct *vma = bprm->vma 201 struct vm_area_struct *vma = bprm->vma;
202 struct mm_struct *mm = bprm->mm; 202 struct mm_struct *mm = bprm->mm;
203 int ret; 203 int ret;
204 204
205 /* 205 /*
206 * Avoid relying on expanding the stac 206 * Avoid relying on expanding the stack down in GUP (which
207 * does not work for STACK_GROWSUP any 207 * does not work for STACK_GROWSUP anyway), and just do it
208 * by hand ahead of time. 208 * by hand ahead of time.
209 */ 209 */
210 if (write && pos < vma->vm_start) { 210 if (write && pos < vma->vm_start) {
211 mmap_write_lock(mm); 211 mmap_write_lock(mm);
212 ret = expand_downwards(vma, po 212 ret = expand_downwards(vma, pos);
213 if (unlikely(ret < 0)) { 213 if (unlikely(ret < 0)) {
214 mmap_write_unlock(mm); 214 mmap_write_unlock(mm);
215 return NULL; 215 return NULL;
216 } 216 }
217 mmap_write_downgrade(mm); 217 mmap_write_downgrade(mm);
218 } else 218 } else
219 mmap_read_lock(mm); 219 mmap_read_lock(mm);
220 220
221 /* 221 /*
222 * We are doing an exec(). 'current' 222 * We are doing an exec(). 'current' is the process
223 * doing the exec and 'mm' is the new 223 * doing the exec and 'mm' is the new process's mm.
224 */ 224 */
225 ret = get_user_pages_remote(mm, pos, 1 225 ret = get_user_pages_remote(mm, pos, 1,
226 write ? FOLL_WRITE : 0 226 write ? FOLL_WRITE : 0,
227 &page, NULL); 227 &page, NULL);
228 mmap_read_unlock(mm); 228 mmap_read_unlock(mm);
229 if (ret <= 0) 229 if (ret <= 0)
230 return NULL; 230 return NULL;
231 231
232 if (write) 232 if (write)
233 acct_arg_size(bprm, vma_pages( 233 acct_arg_size(bprm, vma_pages(vma));
234 234
235 return page; 235 return page;
236 } 236 }
237 237
238 static void put_arg_page(struct page *page) 238 static void put_arg_page(struct page *page)
239 { 239 {
240 put_page(page); 240 put_page(page);
241 } 241 }
242 242
243 static void free_arg_pages(struct linux_binprm 243 static void free_arg_pages(struct linux_binprm *bprm)
244 { 244 {
245 } 245 }
246 246
247 static void flush_arg_page(struct linux_binprm 247 static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,
248 struct page *page) 248 struct page *page)
249 { 249 {
250 flush_cache_page(bprm->vma, pos, page_ 250 flush_cache_page(bprm->vma, pos, page_to_pfn(page));
251 } 251 }
252 252
253 static int __bprm_mm_init(struct linux_binprm 253 static int __bprm_mm_init(struct linux_binprm *bprm)
254 { 254 {
255 int err; 255 int err;
256 struct vm_area_struct *vma = NULL; 256 struct vm_area_struct *vma = NULL;
257 struct mm_struct *mm = bprm->mm; 257 struct mm_struct *mm = bprm->mm;
258 258
259 bprm->vma = vma = vm_area_alloc(mm); 259 bprm->vma = vma = vm_area_alloc(mm);
260 if (!vma) 260 if (!vma)
261 return -ENOMEM; 261 return -ENOMEM;
262 vma_set_anonymous(vma); 262 vma_set_anonymous(vma);
263 263
264 if (mmap_write_lock_killable(mm)) { 264 if (mmap_write_lock_killable(mm)) {
265 err = -EINTR; 265 err = -EINTR;
266 goto err_free; 266 goto err_free;
267 } 267 }
268 268
269 /* 269 /*
270 * Need to be called with mmap write l 270 * Need to be called with mmap write lock
271 * held, to avoid race with ksmd. 271 * held, to avoid race with ksmd.
272 */ 272 */
273 err = ksm_execve(mm); 273 err = ksm_execve(mm);
274 if (err) 274 if (err)
275 goto err_ksm; 275 goto err_ksm;
276 276
277 /* 277 /*
278 * Place the stack at the largest stac 278 * Place the stack at the largest stack address the architecture
279 * supports. Later, we'll move this to 279 * supports. Later, we'll move this to an appropriate place. We don't
280 * use STACK_TOP because that can depe 280 * use STACK_TOP because that can depend on attributes which aren't
281 * configured yet. 281 * configured yet.
282 */ 282 */
283 BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK 283 BUILD_BUG_ON(VM_STACK_FLAGS & VM_STACK_INCOMPLETE_SETUP);
284 vma->vm_end = STACK_TOP_MAX; 284 vma->vm_end = STACK_TOP_MAX;
285 vma->vm_start = vma->vm_end - PAGE_SIZ 285 vma->vm_start = vma->vm_end - PAGE_SIZE;
286 vm_flags_init(vma, VM_SOFTDIRTY | VM_S 286 vm_flags_init(vma, VM_SOFTDIRTY | VM_STACK_FLAGS | VM_STACK_INCOMPLETE_SETUP);
287 vma->vm_page_prot = vm_get_page_prot(v 287 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
288 288
289 err = insert_vm_struct(mm, vma); 289 err = insert_vm_struct(mm, vma);
290 if (err) 290 if (err)
291 goto err; 291 goto err;
292 292
293 mm->stack_vm = mm->total_vm = 1; 293 mm->stack_vm = mm->total_vm = 1;
294 mmap_write_unlock(mm); 294 mmap_write_unlock(mm);
295 bprm->p = vma->vm_end - sizeof(void *) 295 bprm->p = vma->vm_end - sizeof(void *);
296 return 0; 296 return 0;
297 err: 297 err:
298 ksm_exit(mm); 298 ksm_exit(mm);
299 err_ksm: 299 err_ksm:
300 mmap_write_unlock(mm); 300 mmap_write_unlock(mm);
301 err_free: 301 err_free:
302 bprm->vma = NULL; 302 bprm->vma = NULL;
303 vm_area_free(vma); 303 vm_area_free(vma);
304 return err; 304 return err;
305 } 305 }
306 306
307 static bool valid_arg_len(struct linux_binprm 307 static bool valid_arg_len(struct linux_binprm *bprm, long len)
308 { 308 {
309 return len <= MAX_ARG_STRLEN; 309 return len <= MAX_ARG_STRLEN;
310 } 310 }
311 311
312 #else 312 #else
313 313
314 static inline void acct_arg_size(struct linux_ 314 static inline void acct_arg_size(struct linux_binprm *bprm, unsigned long pages)
315 { 315 {
316 } 316 }
317 317
318 static struct page *get_arg_page(struct linux_ 318 static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos,
319 int write) 319 int write)
320 { 320 {
321 struct page *page; 321 struct page *page;
322 322
323 page = bprm->page[pos / PAGE_SIZE]; 323 page = bprm->page[pos / PAGE_SIZE];
324 if (!page && write) { 324 if (!page && write) {
325 page = alloc_page(GFP_HIGHUSER 325 page = alloc_page(GFP_HIGHUSER|__GFP_ZERO);
326 if (!page) 326 if (!page)
327 return NULL; 327 return NULL;
328 bprm->page[pos / PAGE_SIZE] = 328 bprm->page[pos / PAGE_SIZE] = page;
329 } 329 }
330 330
331 return page; 331 return page;
332 } 332 }
333 333
334 static void put_arg_page(struct page *page) 334 static void put_arg_page(struct page *page)
335 { 335 {
336 } 336 }
337 337
338 static void free_arg_page(struct linux_binprm 338 static void free_arg_page(struct linux_binprm *bprm, int i)
339 { 339 {
340 if (bprm->page[i]) { 340 if (bprm->page[i]) {
341 __free_page(bprm->page[i]); 341 __free_page(bprm->page[i]);
342 bprm->page[i] = NULL; 342 bprm->page[i] = NULL;
343 } 343 }
344 } 344 }
345 345
346 static void free_arg_pages(struct linux_binprm 346 static void free_arg_pages(struct linux_binprm *bprm)
347 { 347 {
348 int i; 348 int i;
349 349
350 for (i = 0; i < MAX_ARG_PAGES; i++) 350 for (i = 0; i < MAX_ARG_PAGES; i++)
351 free_arg_page(bprm, i); 351 free_arg_page(bprm, i);
352 } 352 }
353 353
354 static void flush_arg_page(struct linux_binprm 354 static void flush_arg_page(struct linux_binprm *bprm, unsigned long pos,
355 struct page *page) 355 struct page *page)
356 { 356 {
357 } 357 }
358 358
359 static int __bprm_mm_init(struct linux_binprm 359 static int __bprm_mm_init(struct linux_binprm *bprm)
360 { 360 {
361 bprm->p = PAGE_SIZE * MAX_ARG_PAGES - 361 bprm->p = PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *);
362 return 0; 362 return 0;
363 } 363 }
364 364
365 static bool valid_arg_len(struct linux_binprm 365 static bool valid_arg_len(struct linux_binprm *bprm, long len)
366 { 366 {
367 return len <= bprm->p; 367 return len <= bprm->p;
368 } 368 }
369 369
370 #endif /* CONFIG_MMU */ 370 #endif /* CONFIG_MMU */
371 371
372 /* 372 /*
373 * Create a new mm_struct and populate it with 373 * Create a new mm_struct and populate it with a temporary stack
374 * vm_area_struct. We don't have enough conte 374 * vm_area_struct. We don't have enough context at this point to set the stack
375 * flags, permissions, and offset, so we use t 375 * flags, permissions, and offset, so we use temporary values. We'll update
376 * them later in setup_arg_pages(). 376 * them later in setup_arg_pages().
377 */ 377 */
378 static int bprm_mm_init(struct linux_binprm *b 378 static int bprm_mm_init(struct linux_binprm *bprm)
379 { 379 {
380 int err; 380 int err;
381 struct mm_struct *mm = NULL; 381 struct mm_struct *mm = NULL;
382 382
383 bprm->mm = mm = mm_alloc(); 383 bprm->mm = mm = mm_alloc();
384 err = -ENOMEM; 384 err = -ENOMEM;
385 if (!mm) 385 if (!mm)
386 goto err; 386 goto err;
387 387
388 /* Save current stack limit for all ca 388 /* Save current stack limit for all calculations made during exec. */
389 task_lock(current->group_leader); 389 task_lock(current->group_leader);
390 bprm->rlim_stack = current->signal->rl 390 bprm->rlim_stack = current->signal->rlim[RLIMIT_STACK];
391 task_unlock(current->group_leader); 391 task_unlock(current->group_leader);
392 392
393 err = __bprm_mm_init(bprm); 393 err = __bprm_mm_init(bprm);
394 if (err) 394 if (err)
395 goto err; 395 goto err;
396 396
397 return 0; 397 return 0;
398 398
399 err: 399 err:
400 if (mm) { 400 if (mm) {
401 bprm->mm = NULL; 401 bprm->mm = NULL;
402 mmdrop(mm); 402 mmdrop(mm);
403 } 403 }
404 404
405 return err; 405 return err;
406 } 406 }
407 407
408 struct user_arg_ptr { 408 struct user_arg_ptr {
409 #ifdef CONFIG_COMPAT 409 #ifdef CONFIG_COMPAT
410 bool is_compat; 410 bool is_compat;
411 #endif 411 #endif
412 union { 412 union {
413 const char __user *const __use 413 const char __user *const __user *native;
414 #ifdef CONFIG_COMPAT 414 #ifdef CONFIG_COMPAT
415 const compat_uptr_t __user *co 415 const compat_uptr_t __user *compat;
416 #endif 416 #endif
417 } ptr; 417 } ptr;
418 }; 418 };
419 419
420 static const char __user *get_user_arg_ptr(str 420 static const char __user *get_user_arg_ptr(struct user_arg_ptr argv, int nr)
421 { 421 {
422 const char __user *native; 422 const char __user *native;
423 423
424 #ifdef CONFIG_COMPAT 424 #ifdef CONFIG_COMPAT
425 if (unlikely(argv.is_compat)) { 425 if (unlikely(argv.is_compat)) {
426 compat_uptr_t compat; 426 compat_uptr_t compat;
427 427
428 if (get_user(compat, argv.ptr. 428 if (get_user(compat, argv.ptr.compat + nr))
429 return ERR_PTR(-EFAULT 429 return ERR_PTR(-EFAULT);
430 430
431 return compat_ptr(compat); 431 return compat_ptr(compat);
432 } 432 }
433 #endif 433 #endif
434 434
435 if (get_user(native, argv.ptr.native + 435 if (get_user(native, argv.ptr.native + nr))
436 return ERR_PTR(-EFAULT); 436 return ERR_PTR(-EFAULT);
437 437
438 return native; 438 return native;
439 } 439 }
440 440
441 /* 441 /*
442 * count() counts the number of strings in arr 442 * count() counts the number of strings in array ARGV.
443 */ 443 */
444 static int count(struct user_arg_ptr argv, int 444 static int count(struct user_arg_ptr argv, int max)
445 { 445 {
446 int i = 0; 446 int i = 0;
447 447
448 if (argv.ptr.native != NULL) { 448 if (argv.ptr.native != NULL) {
449 for (;;) { 449 for (;;) {
450 const char __user *p = 450 const char __user *p = get_user_arg_ptr(argv, i);
451 451
452 if (!p) 452 if (!p)
453 break; 453 break;
454 454
455 if (IS_ERR(p)) 455 if (IS_ERR(p))
456 return -EFAULT 456 return -EFAULT;
457 457
458 if (i >= max) 458 if (i >= max)
459 return -E2BIG; 459 return -E2BIG;
460 ++i; 460 ++i;
461 461
462 if (fatal_signal_pendi 462 if (fatal_signal_pending(current))
463 return -ERESTA 463 return -ERESTARTNOHAND;
464 cond_resched(); 464 cond_resched();
465 } 465 }
466 } 466 }
467 return i; 467 return i;
468 } 468 }
469 469
470 static int count_strings_kernel(const char *co 470 static int count_strings_kernel(const char *const *argv)
471 { 471 {
472 int i; 472 int i;
473 473
474 if (!argv) 474 if (!argv)
475 return 0; 475 return 0;
476 476
477 for (i = 0; argv[i]; ++i) { 477 for (i = 0; argv[i]; ++i) {
478 if (i >= MAX_ARG_STRINGS) 478 if (i >= MAX_ARG_STRINGS)
479 return -E2BIG; 479 return -E2BIG;
480 if (fatal_signal_pending(curre 480 if (fatal_signal_pending(current))
481 return -ERESTARTNOHAND 481 return -ERESTARTNOHAND;
482 cond_resched(); 482 cond_resched();
483 } 483 }
484 return i; 484 return i;
485 } 485 }
486 486
487 static inline int bprm_set_stack_limit(struct 487 static inline int bprm_set_stack_limit(struct linux_binprm *bprm,
488 unsigne 488 unsigned long limit)
489 { 489 {
490 #ifdef CONFIG_MMU 490 #ifdef CONFIG_MMU
491 /* Avoid a pathological bprm->p. */ 491 /* Avoid a pathological bprm->p. */
492 if (bprm->p < limit) 492 if (bprm->p < limit)
493 return -E2BIG; 493 return -E2BIG;
494 bprm->argmin = bprm->p - limit; 494 bprm->argmin = bprm->p - limit;
495 #endif 495 #endif
496 return 0; 496 return 0;
497 } 497 }
498 static inline bool bprm_hit_stack_limit(struct 498 static inline bool bprm_hit_stack_limit(struct linux_binprm *bprm)
499 { 499 {
500 #ifdef CONFIG_MMU 500 #ifdef CONFIG_MMU
501 return bprm->p < bprm->argmin; 501 return bprm->p < bprm->argmin;
502 #else 502 #else
503 return false; 503 return false;
504 #endif 504 #endif
505 } 505 }
506 506
507 /* 507 /*
508 * Calculate bprm->argmin from: 508 * Calculate bprm->argmin from:
509 * - _STK_LIM 509 * - _STK_LIM
510 * - ARG_MAX 510 * - ARG_MAX
511 * - bprm->rlim_stack.rlim_cur 511 * - bprm->rlim_stack.rlim_cur
512 * - bprm->argc 512 * - bprm->argc
513 * - bprm->envc 513 * - bprm->envc
514 * - bprm->p 514 * - bprm->p
515 */ 515 */
516 static int bprm_stack_limits(struct linux_binp 516 static int bprm_stack_limits(struct linux_binprm *bprm)
517 { 517 {
518 unsigned long limit, ptr_size; 518 unsigned long limit, ptr_size;
519 519
520 /* 520 /*
521 * Limit to 1/4 of the max stack size 521 * Limit to 1/4 of the max stack size or 3/4 of _STK_LIM
522 * (whichever is smaller) for the argv 522 * (whichever is smaller) for the argv+env strings.
523 * This ensures that: 523 * This ensures that:
524 * - the remaining binfmt code will n 524 * - the remaining binfmt code will not run out of stack space,
525 * - the program will have a reasonab 525 * - the program will have a reasonable amount of stack left
526 * to work from. 526 * to work from.
527 */ 527 */
528 limit = _STK_LIM / 4 * 3; 528 limit = _STK_LIM / 4 * 3;
529 limit = min(limit, bprm->rlim_stack.rl 529 limit = min(limit, bprm->rlim_stack.rlim_cur / 4);
530 /* 530 /*
531 * We've historically supported up to 531 * We've historically supported up to 32 pages (ARG_MAX)
532 * of argument strings even with small 532 * of argument strings even with small stacks
533 */ 533 */
534 limit = max_t(unsigned long, limit, AR 534 limit = max_t(unsigned long, limit, ARG_MAX);
535 /* Reject totally pathological counts. 535 /* Reject totally pathological counts. */
536 if (bprm->argc < 0 || bprm->envc < 0) 536 if (bprm->argc < 0 || bprm->envc < 0)
537 return -E2BIG; 537 return -E2BIG;
538 /* 538 /*
539 * We must account for the size of all 539 * We must account for the size of all the argv and envp pointers to
540 * the argv and envp strings, since th 540 * the argv and envp strings, since they will also take up space in
541 * the stack. They aren't stored until 541 * the stack. They aren't stored until much later when we can't
542 * signal to the parent that the child 542 * signal to the parent that the child has run out of stack space.
543 * Instead, calculate it here so it's 543 * Instead, calculate it here so it's possible to fail gracefully.
544 * 544 *
545 * In the case of argc = 0, make sure 545 * In the case of argc = 0, make sure there is space for adding a
546 * empty string (which will bump argc 546 * empty string (which will bump argc to 1), to ensure confused
547 * userspace programs don't start proc 547 * userspace programs don't start processing from argv[1], thinking
548 * argc can never be 0, to keep them f 548 * argc can never be 0, to keep them from walking envp by accident.
549 * See do_execveat_common(). 549 * See do_execveat_common().
550 */ 550 */
551 if (check_add_overflow(max(bprm->argc, 551 if (check_add_overflow(max(bprm->argc, 1), bprm->envc, &ptr_size) ||
552 check_mul_overflow(ptr_size, sizeo 552 check_mul_overflow(ptr_size, sizeof(void *), &ptr_size))
553 return -E2BIG; 553 return -E2BIG;
554 if (limit <= ptr_size) 554 if (limit <= ptr_size)
555 return -E2BIG; 555 return -E2BIG;
556 limit -= ptr_size; 556 limit -= ptr_size;
557 557
558 return bprm_set_stack_limit(bprm, limi 558 return bprm_set_stack_limit(bprm, limit);
559 } 559 }
560 560
561 /* 561 /*
562 * 'copy_strings()' copies argument/environmen 562 * 'copy_strings()' copies argument/environment strings from the old
563 * processes's memory to the new process's sta 563 * processes's memory to the new process's stack. The call to get_user_pages()
564 * ensures the destination page is created and 564 * ensures the destination page is created and not swapped out.
565 */ 565 */
566 static int copy_strings(int argc, struct user_ 566 static int copy_strings(int argc, struct user_arg_ptr argv,
567 struct linux_binprm *b 567 struct linux_binprm *bprm)
568 { 568 {
569 struct page *kmapped_page = NULL; 569 struct page *kmapped_page = NULL;
570 char *kaddr = NULL; 570 char *kaddr = NULL;
571 unsigned long kpos = 0; 571 unsigned long kpos = 0;
572 int ret; 572 int ret;
573 573
574 while (argc-- > 0) { 574 while (argc-- > 0) {
575 const char __user *str; 575 const char __user *str;
576 int len; 576 int len;
577 unsigned long pos; 577 unsigned long pos;
578 578
579 ret = -EFAULT; 579 ret = -EFAULT;
580 str = get_user_arg_ptr(argv, a 580 str = get_user_arg_ptr(argv, argc);
581 if (IS_ERR(str)) 581 if (IS_ERR(str))
582 goto out; 582 goto out;
583 583
584 len = strnlen_user(str, MAX_AR 584 len = strnlen_user(str, MAX_ARG_STRLEN);
585 if (!len) 585 if (!len)
586 goto out; 586 goto out;
587 587
588 ret = -E2BIG; 588 ret = -E2BIG;
589 if (!valid_arg_len(bprm, len)) 589 if (!valid_arg_len(bprm, len))
590 goto out; 590 goto out;
591 591
592 /* We're going to work our way 592 /* We're going to work our way backwards. */
593 pos = bprm->p; 593 pos = bprm->p;
594 str += len; 594 str += len;
595 bprm->p -= len; 595 bprm->p -= len;
596 if (bprm_hit_stack_limit(bprm) 596 if (bprm_hit_stack_limit(bprm))
597 goto out; 597 goto out;
598 598
599 while (len > 0) { 599 while (len > 0) {
600 int offset, bytes_to_c 600 int offset, bytes_to_copy;
601 601
602 if (fatal_signal_pendi 602 if (fatal_signal_pending(current)) {
603 ret = -ERESTAR 603 ret = -ERESTARTNOHAND;
604 goto out; 604 goto out;
605 } 605 }
606 cond_resched(); 606 cond_resched();
607 607
608 offset = pos % PAGE_SI 608 offset = pos % PAGE_SIZE;
609 if (offset == 0) 609 if (offset == 0)
610 offset = PAGE_ 610 offset = PAGE_SIZE;
611 611
612 bytes_to_copy = offset 612 bytes_to_copy = offset;
613 if (bytes_to_copy > le 613 if (bytes_to_copy > len)
614 bytes_to_copy 614 bytes_to_copy = len;
615 615
616 offset -= bytes_to_cop 616 offset -= bytes_to_copy;
617 pos -= bytes_to_copy; 617 pos -= bytes_to_copy;
618 str -= bytes_to_copy; 618 str -= bytes_to_copy;
619 len -= bytes_to_copy; 619 len -= bytes_to_copy;
620 620
621 if (!kmapped_page || k 621 if (!kmapped_page || kpos != (pos & PAGE_MASK)) {
622 struct page *p 622 struct page *page;
623 623
624 page = get_arg 624 page = get_arg_page(bprm, pos, 1);
625 if (!page) { 625 if (!page) {
626 ret = 626 ret = -E2BIG;
627 goto o 627 goto out;
628 } 628 }
629 629
630 if (kmapped_pa 630 if (kmapped_page) {
631 flush_ 631 flush_dcache_page(kmapped_page);
632 kunmap 632 kunmap_local(kaddr);
633 put_ar 633 put_arg_page(kmapped_page);
634 } 634 }
635 kmapped_page = 635 kmapped_page = page;
636 kaddr = kmap_l 636 kaddr = kmap_local_page(kmapped_page);
637 kpos = pos & P 637 kpos = pos & PAGE_MASK;
638 flush_arg_page 638 flush_arg_page(bprm, kpos, kmapped_page);
639 } 639 }
640 if (copy_from_user(kad 640 if (copy_from_user(kaddr+offset, str, bytes_to_copy)) {
641 ret = -EFAULT; 641 ret = -EFAULT;
642 goto out; 642 goto out;
643 } 643 }
644 } 644 }
645 } 645 }
646 ret = 0; 646 ret = 0;
647 out: 647 out:
648 if (kmapped_page) { 648 if (kmapped_page) {
649 flush_dcache_page(kmapped_page 649 flush_dcache_page(kmapped_page);
650 kunmap_local(kaddr); 650 kunmap_local(kaddr);
651 put_arg_page(kmapped_page); 651 put_arg_page(kmapped_page);
652 } 652 }
653 return ret; 653 return ret;
654 } 654 }
655 655
656 /* 656 /*
657 * Copy and argument/environment string from t 657 * Copy and argument/environment string from the kernel to the processes stack.
658 */ 658 */
659 int copy_string_kernel(const char *arg, struct 659 int copy_string_kernel(const char *arg, struct linux_binprm *bprm)
660 { 660 {
661 int len = strnlen(arg, MAX_ARG_STRLEN) 661 int len = strnlen(arg, MAX_ARG_STRLEN) + 1 /* terminating NUL */;
662 unsigned long pos = bprm->p; 662 unsigned long pos = bprm->p;
663 663
664 if (len == 0) 664 if (len == 0)
665 return -EFAULT; 665 return -EFAULT;
666 if (!valid_arg_len(bprm, len)) 666 if (!valid_arg_len(bprm, len))
667 return -E2BIG; 667 return -E2BIG;
668 668
669 /* We're going to work our way backwar 669 /* We're going to work our way backwards. */
670 arg += len; 670 arg += len;
671 bprm->p -= len; 671 bprm->p -= len;
672 if (bprm_hit_stack_limit(bprm)) 672 if (bprm_hit_stack_limit(bprm))
673 return -E2BIG; 673 return -E2BIG;
674 674
675 while (len > 0) { 675 while (len > 0) {
676 unsigned int bytes_to_copy = m 676 unsigned int bytes_to_copy = min_t(unsigned int, len,
677 min_not_zero(o 677 min_not_zero(offset_in_page(pos), PAGE_SIZE));
678 struct page *page; 678 struct page *page;
679 679
680 pos -= bytes_to_copy; 680 pos -= bytes_to_copy;
681 arg -= bytes_to_copy; 681 arg -= bytes_to_copy;
682 len -= bytes_to_copy; 682 len -= bytes_to_copy;
683 683
684 page = get_arg_page(bprm, pos, 684 page = get_arg_page(bprm, pos, 1);
685 if (!page) 685 if (!page)
686 return -E2BIG; 686 return -E2BIG;
687 flush_arg_page(bprm, pos & PAG 687 flush_arg_page(bprm, pos & PAGE_MASK, page);
688 memcpy_to_page(page, offset_in 688 memcpy_to_page(page, offset_in_page(pos), arg, bytes_to_copy);
689 put_arg_page(page); 689 put_arg_page(page);
690 } 690 }
691 691
692 return 0; 692 return 0;
693 } 693 }
694 EXPORT_SYMBOL(copy_string_kernel); 694 EXPORT_SYMBOL(copy_string_kernel);
695 695
696 static int copy_strings_kernel(int argc, const 696 static int copy_strings_kernel(int argc, const char *const *argv,
697 struct linux_bi 697 struct linux_binprm *bprm)
698 { 698 {
699 while (argc-- > 0) { 699 while (argc-- > 0) {
700 int ret = copy_string_kernel(a 700 int ret = copy_string_kernel(argv[argc], bprm);
701 if (ret < 0) 701 if (ret < 0)
702 return ret; 702 return ret;
703 if (fatal_signal_pending(curre 703 if (fatal_signal_pending(current))
704 return -ERESTARTNOHAND 704 return -ERESTARTNOHAND;
705 cond_resched(); 705 cond_resched();
706 } 706 }
707 return 0; 707 return 0;
708 } 708 }
709 709
710 #ifdef CONFIG_MMU 710 #ifdef CONFIG_MMU
711 711
712 /* 712 /*
713 * Finalizes the stack vm_area_struct. The fla 713 * Finalizes the stack vm_area_struct. The flags and permissions are updated,
714 * the stack is optionally relocated, and some 714 * the stack is optionally relocated, and some extra space is added.
715 */ 715 */
716 int setup_arg_pages(struct linux_binprm *bprm, 716 int setup_arg_pages(struct linux_binprm *bprm,
717 unsigned long stack_top, 717 unsigned long stack_top,
718 int executable_stack) 718 int executable_stack)
719 { 719 {
720 unsigned long ret; 720 unsigned long ret;
721 unsigned long stack_shift; 721 unsigned long stack_shift;
722 struct mm_struct *mm = current->mm; 722 struct mm_struct *mm = current->mm;
723 struct vm_area_struct *vma = bprm->vma 723 struct vm_area_struct *vma = bprm->vma;
724 struct vm_area_struct *prev = NULL; 724 struct vm_area_struct *prev = NULL;
725 unsigned long vm_flags; 725 unsigned long vm_flags;
726 unsigned long stack_base; 726 unsigned long stack_base;
727 unsigned long stack_size; 727 unsigned long stack_size;
728 unsigned long stack_expand; 728 unsigned long stack_expand;
729 unsigned long rlim_stack; 729 unsigned long rlim_stack;
730 struct mmu_gather tlb; 730 struct mmu_gather tlb;
731 struct vma_iterator vmi; 731 struct vma_iterator vmi;
732 732
733 #ifdef CONFIG_STACK_GROWSUP 733 #ifdef CONFIG_STACK_GROWSUP
734 /* Limit stack size */ 734 /* Limit stack size */
735 stack_base = bprm->rlim_stack.rlim_max 735 stack_base = bprm->rlim_stack.rlim_max;
736 736
737 stack_base = calc_max_stack_size(stack 737 stack_base = calc_max_stack_size(stack_base);
738 738
739 /* Add space for stack randomization. 739 /* Add space for stack randomization. */
740 if (current->flags & PF_RANDOMIZE) 740 if (current->flags & PF_RANDOMIZE)
741 stack_base += (STACK_RND_MASK 741 stack_base += (STACK_RND_MASK << PAGE_SHIFT);
742 742
743 /* Make sure we didn't let the argumen 743 /* Make sure we didn't let the argument array grow too large. */
744 if (vma->vm_end - vma->vm_start > stac 744 if (vma->vm_end - vma->vm_start > stack_base)
745 return -ENOMEM; 745 return -ENOMEM;
746 746
747 stack_base = PAGE_ALIGN(stack_top - st 747 stack_base = PAGE_ALIGN(stack_top - stack_base);
748 748
749 stack_shift = vma->vm_start - stack_ba 749 stack_shift = vma->vm_start - stack_base;
750 mm->arg_start = bprm->p - stack_shift; 750 mm->arg_start = bprm->p - stack_shift;
751 bprm->p = vma->vm_end - stack_shift; 751 bprm->p = vma->vm_end - stack_shift;
752 #else 752 #else
753 stack_top = arch_align_stack(stack_top 753 stack_top = arch_align_stack(stack_top);
754 stack_top = PAGE_ALIGN(stack_top); 754 stack_top = PAGE_ALIGN(stack_top);
755 755
756 if (unlikely(stack_top < mmap_min_addr 756 if (unlikely(stack_top < mmap_min_addr) ||
757 unlikely(vma->vm_end - vma->vm_sta 757 unlikely(vma->vm_end - vma->vm_start >= stack_top - mmap_min_addr))
758 return -ENOMEM; 758 return -ENOMEM;
759 759
760 stack_shift = vma->vm_end - stack_top; 760 stack_shift = vma->vm_end - stack_top;
761 761
762 bprm->p -= stack_shift; 762 bprm->p -= stack_shift;
763 mm->arg_start = bprm->p; 763 mm->arg_start = bprm->p;
764 #endif 764 #endif
765 765
766 if (bprm->loader) 766 if (bprm->loader)
767 bprm->loader -= stack_shift; 767 bprm->loader -= stack_shift;
768 bprm->exec -= stack_shift; 768 bprm->exec -= stack_shift;
769 769
770 if (mmap_write_lock_killable(mm)) 770 if (mmap_write_lock_killable(mm))
771 return -EINTR; 771 return -EINTR;
772 772
773 vm_flags = VM_STACK_FLAGS; 773 vm_flags = VM_STACK_FLAGS;
774 774
775 /* 775 /*
776 * Adjust stack execute permissions; e 776 * Adjust stack execute permissions; explicitly enable for
777 * EXSTACK_ENABLE_X, disable for EXSTA 777 * EXSTACK_ENABLE_X, disable for EXSTACK_DISABLE_X and leave alone
778 * (arch default) otherwise. 778 * (arch default) otherwise.
779 */ 779 */
780 if (unlikely(executable_stack == EXSTA 780 if (unlikely(executable_stack == EXSTACK_ENABLE_X))
781 vm_flags |= VM_EXEC; 781 vm_flags |= VM_EXEC;
782 else if (executable_stack == EXSTACK_D 782 else if (executable_stack == EXSTACK_DISABLE_X)
783 vm_flags &= ~VM_EXEC; 783 vm_flags &= ~VM_EXEC;
784 vm_flags |= mm->def_flags; 784 vm_flags |= mm->def_flags;
785 vm_flags |= VM_STACK_INCOMPLETE_SETUP; 785 vm_flags |= VM_STACK_INCOMPLETE_SETUP;
786 786
787 vma_iter_init(&vmi, mm, vma->vm_start) 787 vma_iter_init(&vmi, mm, vma->vm_start);
788 788
789 tlb_gather_mmu(&tlb, mm); 789 tlb_gather_mmu(&tlb, mm);
790 ret = mprotect_fixup(&vmi, &tlb, vma, 790 ret = mprotect_fixup(&vmi, &tlb, vma, &prev, vma->vm_start, vma->vm_end,
791 vm_flags); 791 vm_flags);
792 tlb_finish_mmu(&tlb); 792 tlb_finish_mmu(&tlb);
793 793
794 if (ret) 794 if (ret)
795 goto out_unlock; 795 goto out_unlock;
796 BUG_ON(prev != vma); 796 BUG_ON(prev != vma);
797 797
798 if (unlikely(vm_flags & VM_EXEC)) { 798 if (unlikely(vm_flags & VM_EXEC)) {
799 pr_warn_once("process '%pD4' s 799 pr_warn_once("process '%pD4' started with executable stack\n",
800 bprm->file); 800 bprm->file);
801 } 801 }
802 802
803 /* Move stack pages down in memory. */ 803 /* Move stack pages down in memory. */
804 if (stack_shift) { 804 if (stack_shift) {
805 /* 805 /*
806 * During bprm_mm_init(), we c 806 * During bprm_mm_init(), we create a temporary stack at STACK_TOP_MAX. Once
807 * the binfmt code determines 807 * the binfmt code determines where the new stack should reside, we shift it to
808 * its final location. 808 * its final location.
809 */ 809 */
810 ret = relocate_vma_down(vma, s 810 ret = relocate_vma_down(vma, stack_shift);
811 if (ret) 811 if (ret)
812 goto out_unlock; 812 goto out_unlock;
813 } 813 }
814 814
815 /* mprotect_fixup is overkill to remov 815 /* mprotect_fixup is overkill to remove the temporary stack flags */
816 vm_flags_clear(vma, VM_STACK_INCOMPLET 816 vm_flags_clear(vma, VM_STACK_INCOMPLETE_SETUP);
817 817
818 stack_expand = 131072UL; /* randomly 3 818 stack_expand = 131072UL; /* randomly 32*4k (or 2*64k) pages */
819 stack_size = vma->vm_end - vma->vm_sta 819 stack_size = vma->vm_end - vma->vm_start;
820 /* 820 /*
821 * Align this down to a page boundary 821 * Align this down to a page boundary as expand_stack
822 * will align it up. 822 * will align it up.
823 */ 823 */
824 rlim_stack = bprm->rlim_stack.rlim_cur 824 rlim_stack = bprm->rlim_stack.rlim_cur & PAGE_MASK;
825 825
826 stack_expand = min(rlim_stack, stack_s 826 stack_expand = min(rlim_stack, stack_size + stack_expand);
827 827
828 #ifdef CONFIG_STACK_GROWSUP 828 #ifdef CONFIG_STACK_GROWSUP
829 stack_base = vma->vm_start + stack_exp 829 stack_base = vma->vm_start + stack_expand;
830 #else 830 #else
831 stack_base = vma->vm_end - stack_expan 831 stack_base = vma->vm_end - stack_expand;
832 #endif 832 #endif
833 current->mm->start_stack = bprm->p; 833 current->mm->start_stack = bprm->p;
834 ret = expand_stack_locked(vma, stack_b 834 ret = expand_stack_locked(vma, stack_base);
835 if (ret) 835 if (ret)
836 ret = -EFAULT; 836 ret = -EFAULT;
837 837
838 out_unlock: 838 out_unlock:
839 mmap_write_unlock(mm); 839 mmap_write_unlock(mm);
840 return ret; 840 return ret;
841 } 841 }
842 EXPORT_SYMBOL(setup_arg_pages); 842 EXPORT_SYMBOL(setup_arg_pages);
843 843
844 #else 844 #else
845 845
846 /* 846 /*
847 * Transfer the program arguments and environm 847 * Transfer the program arguments and environment from the holding pages
848 * onto the stack. The provided stack pointer 848 * onto the stack. The provided stack pointer is adjusted accordingly.
849 */ 849 */
850 int transfer_args_to_stack(struct linux_binprm 850 int transfer_args_to_stack(struct linux_binprm *bprm,
851 unsigned long *sp_l 851 unsigned long *sp_location)
852 { 852 {
853 unsigned long index, stop, sp; 853 unsigned long index, stop, sp;
854 int ret = 0; 854 int ret = 0;
855 855
856 stop = bprm->p >> PAGE_SHIFT; 856 stop = bprm->p >> PAGE_SHIFT;
857 sp = *sp_location; 857 sp = *sp_location;
858 858
859 for (index = MAX_ARG_PAGES - 1; index 859 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
860 unsigned int offset = index == 860 unsigned int offset = index == stop ? bprm->p & ~PAGE_MASK : 0;
861 char *src = kmap_local_page(bp 861 char *src = kmap_local_page(bprm->page[index]) + offset;
862 sp -= PAGE_SIZE - offset; 862 sp -= PAGE_SIZE - offset;
863 if (copy_to_user((void *) sp, 863 if (copy_to_user((void *) sp, src, PAGE_SIZE - offset) != 0)
864 ret = -EFAULT; 864 ret = -EFAULT;
865 kunmap_local(src); 865 kunmap_local(src);
866 if (ret) 866 if (ret)
867 goto out; 867 goto out;
868 } 868 }
869 869
870 bprm->exec += *sp_location - MAX_ARG_P 870 bprm->exec += *sp_location - MAX_ARG_PAGES * PAGE_SIZE;
871 *sp_location = sp; 871 *sp_location = sp;
872 872
873 out: 873 out:
874 return ret; 874 return ret;
875 } 875 }
876 EXPORT_SYMBOL(transfer_args_to_stack); 876 EXPORT_SYMBOL(transfer_args_to_stack);
877 877
878 #endif /* CONFIG_MMU */ 878 #endif /* CONFIG_MMU */
879 879
880 /* 880 /*
881 * On success, caller must call do_close_execa 881 * On success, caller must call do_close_execat() on the returned
882 * struct file to close it. 882 * struct file to close it.
883 */ 883 */
884 static struct file *do_open_execat(int fd, str 884 static struct file *do_open_execat(int fd, struct filename *name, int flags)
885 { 885 {
886 struct file *file; 886 struct file *file;
887 struct open_flags open_exec_flags = { 887 struct open_flags open_exec_flags = {
888 .open_flag = O_LARGEFILE | O_R 888 .open_flag = O_LARGEFILE | O_RDONLY | __FMODE_EXEC,
889 .acc_mode = MAY_EXEC, 889 .acc_mode = MAY_EXEC,
890 .intent = LOOKUP_OPEN, 890 .intent = LOOKUP_OPEN,
891 .lookup_flags = LOOKUP_FOLLOW, 891 .lookup_flags = LOOKUP_FOLLOW,
892 }; 892 };
893 893
894 if ((flags & ~(AT_SYMLINK_NOFOLLOW | A 894 if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH)) != 0)
895 return ERR_PTR(-EINVAL); 895 return ERR_PTR(-EINVAL);
896 if (flags & AT_SYMLINK_NOFOLLOW) 896 if (flags & AT_SYMLINK_NOFOLLOW)
897 open_exec_flags.lookup_flags & 897 open_exec_flags.lookup_flags &= ~LOOKUP_FOLLOW;
898 if (flags & AT_EMPTY_PATH) 898 if (flags & AT_EMPTY_PATH)
899 open_exec_flags.lookup_flags | 899 open_exec_flags.lookup_flags |= LOOKUP_EMPTY;
900 900
901 file = do_filp_open(fd, name, &open_ex 901 file = do_filp_open(fd, name, &open_exec_flags);
902 if (IS_ERR(file)) 902 if (IS_ERR(file))
903 return file; 903 return file;
904 904
905 /* 905 /*
906 * In the past the regular type check 906 * In the past the regular type check was here. It moved to may_open() in
907 * 633fb6ac3980 ("exec: move S_ISREG() 907 * 633fb6ac3980 ("exec: move S_ISREG() check earlier"). Since then it is
908 * an invariant that all non-regular f 908 * an invariant that all non-regular files error out before we get here.
909 */ 909 */
910 if (WARN_ON_ONCE(!S_ISREG(file_inode(f 910 if (WARN_ON_ONCE(!S_ISREG(file_inode(file)->i_mode)) ||
911 path_noexec(&file->f_path)) { 911 path_noexec(&file->f_path)) {
912 fput(file); 912 fput(file);
913 return ERR_PTR(-EACCES); 913 return ERR_PTR(-EACCES);
914 } 914 }
915 915
916 return file; 916 return file;
917 } 917 }
918 918
919 /** 919 /**
920 * open_exec - Open a path name for execution 920 * open_exec - Open a path name for execution
921 * 921 *
922 * @name: path name to open with the intent of 922 * @name: path name to open with the intent of executing it.
923 * 923 *
924 * Returns ERR_PTR on failure or allocated str 924 * Returns ERR_PTR on failure or allocated struct file on success.
925 * 925 *
926 * As this is a wrapper for the internal do_op 926 * As this is a wrapper for the internal do_open_execat(). Also see
927 * do_close_execat(). 927 * do_close_execat().
928 */ 928 */
929 struct file *open_exec(const char *name) 929 struct file *open_exec(const char *name)
930 { 930 {
931 struct filename *filename = getname_ke 931 struct filename *filename = getname_kernel(name);
932 struct file *f = ERR_CAST(filename); 932 struct file *f = ERR_CAST(filename);
933 933
934 if (!IS_ERR(filename)) { 934 if (!IS_ERR(filename)) {
935 f = do_open_execat(AT_FDCWD, f 935 f = do_open_execat(AT_FDCWD, filename, 0);
936 putname(filename); 936 putname(filename);
937 } 937 }
938 return f; 938 return f;
939 } 939 }
940 EXPORT_SYMBOL(open_exec); 940 EXPORT_SYMBOL(open_exec);
941 941
942 #if defined(CONFIG_BINFMT_FLAT) || defined(CON 942 #if defined(CONFIG_BINFMT_FLAT) || defined(CONFIG_BINFMT_ELF_FDPIC)
943 ssize_t read_code(struct file *file, unsigned 943 ssize_t read_code(struct file *file, unsigned long addr, loff_t pos, size_t len)
944 { 944 {
945 ssize_t res = vfs_read(file, (void __u 945 ssize_t res = vfs_read(file, (void __user *)addr, len, &pos);
946 if (res > 0) 946 if (res > 0)
947 flush_icache_user_range(addr, 947 flush_icache_user_range(addr, addr + len);
948 return res; 948 return res;
949 } 949 }
950 EXPORT_SYMBOL(read_code); 950 EXPORT_SYMBOL(read_code);
951 #endif 951 #endif
952 952
953 /* 953 /*
954 * Maps the mm_struct mm into the current task 954 * Maps the mm_struct mm into the current task struct.
955 * On success, this function returns with exec 955 * On success, this function returns with exec_update_lock
956 * held for writing. 956 * held for writing.
957 */ 957 */
958 static int exec_mmap(struct mm_struct *mm) 958 static int exec_mmap(struct mm_struct *mm)
959 { 959 {
960 struct task_struct *tsk; 960 struct task_struct *tsk;
961 struct mm_struct *old_mm, *active_mm; 961 struct mm_struct *old_mm, *active_mm;
962 int ret; 962 int ret;
963 963
964 /* Notify parent that we're no longer 964 /* Notify parent that we're no longer interested in the old VM */
965 tsk = current; 965 tsk = current;
966 old_mm = current->mm; 966 old_mm = current->mm;
967 exec_mm_release(tsk, old_mm); 967 exec_mm_release(tsk, old_mm);
968 968
969 ret = down_write_killable(&tsk->signal 969 ret = down_write_killable(&tsk->signal->exec_update_lock);
970 if (ret) 970 if (ret)
971 return ret; 971 return ret;
972 972
973 if (old_mm) { 973 if (old_mm) {
974 /* 974 /*
975 * If there is a pending fatal 975 * If there is a pending fatal signal perhaps a signal
976 * whose default action is to 976 * whose default action is to create a coredump get
977 * out and die instead of goin 977 * out and die instead of going through with the exec.
978 */ 978 */
979 ret = mmap_read_lock_killable( 979 ret = mmap_read_lock_killable(old_mm);
980 if (ret) { 980 if (ret) {
981 up_write(&tsk->signal- 981 up_write(&tsk->signal->exec_update_lock);
982 return ret; 982 return ret;
983 } 983 }
984 } 984 }
985 985
986 task_lock(tsk); 986 task_lock(tsk);
987 membarrier_exec_mmap(mm); 987 membarrier_exec_mmap(mm);
988 988
989 local_irq_disable(); 989 local_irq_disable();
990 active_mm = tsk->active_mm; 990 active_mm = tsk->active_mm;
991 tsk->active_mm = mm; 991 tsk->active_mm = mm;
992 tsk->mm = mm; 992 tsk->mm = mm;
993 mm_init_cid(mm); 993 mm_init_cid(mm);
994 /* 994 /*
995 * This prevents preemption while acti 995 * This prevents preemption while active_mm is being loaded and
996 * it and mm are being updated, which 996 * it and mm are being updated, which could cause problems for
997 * lazy tlb mm refcounting when these 997 * lazy tlb mm refcounting when these are updated by context
998 * switches. Not all architectures can 998 * switches. Not all architectures can handle irqs off over
999 * activate_mm yet. 999 * activate_mm yet.
1000 */ 1000 */
1001 if (!IS_ENABLED(CONFIG_ARCH_WANT_IRQS 1001 if (!IS_ENABLED(CONFIG_ARCH_WANT_IRQS_OFF_ACTIVATE_MM))
1002 local_irq_enable(); 1002 local_irq_enable();
1003 activate_mm(active_mm, mm); 1003 activate_mm(active_mm, mm);
1004 if (IS_ENABLED(CONFIG_ARCH_WANT_IRQS_ 1004 if (IS_ENABLED(CONFIG_ARCH_WANT_IRQS_OFF_ACTIVATE_MM))
1005 local_irq_enable(); 1005 local_irq_enable();
1006 lru_gen_add_mm(mm); 1006 lru_gen_add_mm(mm);
1007 task_unlock(tsk); 1007 task_unlock(tsk);
1008 lru_gen_use_mm(mm); 1008 lru_gen_use_mm(mm);
1009 if (old_mm) { 1009 if (old_mm) {
1010 mmap_read_unlock(old_mm); 1010 mmap_read_unlock(old_mm);
1011 BUG_ON(active_mm != old_mm); 1011 BUG_ON(active_mm != old_mm);
1012 setmax_mm_hiwater_rss(&tsk->s 1012 setmax_mm_hiwater_rss(&tsk->signal->maxrss, old_mm);
1013 mm_update_next_owner(old_mm); 1013 mm_update_next_owner(old_mm);
1014 mmput(old_mm); 1014 mmput(old_mm);
1015 return 0; 1015 return 0;
1016 } 1016 }
1017 mmdrop_lazy_tlb(active_mm); 1017 mmdrop_lazy_tlb(active_mm);
1018 return 0; 1018 return 0;
1019 } 1019 }
1020 1020
1021 static int de_thread(struct task_struct *tsk) 1021 static int de_thread(struct task_struct *tsk)
1022 { 1022 {
1023 struct signal_struct *sig = tsk->sign 1023 struct signal_struct *sig = tsk->signal;
1024 struct sighand_struct *oldsighand = t 1024 struct sighand_struct *oldsighand = tsk->sighand;
1025 spinlock_t *lock = &oldsighand->siglo 1025 spinlock_t *lock = &oldsighand->siglock;
1026 1026
1027 if (thread_group_empty(tsk)) 1027 if (thread_group_empty(tsk))
1028 goto no_thread_group; 1028 goto no_thread_group;
1029 1029
1030 /* 1030 /*
1031 * Kill all other threads in the thre 1031 * Kill all other threads in the thread group.
1032 */ 1032 */
1033 spin_lock_irq(lock); 1033 spin_lock_irq(lock);
1034 if ((sig->flags & SIGNAL_GROUP_EXIT) 1034 if ((sig->flags & SIGNAL_GROUP_EXIT) || sig->group_exec_task) {
1035 /* 1035 /*
1036 * Another group action in pr 1036 * Another group action in progress, just
1037 * return so that the signal 1037 * return so that the signal is processed.
1038 */ 1038 */
1039 spin_unlock_irq(lock); 1039 spin_unlock_irq(lock);
1040 return -EAGAIN; 1040 return -EAGAIN;
1041 } 1041 }
1042 1042
1043 sig->group_exec_task = tsk; 1043 sig->group_exec_task = tsk;
1044 sig->notify_count = zap_other_threads 1044 sig->notify_count = zap_other_threads(tsk);
1045 if (!thread_group_leader(tsk)) 1045 if (!thread_group_leader(tsk))
1046 sig->notify_count--; 1046 sig->notify_count--;
1047 1047
1048 while (sig->notify_count) { 1048 while (sig->notify_count) {
1049 __set_current_state(TASK_KILL 1049 __set_current_state(TASK_KILLABLE);
1050 spin_unlock_irq(lock); 1050 spin_unlock_irq(lock);
1051 schedule(); 1051 schedule();
1052 if (__fatal_signal_pending(ts 1052 if (__fatal_signal_pending(tsk))
1053 goto killed; 1053 goto killed;
1054 spin_lock_irq(lock); 1054 spin_lock_irq(lock);
1055 } 1055 }
1056 spin_unlock_irq(lock); 1056 spin_unlock_irq(lock);
1057 1057
1058 /* 1058 /*
1059 * At this point all other threads ha 1059 * At this point all other threads have exited, all we have to
1060 * do is to wait for the thread group 1060 * do is to wait for the thread group leader to become inactive,
1061 * and to assume its PID: 1061 * and to assume its PID:
1062 */ 1062 */
1063 if (!thread_group_leader(tsk)) { 1063 if (!thread_group_leader(tsk)) {
1064 struct task_struct *leader = 1064 struct task_struct *leader = tsk->group_leader;
1065 1065
1066 for (;;) { 1066 for (;;) {
1067 cgroup_threadgroup_ch 1067 cgroup_threadgroup_change_begin(tsk);
1068 write_lock_irq(&taskl 1068 write_lock_irq(&tasklist_lock);
1069 /* 1069 /*
1070 * Do this under task 1070 * Do this under tasklist_lock to ensure that
1071 * exit_notify() can' 1071 * exit_notify() can't miss ->group_exec_task
1072 */ 1072 */
1073 sig->notify_count = - 1073 sig->notify_count = -1;
1074 if (likely(leader->ex 1074 if (likely(leader->exit_state))
1075 break; 1075 break;
1076 __set_current_state(T 1076 __set_current_state(TASK_KILLABLE);
1077 write_unlock_irq(&tas 1077 write_unlock_irq(&tasklist_lock);
1078 cgroup_threadgroup_ch 1078 cgroup_threadgroup_change_end(tsk);
1079 schedule(); 1079 schedule();
1080 if (__fatal_signal_pe 1080 if (__fatal_signal_pending(tsk))
1081 goto killed; 1081 goto killed;
1082 } 1082 }
1083 1083
1084 /* 1084 /*
1085 * The only record we have of 1085 * The only record we have of the real-time age of a
1086 * process, regardless of exe 1086 * process, regardless of execs it's done, is start_time.
1087 * All the past CPU time is a 1087 * All the past CPU time is accumulated in signal_struct
1088 * from sister threads now de 1088 * from sister threads now dead. But in this non-leader
1089 * exec, nothing survives fro 1089 * exec, nothing survives from the original leader thread,
1090 * whose birth marks the true 1090 * whose birth marks the true age of this process now.
1091 * When we take on its identi 1091 * When we take on its identity by switching to its PID, we
1092 * also take its birthdate (a 1092 * also take its birthdate (always earlier than our own).
1093 */ 1093 */
1094 tsk->start_time = leader->sta 1094 tsk->start_time = leader->start_time;
1095 tsk->start_boottime = leader- 1095 tsk->start_boottime = leader->start_boottime;
1096 1096
1097 BUG_ON(!same_thread_group(lea 1097 BUG_ON(!same_thread_group(leader, tsk));
1098 /* 1098 /*
1099 * An exec() starts a new thr 1099 * An exec() starts a new thread group with the
1100 * TGID of the previous threa 1100 * TGID of the previous thread group. Rehash the
1101 * two threads with a switche 1101 * two threads with a switched PID, and release
1102 * the former thread group le 1102 * the former thread group leader:
1103 */ 1103 */
1104 1104
1105 /* Become a process group lea 1105 /* Become a process group leader with the old leader's pid.
1106 * The old leader becomes a t 1106 * The old leader becomes a thread of the this thread group.
1107 */ 1107 */
1108 exchange_tids(tsk, leader); 1108 exchange_tids(tsk, leader);
1109 transfer_pid(leader, tsk, PID 1109 transfer_pid(leader, tsk, PIDTYPE_TGID);
1110 transfer_pid(leader, tsk, PID 1110 transfer_pid(leader, tsk, PIDTYPE_PGID);
1111 transfer_pid(leader, tsk, PID 1111 transfer_pid(leader, tsk, PIDTYPE_SID);
1112 1112
1113 list_replace_rcu(&leader->tas 1113 list_replace_rcu(&leader->tasks, &tsk->tasks);
1114 list_replace_init(&leader->si 1114 list_replace_init(&leader->sibling, &tsk->sibling);
1115 1115
1116 tsk->group_leader = tsk; 1116 tsk->group_leader = tsk;
1117 leader->group_leader = tsk; 1117 leader->group_leader = tsk;
1118 1118
1119 tsk->exit_signal = SIGCHLD; 1119 tsk->exit_signal = SIGCHLD;
1120 leader->exit_signal = -1; 1120 leader->exit_signal = -1;
1121 1121
1122 BUG_ON(leader->exit_state != 1122 BUG_ON(leader->exit_state != EXIT_ZOMBIE);
1123 leader->exit_state = EXIT_DEA 1123 leader->exit_state = EXIT_DEAD;
1124 /* 1124 /*
1125 * We are going to release_ta 1125 * We are going to release_task()->ptrace_unlink() silently,
1126 * the tracer can sleep in do 1126 * the tracer can sleep in do_wait(). EXIT_DEAD guarantees
1127 * the tracer won't block aga 1127 * the tracer won't block again waiting for this thread.
1128 */ 1128 */
1129 if (unlikely(leader->ptrace)) 1129 if (unlikely(leader->ptrace))
1130 __wake_up_parent(lead 1130 __wake_up_parent(leader, leader->parent);
1131 write_unlock_irq(&tasklist_lo 1131 write_unlock_irq(&tasklist_lock);
1132 cgroup_threadgroup_change_end 1132 cgroup_threadgroup_change_end(tsk);
1133 1133
1134 release_task(leader); 1134 release_task(leader);
1135 } 1135 }
1136 1136
1137 sig->group_exec_task = NULL; 1137 sig->group_exec_task = NULL;
1138 sig->notify_count = 0; 1138 sig->notify_count = 0;
1139 1139
1140 no_thread_group: 1140 no_thread_group:
1141 /* we have changed execution domain * 1141 /* we have changed execution domain */
1142 tsk->exit_signal = SIGCHLD; 1142 tsk->exit_signal = SIGCHLD;
1143 1143
1144 BUG_ON(!thread_group_leader(tsk)); 1144 BUG_ON(!thread_group_leader(tsk));
1145 return 0; 1145 return 0;
1146 1146
1147 killed: 1147 killed:
1148 /* protects against exit_notify() and 1148 /* protects against exit_notify() and __exit_signal() */
1149 read_lock(&tasklist_lock); 1149 read_lock(&tasklist_lock);
1150 sig->group_exec_task = NULL; 1150 sig->group_exec_task = NULL;
1151 sig->notify_count = 0; 1151 sig->notify_count = 0;
1152 read_unlock(&tasklist_lock); 1152 read_unlock(&tasklist_lock);
1153 return -EAGAIN; 1153 return -EAGAIN;
1154 } 1154 }
1155 1155
1156 1156
1157 /* 1157 /*
1158 * This function makes sure the current proce 1158 * This function makes sure the current process has its own signal table,
1159 * so that flush_signal_handlers can later re 1159 * so that flush_signal_handlers can later reset the handlers without
1160 * disturbing other processes. (Other proces 1160 * disturbing other processes. (Other processes might share the signal
1161 * table via the CLONE_SIGHAND option to clon 1161 * table via the CLONE_SIGHAND option to clone().)
1162 */ 1162 */
1163 static int unshare_sighand(struct task_struct 1163 static int unshare_sighand(struct task_struct *me)
1164 { 1164 {
1165 struct sighand_struct *oldsighand = m 1165 struct sighand_struct *oldsighand = me->sighand;
1166 1166
1167 if (refcount_read(&oldsighand->count) 1167 if (refcount_read(&oldsighand->count) != 1) {
1168 struct sighand_struct *newsig 1168 struct sighand_struct *newsighand;
1169 /* 1169 /*
1170 * This ->sighand is shared w 1170 * This ->sighand is shared with the CLONE_SIGHAND
1171 * but not CLONE_THREAD task, 1171 * but not CLONE_THREAD task, switch to the new one.
1172 */ 1172 */
1173 newsighand = kmem_cache_alloc 1173 newsighand = kmem_cache_alloc(sighand_cachep, GFP_KERNEL);
1174 if (!newsighand) 1174 if (!newsighand)
1175 return -ENOMEM; 1175 return -ENOMEM;
1176 1176
1177 refcount_set(&newsighand->cou 1177 refcount_set(&newsighand->count, 1);
1178 1178
1179 write_lock_irq(&tasklist_lock 1179 write_lock_irq(&tasklist_lock);
1180 spin_lock(&oldsighand->sigloc 1180 spin_lock(&oldsighand->siglock);
1181 memcpy(newsighand->action, ol 1181 memcpy(newsighand->action, oldsighand->action,
1182 sizeof(newsighand->act 1182 sizeof(newsighand->action));
1183 rcu_assign_pointer(me->sighan 1183 rcu_assign_pointer(me->sighand, newsighand);
1184 spin_unlock(&oldsighand->sigl 1184 spin_unlock(&oldsighand->siglock);
1185 write_unlock_irq(&tasklist_lo 1185 write_unlock_irq(&tasklist_lock);
1186 1186
1187 __cleanup_sighand(oldsighand) 1187 __cleanup_sighand(oldsighand);
1188 } 1188 }
1189 return 0; 1189 return 0;
1190 } 1190 }
1191 1191
1192 char *__get_task_comm(char *buf, size_t buf_s 1192 char *__get_task_comm(char *buf, size_t buf_size, struct task_struct *tsk)
1193 { 1193 {
1194 task_lock(tsk); 1194 task_lock(tsk);
1195 /* Always NUL terminated and zero-pad 1195 /* Always NUL terminated and zero-padded */
1196 strscpy_pad(buf, tsk->comm, buf_size) 1196 strscpy_pad(buf, tsk->comm, buf_size);
1197 task_unlock(tsk); 1197 task_unlock(tsk);
1198 return buf; 1198 return buf;
1199 } 1199 }
1200 EXPORT_SYMBOL_GPL(__get_task_comm); 1200 EXPORT_SYMBOL_GPL(__get_task_comm);
1201 1201
1202 /* 1202 /*
1203 * These functions flushes out all traces of 1203 * These functions flushes out all traces of the currently running executable
1204 * so that a new one can be started 1204 * so that a new one can be started
1205 */ 1205 */
1206 1206
1207 void __set_task_comm(struct task_struct *tsk, 1207 void __set_task_comm(struct task_struct *tsk, const char *buf, bool exec)
1208 { 1208 {
1209 task_lock(tsk); 1209 task_lock(tsk);
1210 trace_task_rename(tsk, buf); 1210 trace_task_rename(tsk, buf);
1211 strscpy_pad(tsk->comm, buf, sizeof(ts 1211 strscpy_pad(tsk->comm, buf, sizeof(tsk->comm));
1212 task_unlock(tsk); 1212 task_unlock(tsk);
1213 perf_event_comm(tsk, exec); 1213 perf_event_comm(tsk, exec);
1214 } 1214 }
1215 1215
1216 /* 1216 /*
1217 * Calling this is the point of no return. No 1217 * Calling this is the point of no return. None of the failures will be
1218 * seen by userspace since either the process 1218 * seen by userspace since either the process is already taking a fatal
1219 * signal (via de_thread() or coredump), or w 1219 * signal (via de_thread() or coredump), or will have SEGV raised
1220 * (after exec_mmap()) by search_binary_handl 1220 * (after exec_mmap()) by search_binary_handler (see below).
1221 */ 1221 */
1222 int begin_new_exec(struct linux_binprm * bprm 1222 int begin_new_exec(struct linux_binprm * bprm)
1223 { 1223 {
1224 struct task_struct *me = current; 1224 struct task_struct *me = current;
1225 int retval; 1225 int retval;
1226 1226
1227 /* Once we are committed compute the 1227 /* Once we are committed compute the creds */
1228 retval = bprm_creds_from_file(bprm); 1228 retval = bprm_creds_from_file(bprm);
1229 if (retval) 1229 if (retval)
1230 return retval; 1230 return retval;
1231 1231
1232 /* 1232 /*
1233 * This tracepoint marks the point be 1233 * This tracepoint marks the point before flushing the old exec where
1234 * the current task is still unchange 1234 * the current task is still unchanged, but errors are fatal (point of
1235 * no return). The later "sched_proce 1235 * no return). The later "sched_process_exec" tracepoint is called after
1236 * the current task has successfully 1236 * the current task has successfully switched to the new exec.
1237 */ 1237 */
1238 trace_sched_prepare_exec(current, bpr 1238 trace_sched_prepare_exec(current, bprm);
1239 1239
1240 /* 1240 /*
1241 * Ensure all future errors are fatal 1241 * Ensure all future errors are fatal.
1242 */ 1242 */
1243 bprm->point_of_no_return = true; 1243 bprm->point_of_no_return = true;
1244 1244
1245 /* 1245 /*
1246 * Make this the only thread in the t 1246 * Make this the only thread in the thread group.
1247 */ 1247 */
1248 retval = de_thread(me); 1248 retval = de_thread(me);
1249 if (retval) 1249 if (retval)
1250 goto out; 1250 goto out;
1251 1251
1252 /* 1252 /*
1253 * Cancel any io_uring activity acros 1253 * Cancel any io_uring activity across execve
1254 */ 1254 */
1255 io_uring_task_cancel(); 1255 io_uring_task_cancel();
1256 1256
1257 /* Ensure the files table is not shar 1257 /* Ensure the files table is not shared. */
1258 retval = unshare_files(); 1258 retval = unshare_files();
1259 if (retval) 1259 if (retval)
1260 goto out; 1260 goto out;
1261 1261
1262 /* 1262 /*
1263 * Must be called _before_ exec_mmap( 1263 * Must be called _before_ exec_mmap() as bprm->mm is
1264 * not visible until then. Doing it h 1264 * not visible until then. Doing it here also ensures
1265 * we don't race against replace_mm_e 1265 * we don't race against replace_mm_exe_file().
1266 */ 1266 */
1267 retval = set_mm_exe_file(bprm->mm, bp 1267 retval = set_mm_exe_file(bprm->mm, bprm->file);
1268 if (retval) 1268 if (retval)
1269 goto out; 1269 goto out;
1270 1270
1271 /* If the binary is not readable then 1271 /* If the binary is not readable then enforce mm->dumpable=0 */
1272 would_dump(bprm, bprm->file); 1272 would_dump(bprm, bprm->file);
1273 if (bprm->have_execfd) 1273 if (bprm->have_execfd)
1274 would_dump(bprm, bprm->execut 1274 would_dump(bprm, bprm->executable);
1275 1275
1276 /* 1276 /*
1277 * Release all of the old mmap stuff 1277 * Release all of the old mmap stuff
1278 */ 1278 */
1279 acct_arg_size(bprm, 0); 1279 acct_arg_size(bprm, 0);
1280 retval = exec_mmap(bprm->mm); 1280 retval = exec_mmap(bprm->mm);
1281 if (retval) 1281 if (retval)
1282 goto out; 1282 goto out;
1283 1283
1284 bprm->mm = NULL; 1284 bprm->mm = NULL;
1285 1285
1286 retval = exec_task_namespaces(); 1286 retval = exec_task_namespaces();
1287 if (retval) 1287 if (retval)
1288 goto out_unlock; 1288 goto out_unlock;
1289 1289
1290 #ifdef CONFIG_POSIX_TIMERS 1290 #ifdef CONFIG_POSIX_TIMERS
1291 spin_lock_irq(&me->sighand->siglock); 1291 spin_lock_irq(&me->sighand->siglock);
1292 posix_cpu_timers_exit(me); 1292 posix_cpu_timers_exit(me);
1293 spin_unlock_irq(&me->sighand->siglock 1293 spin_unlock_irq(&me->sighand->siglock);
1294 exit_itimers(me); 1294 exit_itimers(me);
1295 flush_itimer_signals(); 1295 flush_itimer_signals();
1296 #endif 1296 #endif
1297 1297
1298 /* 1298 /*
1299 * Make the signal table private. 1299 * Make the signal table private.
1300 */ 1300 */
1301 retval = unshare_sighand(me); 1301 retval = unshare_sighand(me);
1302 if (retval) 1302 if (retval)
1303 goto out_unlock; 1303 goto out_unlock;
1304 1304
1305 me->flags &= ~(PF_RANDOMIZE | PF_FORK 1305 me->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC |
1306 PF_NO 1306 PF_NOFREEZE | PF_NO_SETAFFINITY);
1307 flush_thread(); 1307 flush_thread();
1308 me->personality &= ~bprm->per_clear; 1308 me->personality &= ~bprm->per_clear;
1309 1309
1310 clear_syscall_work_syscall_user_dispa 1310 clear_syscall_work_syscall_user_dispatch(me);
1311 1311
1312 /* 1312 /*
1313 * We have to apply CLOEXEC before we 1313 * We have to apply CLOEXEC before we change whether the process is
1314 * dumpable (in setup_new_exec) to av 1314 * dumpable (in setup_new_exec) to avoid a race with a process in userspace
1315 * trying to access the should-be-clo 1315 * trying to access the should-be-closed file descriptors of a process
1316 * undergoing exec(2). 1316 * undergoing exec(2).
1317 */ 1317 */
1318 do_close_on_exec(me->files); 1318 do_close_on_exec(me->files);
1319 1319
1320 if (bprm->secureexec) { 1320 if (bprm->secureexec) {
1321 /* Make sure parent cannot si 1321 /* Make sure parent cannot signal privileged process. */
1322 me->pdeath_signal = 0; 1322 me->pdeath_signal = 0;
1323 1323
1324 /* 1324 /*
1325 * For secureexec, reset the 1325 * For secureexec, reset the stack limit to sane default to
1326 * avoid bad behavior from th 1326 * avoid bad behavior from the prior rlimits. This has to
1327 * happen before arch_pick_mm 1327 * happen before arch_pick_mmap_layout(), which examines
1328 * RLIMIT_STACK, but after th 1328 * RLIMIT_STACK, but after the point of no return to avoid
1329 * needing to clean up the ch 1329 * needing to clean up the change on failure.
1330 */ 1330 */
1331 if (bprm->rlim_stack.rlim_cur 1331 if (bprm->rlim_stack.rlim_cur > _STK_LIM)
1332 bprm->rlim_stack.rlim 1332 bprm->rlim_stack.rlim_cur = _STK_LIM;
1333 } 1333 }
1334 1334
1335 me->sas_ss_sp = me->sas_ss_size = 0; 1335 me->sas_ss_sp = me->sas_ss_size = 0;
1336 1336
1337 /* 1337 /*
1338 * Figure out dumpability. Note that 1338 * Figure out dumpability. Note that this checking only of current
1339 * is wrong, but userspace depends on 1339 * is wrong, but userspace depends on it. This should be testing
1340 * bprm->secureexec instead. 1340 * bprm->secureexec instead.
1341 */ 1341 */
1342 if (bprm->interp_flags & BINPRM_FLAGS 1342 if (bprm->interp_flags & BINPRM_FLAGS_ENFORCE_NONDUMP ||
1343 !(uid_eq(current_euid(), current_ 1343 !(uid_eq(current_euid(), current_uid()) &&
1344 gid_eq(current_egid(), current_ 1344 gid_eq(current_egid(), current_gid())))
1345 set_dumpable(current->mm, sui 1345 set_dumpable(current->mm, suid_dumpable);
1346 else 1346 else
1347 set_dumpable(current->mm, SUI 1347 set_dumpable(current->mm, SUID_DUMP_USER);
1348 1348
1349 perf_event_exec(); 1349 perf_event_exec();
1350 __set_task_comm(me, kbasename(bprm->f 1350 __set_task_comm(me, kbasename(bprm->filename), true);
1351 1351
1352 /* An exec changes our domain. We are 1352 /* An exec changes our domain. We are no longer part of the thread
1353 group */ 1353 group */
1354 WRITE_ONCE(me->self_exec_id, me->self 1354 WRITE_ONCE(me->self_exec_id, me->self_exec_id + 1);
1355 flush_signal_handlers(me, 0); 1355 flush_signal_handlers(me, 0);
1356 1356
1357 retval = set_cred_ucounts(bprm->cred) 1357 retval = set_cred_ucounts(bprm->cred);
1358 if (retval < 0) 1358 if (retval < 0)
1359 goto out_unlock; 1359 goto out_unlock;
1360 1360
1361 /* 1361 /*
1362 * install the new credentials for th 1362 * install the new credentials for this executable
1363 */ 1363 */
1364 security_bprm_committing_creds(bprm); 1364 security_bprm_committing_creds(bprm);
1365 1365
1366 commit_creds(bprm->cred); 1366 commit_creds(bprm->cred);
1367 bprm->cred = NULL; 1367 bprm->cred = NULL;
1368 1368
1369 /* 1369 /*
1370 * Disable monitoring for regular use 1370 * Disable monitoring for regular users
1371 * when executing setuid binaries. Mu 1371 * when executing setuid binaries. Must
1372 * wait until new credentials are com 1372 * wait until new credentials are committed
1373 * by commit_creds() above 1373 * by commit_creds() above
1374 */ 1374 */
1375 if (get_dumpable(me->mm) != SUID_DUMP 1375 if (get_dumpable(me->mm) != SUID_DUMP_USER)
1376 perf_event_exit_task(me); 1376 perf_event_exit_task(me);
1377 /* 1377 /*
1378 * cred_guard_mutex must be held at l 1378 * cred_guard_mutex must be held at least to this point to prevent
1379 * ptrace_attach() from altering our 1379 * ptrace_attach() from altering our determination of the task's
1380 * credentials; any time after this i 1380 * credentials; any time after this it may be unlocked.
1381 */ 1381 */
1382 security_bprm_committed_creds(bprm); 1382 security_bprm_committed_creds(bprm);
1383 1383
1384 /* Pass the opened binary to the inte 1384 /* Pass the opened binary to the interpreter. */
1385 if (bprm->have_execfd) { 1385 if (bprm->have_execfd) {
1386 retval = get_unused_fd_flags( 1386 retval = get_unused_fd_flags(0);
1387 if (retval < 0) 1387 if (retval < 0)
1388 goto out_unlock; 1388 goto out_unlock;
1389 fd_install(retval, bprm->exec 1389 fd_install(retval, bprm->executable);
1390 bprm->executable = NULL; 1390 bprm->executable = NULL;
1391 bprm->execfd = retval; 1391 bprm->execfd = retval;
1392 } 1392 }
1393 return 0; 1393 return 0;
1394 1394
1395 out_unlock: 1395 out_unlock:
1396 up_write(&me->signal->exec_update_loc 1396 up_write(&me->signal->exec_update_lock);
1397 if (!bprm->cred) 1397 if (!bprm->cred)
1398 mutex_unlock(&me->signal->cre 1398 mutex_unlock(&me->signal->cred_guard_mutex);
1399 1399
1400 out: 1400 out:
1401 return retval; 1401 return retval;
1402 } 1402 }
1403 EXPORT_SYMBOL(begin_new_exec); 1403 EXPORT_SYMBOL(begin_new_exec);
1404 1404
1405 void would_dump(struct linux_binprm *bprm, st 1405 void would_dump(struct linux_binprm *bprm, struct file *file)
1406 { 1406 {
1407 struct inode *inode = file_inode(file 1407 struct inode *inode = file_inode(file);
1408 struct mnt_idmap *idmap = file_mnt_id 1408 struct mnt_idmap *idmap = file_mnt_idmap(file);
1409 if (inode_permission(idmap, inode, MA 1409 if (inode_permission(idmap, inode, MAY_READ) < 0) {
1410 struct user_namespace *old, * 1410 struct user_namespace *old, *user_ns;
1411 bprm->interp_flags |= BINPRM_ 1411 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
1412 1412
1413 /* Ensure mm->user_ns contain 1413 /* Ensure mm->user_ns contains the executable */
1414 user_ns = old = bprm->mm->use 1414 user_ns = old = bprm->mm->user_ns;
1415 while ((user_ns != &init_user 1415 while ((user_ns != &init_user_ns) &&
1416 !privileged_wrt_inode_ 1416 !privileged_wrt_inode_uidgid(user_ns, idmap, inode))
1417 user_ns = user_ns->pa 1417 user_ns = user_ns->parent;
1418 1418
1419 if (old != user_ns) { 1419 if (old != user_ns) {
1420 bprm->mm->user_ns = g 1420 bprm->mm->user_ns = get_user_ns(user_ns);
1421 put_user_ns(old); 1421 put_user_ns(old);
1422 } 1422 }
1423 } 1423 }
1424 } 1424 }
1425 EXPORT_SYMBOL(would_dump); 1425 EXPORT_SYMBOL(would_dump);
1426 1426
1427 void setup_new_exec(struct linux_binprm * bpr 1427 void setup_new_exec(struct linux_binprm * bprm)
1428 { 1428 {
1429 /* Setup things that can depend upon 1429 /* Setup things that can depend upon the personality */
1430 struct task_struct *me = current; 1430 struct task_struct *me = current;
1431 1431
1432 arch_pick_mmap_layout(me->mm, &bprm-> 1432 arch_pick_mmap_layout(me->mm, &bprm->rlim_stack);
1433 1433
1434 arch_setup_new_exec(); 1434 arch_setup_new_exec();
1435 1435
1436 /* Set the new mm task size. We have 1436 /* Set the new mm task size. We have to do that late because it may
1437 * depend on TIF_32BIT which is only 1437 * depend on TIF_32BIT which is only updated in flush_thread() on
1438 * some architectures like powerpc 1438 * some architectures like powerpc
1439 */ 1439 */
1440 me->mm->task_size = TASK_SIZE; 1440 me->mm->task_size = TASK_SIZE;
1441 up_write(&me->signal->exec_update_loc 1441 up_write(&me->signal->exec_update_lock);
1442 mutex_unlock(&me->signal->cred_guard_ 1442 mutex_unlock(&me->signal->cred_guard_mutex);
1443 } 1443 }
1444 EXPORT_SYMBOL(setup_new_exec); 1444 EXPORT_SYMBOL(setup_new_exec);
1445 1445
1446 /* Runs immediately before start_thread() tak 1446 /* Runs immediately before start_thread() takes over. */
1447 void finalize_exec(struct linux_binprm *bprm) 1447 void finalize_exec(struct linux_binprm *bprm)
1448 { 1448 {
1449 /* Store any stack rlimit changes bef 1449 /* Store any stack rlimit changes before starting thread. */
1450 task_lock(current->group_leader); 1450 task_lock(current->group_leader);
1451 current->signal->rlim[RLIMIT_STACK] = 1451 current->signal->rlim[RLIMIT_STACK] = bprm->rlim_stack;
1452 task_unlock(current->group_leader); 1452 task_unlock(current->group_leader);
1453 } 1453 }
1454 EXPORT_SYMBOL(finalize_exec); 1454 EXPORT_SYMBOL(finalize_exec);
1455 1455
1456 /* 1456 /*
1457 * Prepare credentials and lock ->cred_guard_ 1457 * Prepare credentials and lock ->cred_guard_mutex.
1458 * setup_new_exec() commits the new creds and 1458 * setup_new_exec() commits the new creds and drops the lock.
1459 * Or, if exec fails before, free_bprm() shou 1459 * Or, if exec fails before, free_bprm() should release ->cred
1460 * and unlock. 1460 * and unlock.
1461 */ 1461 */
1462 static int prepare_bprm_creds(struct linux_bi 1462 static int prepare_bprm_creds(struct linux_binprm *bprm)
1463 { 1463 {
1464 if (mutex_lock_interruptible(¤t 1464 if (mutex_lock_interruptible(¤t->signal->cred_guard_mutex))
1465 return -ERESTARTNOINTR; 1465 return -ERESTARTNOINTR;
1466 1466
1467 bprm->cred = prepare_exec_creds(); 1467 bprm->cred = prepare_exec_creds();
1468 if (likely(bprm->cred)) 1468 if (likely(bprm->cred))
1469 return 0; 1469 return 0;
1470 1470
1471 mutex_unlock(¤t->signal->cred_g 1471 mutex_unlock(¤t->signal->cred_guard_mutex);
1472 return -ENOMEM; 1472 return -ENOMEM;
1473 } 1473 }
1474 1474
1475 /* Matches do_open_execat() */ 1475 /* Matches do_open_execat() */
1476 static void do_close_execat(struct file *file 1476 static void do_close_execat(struct file *file)
1477 { 1477 {
1478 if (file) 1478 if (file)
1479 fput(file); 1479 fput(file);
1480 } 1480 }
1481 1481
1482 static void free_bprm(struct linux_binprm *bp 1482 static void free_bprm(struct linux_binprm *bprm)
1483 { 1483 {
1484 if (bprm->mm) { 1484 if (bprm->mm) {
1485 acct_arg_size(bprm, 0); 1485 acct_arg_size(bprm, 0);
1486 mmput(bprm->mm); 1486 mmput(bprm->mm);
1487 } 1487 }
1488 free_arg_pages(bprm); 1488 free_arg_pages(bprm);
1489 if (bprm->cred) { 1489 if (bprm->cred) {
1490 mutex_unlock(¤t->signal 1490 mutex_unlock(¤t->signal->cred_guard_mutex);
1491 abort_creds(bprm->cred); 1491 abort_creds(bprm->cred);
1492 } 1492 }
1493 do_close_execat(bprm->file); 1493 do_close_execat(bprm->file);
1494 if (bprm->executable) 1494 if (bprm->executable)
1495 fput(bprm->executable); 1495 fput(bprm->executable);
1496 /* If a binfmt changed the interp, fr 1496 /* If a binfmt changed the interp, free it. */
1497 if (bprm->interp != bprm->filename) 1497 if (bprm->interp != bprm->filename)
1498 kfree(bprm->interp); 1498 kfree(bprm->interp);
1499 kfree(bprm->fdpath); 1499 kfree(bprm->fdpath);
1500 kfree(bprm); 1500 kfree(bprm);
1501 } 1501 }
1502 1502
1503 static struct linux_binprm *alloc_bprm(int fd 1503 static struct linux_binprm *alloc_bprm(int fd, struct filename *filename, int flags)
1504 { 1504 {
1505 struct linux_binprm *bprm; 1505 struct linux_binprm *bprm;
1506 struct file *file; 1506 struct file *file;
1507 int retval = -ENOMEM; 1507 int retval = -ENOMEM;
1508 1508
1509 file = do_open_execat(fd, filename, f 1509 file = do_open_execat(fd, filename, flags);
1510 if (IS_ERR(file)) 1510 if (IS_ERR(file))
1511 return ERR_CAST(file); 1511 return ERR_CAST(file);
1512 1512
1513 bprm = kzalloc(sizeof(*bprm), GFP_KER 1513 bprm = kzalloc(sizeof(*bprm), GFP_KERNEL);
1514 if (!bprm) { 1514 if (!bprm) {
1515 do_close_execat(file); 1515 do_close_execat(file);
1516 return ERR_PTR(-ENOMEM); 1516 return ERR_PTR(-ENOMEM);
1517 } 1517 }
1518 1518
1519 bprm->file = file; 1519 bprm->file = file;
1520 1520
1521 if (fd == AT_FDCWD || filename->name[ 1521 if (fd == AT_FDCWD || filename->name[0] == '/') {
1522 bprm->filename = filename->na 1522 bprm->filename = filename->name;
1523 } else { 1523 } else {
1524 if (filename->name[0] == '\0' 1524 if (filename->name[0] == '\0')
1525 bprm->fdpath = kaspri 1525 bprm->fdpath = kasprintf(GFP_KERNEL, "/dev/fd/%d", fd);
1526 else 1526 else
1527 bprm->fdpath = kaspri 1527 bprm->fdpath = kasprintf(GFP_KERNEL, "/dev/fd/%d/%s",
1528 1528 fd, filename->name);
1529 if (!bprm->fdpath) 1529 if (!bprm->fdpath)
1530 goto out_free; 1530 goto out_free;
1531 1531
1532 /* 1532 /*
1533 * Record that a name derived 1533 * Record that a name derived from an O_CLOEXEC fd will be
1534 * inaccessible after exec. 1534 * inaccessible after exec. This allows the code in exec to
1535 * choose to fail when the ex 1535 * choose to fail when the executable is not mmaped into the
1536 * interpreter and an open fi 1536 * interpreter and an open file descriptor is not passed to
1537 * the interpreter. This mak 1537 * the interpreter. This makes for a better user experience
1538 * than having the interprete 1538 * than having the interpreter start and then immediately fail
1539 * when it finds the executab 1539 * when it finds the executable is inaccessible.
1540 */ 1540 */
1541 if (get_close_on_exec(fd)) 1541 if (get_close_on_exec(fd))
1542 bprm->interp_flags |= 1542 bprm->interp_flags |= BINPRM_FLAGS_PATH_INACCESSIBLE;
1543 1543
1544 bprm->filename = bprm->fdpath 1544 bprm->filename = bprm->fdpath;
1545 } 1545 }
1546 bprm->interp = bprm->filename; 1546 bprm->interp = bprm->filename;
1547 1547
1548 retval = bprm_mm_init(bprm); 1548 retval = bprm_mm_init(bprm);
1549 if (!retval) 1549 if (!retval)
1550 return bprm; 1550 return bprm;
1551 1551
1552 out_free: 1552 out_free:
1553 free_bprm(bprm); 1553 free_bprm(bprm);
1554 return ERR_PTR(retval); 1554 return ERR_PTR(retval);
1555 } 1555 }
1556 1556
1557 int bprm_change_interp(const char *interp, st 1557 int bprm_change_interp(const char *interp, struct linux_binprm *bprm)
1558 { 1558 {
1559 /* If a binfmt changed the interp, fr 1559 /* If a binfmt changed the interp, free it first. */
1560 if (bprm->interp != bprm->filename) 1560 if (bprm->interp != bprm->filename)
1561 kfree(bprm->interp); 1561 kfree(bprm->interp);
1562 bprm->interp = kstrdup(interp, GFP_KE 1562 bprm->interp = kstrdup(interp, GFP_KERNEL);
1563 if (!bprm->interp) 1563 if (!bprm->interp)
1564 return -ENOMEM; 1564 return -ENOMEM;
1565 return 0; 1565 return 0;
1566 } 1566 }
1567 EXPORT_SYMBOL(bprm_change_interp); 1567 EXPORT_SYMBOL(bprm_change_interp);
1568 1568
1569 /* 1569 /*
1570 * determine how safe it is to execute the pr 1570 * determine how safe it is to execute the proposed program
1571 * - the caller must hold ->cred_guard_mutex 1571 * - the caller must hold ->cred_guard_mutex to protect against
1572 * PTRACE_ATTACH or seccomp thread-sync 1572 * PTRACE_ATTACH or seccomp thread-sync
1573 */ 1573 */
1574 static void check_unsafe_exec(struct linux_bi 1574 static void check_unsafe_exec(struct linux_binprm *bprm)
1575 { 1575 {
1576 struct task_struct *p = current, *t; 1576 struct task_struct *p = current, *t;
1577 unsigned n_fs; 1577 unsigned n_fs;
1578 1578
1579 if (p->ptrace) 1579 if (p->ptrace)
1580 bprm->unsafe |= LSM_UNSAFE_PT 1580 bprm->unsafe |= LSM_UNSAFE_PTRACE;
1581 1581
1582 /* 1582 /*
1583 * This isn't strictly necessary, but 1583 * This isn't strictly necessary, but it makes it harder for LSMs to
1584 * mess up. 1584 * mess up.
1585 */ 1585 */
1586 if (task_no_new_privs(current)) 1586 if (task_no_new_privs(current))
1587 bprm->unsafe |= LSM_UNSAFE_NO 1587 bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS;
1588 1588
1589 /* 1589 /*
1590 * If another task is sharing our fs, 1590 * If another task is sharing our fs, we cannot safely
1591 * suid exec because the differently 1591 * suid exec because the differently privileged task
1592 * will be able to manipulate the cur 1592 * will be able to manipulate the current directory, etc.
1593 * It would be nice to force an unsha 1593 * It would be nice to force an unshare instead...
1594 */ 1594 */
1595 n_fs = 1; 1595 n_fs = 1;
1596 spin_lock(&p->fs->lock); 1596 spin_lock(&p->fs->lock);
1597 rcu_read_lock(); 1597 rcu_read_lock();
1598 for_other_threads(p, t) { 1598 for_other_threads(p, t) {
1599 if (t->fs == p->fs) 1599 if (t->fs == p->fs)
1600 n_fs++; 1600 n_fs++;
1601 } 1601 }
1602 rcu_read_unlock(); 1602 rcu_read_unlock();
1603 1603
1604 /* "users" and "in_exec" locked for c 1604 /* "users" and "in_exec" locked for copy_fs() */
1605 if (p->fs->users > n_fs) 1605 if (p->fs->users > n_fs)
1606 bprm->unsafe |= LSM_UNSAFE_SH 1606 bprm->unsafe |= LSM_UNSAFE_SHARE;
1607 else 1607 else
1608 p->fs->in_exec = 1; 1608 p->fs->in_exec = 1;
1609 spin_unlock(&p->fs->lock); 1609 spin_unlock(&p->fs->lock);
1610 } 1610 }
1611 1611
1612 static void bprm_fill_uid(struct linux_binprm 1612 static void bprm_fill_uid(struct linux_binprm *bprm, struct file *file)
1613 { 1613 {
1614 /* Handle suid and sgid on files */ 1614 /* Handle suid and sgid on files */
1615 struct mnt_idmap *idmap; 1615 struct mnt_idmap *idmap;
1616 struct inode *inode = file_inode(file 1616 struct inode *inode = file_inode(file);
1617 unsigned int mode; 1617 unsigned int mode;
1618 vfsuid_t vfsuid; 1618 vfsuid_t vfsuid;
1619 vfsgid_t vfsgid; 1619 vfsgid_t vfsgid;
1620 int err; 1620 int err;
1621 1621
1622 if (!mnt_may_suid(file->f_path.mnt)) 1622 if (!mnt_may_suid(file->f_path.mnt))
1623 return; 1623 return;
1624 1624
1625 if (task_no_new_privs(current)) 1625 if (task_no_new_privs(current))
1626 return; 1626 return;
1627 1627
1628 mode = READ_ONCE(inode->i_mode); 1628 mode = READ_ONCE(inode->i_mode);
1629 if (!(mode & (S_ISUID|S_ISGID))) 1629 if (!(mode & (S_ISUID|S_ISGID)))
1630 return; 1630 return;
1631 1631
1632 idmap = file_mnt_idmap(file); 1632 idmap = file_mnt_idmap(file);
1633 1633
1634 /* Be careful if suid/sgid is set */ 1634 /* Be careful if suid/sgid is set */
1635 inode_lock(inode); 1635 inode_lock(inode);
1636 1636
1637 /* Atomically reload and check mode/u 1637 /* Atomically reload and check mode/uid/gid now that lock held. */
1638 mode = inode->i_mode; 1638 mode = inode->i_mode;
1639 vfsuid = i_uid_into_vfsuid(idmap, ino 1639 vfsuid = i_uid_into_vfsuid(idmap, inode);
1640 vfsgid = i_gid_into_vfsgid(idmap, ino 1640 vfsgid = i_gid_into_vfsgid(idmap, inode);
1641 err = inode_permission(idmap, inode, 1641 err = inode_permission(idmap, inode, MAY_EXEC);
1642 inode_unlock(inode); 1642 inode_unlock(inode);
1643 1643
1644 /* Did the exec bit vanish out from u 1644 /* Did the exec bit vanish out from under us? Give up. */
1645 if (err) 1645 if (err)
1646 return; 1646 return;
1647 1647
1648 /* We ignore suid/sgid if there are n 1648 /* We ignore suid/sgid if there are no mappings for them in the ns */
1649 if (!vfsuid_has_mapping(bprm->cred->u 1649 if (!vfsuid_has_mapping(bprm->cred->user_ns, vfsuid) ||
1650 !vfsgid_has_mapping(bprm->cred->u 1650 !vfsgid_has_mapping(bprm->cred->user_ns, vfsgid))
1651 return; 1651 return;
1652 1652
1653 if (mode & S_ISUID) { 1653 if (mode & S_ISUID) {
1654 bprm->per_clear |= PER_CLEAR_ 1654 bprm->per_clear |= PER_CLEAR_ON_SETID;
1655 bprm->cred->euid = vfsuid_int 1655 bprm->cred->euid = vfsuid_into_kuid(vfsuid);
1656 } 1656 }
1657 1657
1658 if ((mode & (S_ISGID | S_IXGRP)) == ( 1658 if ((mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP)) {
1659 bprm->per_clear |= PER_CLEAR_ 1659 bprm->per_clear |= PER_CLEAR_ON_SETID;
1660 bprm->cred->egid = vfsgid_int 1660 bprm->cred->egid = vfsgid_into_kgid(vfsgid);
1661 } 1661 }
1662 } 1662 }
1663 1663
1664 /* 1664 /*
1665 * Compute brpm->cred based upon the final bi 1665 * Compute brpm->cred based upon the final binary.
1666 */ 1666 */
1667 static int bprm_creds_from_file(struct linux_ 1667 static int bprm_creds_from_file(struct linux_binprm *bprm)
1668 { 1668 {
1669 /* Compute creds based on which file? 1669 /* Compute creds based on which file? */
1670 struct file *file = bprm->execfd_cred 1670 struct file *file = bprm->execfd_creds ? bprm->executable : bprm->file;
1671 1671
1672 bprm_fill_uid(bprm, file); 1672 bprm_fill_uid(bprm, file);
1673 return security_bprm_creds_from_file( 1673 return security_bprm_creds_from_file(bprm, file);
1674 } 1674 }
1675 1675
1676 /* 1676 /*
1677 * Fill the binprm structure from the inode. 1677 * Fill the binprm structure from the inode.
1678 * Read the first BINPRM_BUF_SIZE bytes 1678 * Read the first BINPRM_BUF_SIZE bytes
1679 * 1679 *
1680 * This may be called multiple times for bina 1680 * This may be called multiple times for binary chains (scripts for example).
1681 */ 1681 */
1682 static int prepare_binprm(struct linux_binprm 1682 static int prepare_binprm(struct linux_binprm *bprm)
1683 { 1683 {
1684 loff_t pos = 0; 1684 loff_t pos = 0;
1685 1685
1686 memset(bprm->buf, 0, BINPRM_BUF_SIZE) 1686 memset(bprm->buf, 0, BINPRM_BUF_SIZE);
1687 return kernel_read(bprm->file, bprm-> 1687 return kernel_read(bprm->file, bprm->buf, BINPRM_BUF_SIZE, &pos);
1688 } 1688 }
1689 1689
1690 /* 1690 /*
1691 * Arguments are '\0' separated strings found 1691 * Arguments are '\0' separated strings found at the location bprm->p
1692 * points to; chop off the first by relocatin 1692 * points to; chop off the first by relocating brpm->p to right after
1693 * the first '\0' encountered. 1693 * the first '\0' encountered.
1694 */ 1694 */
1695 int remove_arg_zero(struct linux_binprm *bprm 1695 int remove_arg_zero(struct linux_binprm *bprm)
1696 { 1696 {
1697 unsigned long offset; 1697 unsigned long offset;
1698 char *kaddr; 1698 char *kaddr;
1699 struct page *page; 1699 struct page *page;
1700 1700
1701 if (!bprm->argc) 1701 if (!bprm->argc)
1702 return 0; 1702 return 0;
1703 1703
1704 do { 1704 do {
1705 offset = bprm->p & ~PAGE_MASK 1705 offset = bprm->p & ~PAGE_MASK;
1706 page = get_arg_page(bprm, bpr 1706 page = get_arg_page(bprm, bprm->p, 0);
1707 if (!page) 1707 if (!page)
1708 return -EFAULT; 1708 return -EFAULT;
1709 kaddr = kmap_local_page(page) 1709 kaddr = kmap_local_page(page);
1710 1710
1711 for (; offset < PAGE_SIZE && 1711 for (; offset < PAGE_SIZE && kaddr[offset];
1712 offset++, bpr 1712 offset++, bprm->p++)
1713 ; 1713 ;
1714 1714
1715 kunmap_local(kaddr); 1715 kunmap_local(kaddr);
1716 put_arg_page(page); 1716 put_arg_page(page);
1717 } while (offset == PAGE_SIZE); 1717 } while (offset == PAGE_SIZE);
1718 1718
1719 bprm->p++; 1719 bprm->p++;
1720 bprm->argc--; 1720 bprm->argc--;
1721 1721
1722 return 0; 1722 return 0;
1723 } 1723 }
1724 EXPORT_SYMBOL(remove_arg_zero); 1724 EXPORT_SYMBOL(remove_arg_zero);
1725 1725
1726 #define printable(c) (((c)=='\t') || ((c)=='\ 1726 #define printable(c) (((c)=='\t') || ((c)=='\n') || (0x20<=(c) && (c)<=0x7e))
1727 /* 1727 /*
1728 * cycle the list of binary formats handler, 1728 * cycle the list of binary formats handler, until one recognizes the image
1729 */ 1729 */
1730 static int search_binary_handler(struct linux 1730 static int search_binary_handler(struct linux_binprm *bprm)
1731 { 1731 {
1732 bool need_retry = IS_ENABLED(CONFIG_M 1732 bool need_retry = IS_ENABLED(CONFIG_MODULES);
1733 struct linux_binfmt *fmt; 1733 struct linux_binfmt *fmt;
1734 int retval; 1734 int retval;
1735 1735
1736 retval = prepare_binprm(bprm); 1736 retval = prepare_binprm(bprm);
1737 if (retval < 0) 1737 if (retval < 0)
1738 return retval; 1738 return retval;
1739 1739
1740 retval = security_bprm_check(bprm); 1740 retval = security_bprm_check(bprm);
1741 if (retval) 1741 if (retval)
1742 return retval; 1742 return retval;
1743 1743
1744 retval = -ENOENT; 1744 retval = -ENOENT;
1745 retry: 1745 retry:
1746 read_lock(&binfmt_lock); 1746 read_lock(&binfmt_lock);
1747 list_for_each_entry(fmt, &formats, lh 1747 list_for_each_entry(fmt, &formats, lh) {
1748 if (!try_module_get(fmt->modu 1748 if (!try_module_get(fmt->module))
1749 continue; 1749 continue;
1750 read_unlock(&binfmt_lock); 1750 read_unlock(&binfmt_lock);
1751 1751
1752 retval = fmt->load_binary(bpr 1752 retval = fmt->load_binary(bprm);
1753 1753
1754 read_lock(&binfmt_lock); 1754 read_lock(&binfmt_lock);
1755 put_binfmt(fmt); 1755 put_binfmt(fmt);
1756 if (bprm->point_of_no_return 1756 if (bprm->point_of_no_return || (retval != -ENOEXEC)) {
1757 read_unlock(&binfmt_l 1757 read_unlock(&binfmt_lock);
1758 return retval; 1758 return retval;
1759 } 1759 }
1760 } 1760 }
1761 read_unlock(&binfmt_lock); 1761 read_unlock(&binfmt_lock);
1762 1762
1763 if (need_retry) { 1763 if (need_retry) {
1764 if (printable(bprm->buf[0]) & 1764 if (printable(bprm->buf[0]) && printable(bprm->buf[1]) &&
1765 printable(bprm->buf[2]) & 1765 printable(bprm->buf[2]) && printable(bprm->buf[3]))
1766 return retval; 1766 return retval;
1767 if (request_module("binfmt-%0 1767 if (request_module("binfmt-%04x", *(ushort *)(bprm->buf + 2)) < 0)
1768 return retval; 1768 return retval;
1769 need_retry = false; 1769 need_retry = false;
1770 goto retry; 1770 goto retry;
1771 } 1771 }
1772 1772
1773 return retval; 1773 return retval;
1774 } 1774 }
1775 1775
1776 /* binfmt handlers will call back into begin_ 1776 /* binfmt handlers will call back into begin_new_exec() on success. */
1777 static int exec_binprm(struct linux_binprm *b 1777 static int exec_binprm(struct linux_binprm *bprm)
1778 { 1778 {
1779 pid_t old_pid, old_vpid; 1779 pid_t old_pid, old_vpid;
1780 int ret, depth; 1780 int ret, depth;
1781 1781
1782 /* Need to fetch pid before load_bina 1782 /* Need to fetch pid before load_binary changes it */
1783 old_pid = current->pid; 1783 old_pid = current->pid;
1784 rcu_read_lock(); 1784 rcu_read_lock();
1785 old_vpid = task_pid_nr_ns(current, ta 1785 old_vpid = task_pid_nr_ns(current, task_active_pid_ns(current->parent));
1786 rcu_read_unlock(); 1786 rcu_read_unlock();
1787 1787
1788 /* This allows 4 levels of binfmt rew 1788 /* This allows 4 levels of binfmt rewrites before failing hard. */
1789 for (depth = 0;; depth++) { 1789 for (depth = 0;; depth++) {
1790 struct file *exec; 1790 struct file *exec;
1791 if (depth > 5) 1791 if (depth > 5)
1792 return -ELOOP; 1792 return -ELOOP;
1793 1793
1794 ret = search_binary_handler(b 1794 ret = search_binary_handler(bprm);
1795 if (ret < 0) 1795 if (ret < 0)
1796 return ret; 1796 return ret;
1797 if (!bprm->interpreter) 1797 if (!bprm->interpreter)
1798 break; 1798 break;
1799 1799
1800 exec = bprm->file; 1800 exec = bprm->file;
1801 bprm->file = bprm->interprete 1801 bprm->file = bprm->interpreter;
1802 bprm->interpreter = NULL; 1802 bprm->interpreter = NULL;
1803 1803
1804 if (unlikely(bprm->have_execf 1804 if (unlikely(bprm->have_execfd)) {
1805 if (bprm->executable) 1805 if (bprm->executable) {
1806 fput(exec); 1806 fput(exec);
1807 return -ENOEX 1807 return -ENOEXEC;
1808 } 1808 }
1809 bprm->executable = ex 1809 bprm->executable = exec;
1810 } else 1810 } else
1811 fput(exec); 1811 fput(exec);
1812 } 1812 }
1813 1813
1814 audit_bprm(bprm); 1814 audit_bprm(bprm);
1815 trace_sched_process_exec(current, old 1815 trace_sched_process_exec(current, old_pid, bprm);
1816 ptrace_event(PTRACE_EVENT_EXEC, old_v 1816 ptrace_event(PTRACE_EVENT_EXEC, old_vpid);
1817 proc_exec_connector(current); 1817 proc_exec_connector(current);
1818 return 0; 1818 return 0;
1819 } 1819 }
1820 1820
1821 static int bprm_execve(struct linux_binprm *b 1821 static int bprm_execve(struct linux_binprm *bprm)
1822 { 1822 {
1823 int retval; 1823 int retval;
1824 1824
1825 retval = prepare_bprm_creds(bprm); 1825 retval = prepare_bprm_creds(bprm);
1826 if (retval) 1826 if (retval)
1827 return retval; 1827 return retval;
1828 1828
1829 /* 1829 /*
1830 * Check for unsafe execution states 1830 * Check for unsafe execution states before exec_binprm(), which
1831 * will call back into begin_new_exec 1831 * will call back into begin_new_exec(), into bprm_creds_from_file(),
1832 * where setuid-ness is evaluated. 1832 * where setuid-ness is evaluated.
1833 */ 1833 */
1834 check_unsafe_exec(bprm); 1834 check_unsafe_exec(bprm);
1835 current->in_execve = 1; 1835 current->in_execve = 1;
1836 sched_mm_cid_before_execve(current); 1836 sched_mm_cid_before_execve(current);
1837 1837
1838 sched_exec(); 1838 sched_exec();
1839 1839
1840 /* Set the unchanging part of bprm->c 1840 /* Set the unchanging part of bprm->cred */
1841 retval = security_bprm_creds_for_exec 1841 retval = security_bprm_creds_for_exec(bprm);
1842 if (retval) 1842 if (retval)
1843 goto out; 1843 goto out;
1844 1844
1845 retval = ccs_exec_binprm(bprm); 1845 retval = ccs_exec_binprm(bprm);
1846 if (retval < 0) 1846 if (retval < 0)
1847 goto out; 1847 goto out;
1848 1848
1849 sched_mm_cid_after_execve(current); 1849 sched_mm_cid_after_execve(current);
1850 /* execve succeeded */ 1850 /* execve succeeded */
1851 current->fs->in_exec = 0; 1851 current->fs->in_exec = 0;
1852 current->in_execve = 0; 1852 current->in_execve = 0;
1853 rseq_execve(current); 1853 rseq_execve(current);
1854 user_events_execve(current); 1854 user_events_execve(current);
1855 acct_update_integrals(current); 1855 acct_update_integrals(current);
1856 task_numa_free(current, false); 1856 task_numa_free(current, false);
1857 return retval; 1857 return retval;
1858 1858
1859 out: 1859 out:
1860 /* 1860 /*
1861 * If past the point of no return ens 1861 * If past the point of no return ensure the code never
1862 * returns to the userspace process. 1862 * returns to the userspace process. Use an existing fatal
1863 * signal if present otherwise termin 1863 * signal if present otherwise terminate the process with
1864 * SIGSEGV. 1864 * SIGSEGV.
1865 */ 1865 */
1866 if (bprm->point_of_no_return && !fata 1866 if (bprm->point_of_no_return && !fatal_signal_pending(current))
1867 force_fatal_sig(SIGSEGV); 1867 force_fatal_sig(SIGSEGV);
1868 1868
1869 sched_mm_cid_after_execve(current); 1869 sched_mm_cid_after_execve(current);
1870 current->fs->in_exec = 0; 1870 current->fs->in_exec = 0;
1871 current->in_execve = 0; 1871 current->in_execve = 0;
1872 1872
1873 return retval; 1873 return retval;
1874 } 1874 }
1875 1875
1876 static int do_execveat_common(int fd, struct 1876 static int do_execveat_common(int fd, struct filename *filename,
1877 struct user_arg 1877 struct user_arg_ptr argv,
1878 struct user_arg 1878 struct user_arg_ptr envp,
1879 int flags) 1879 int flags)
1880 { 1880 {
1881 struct linux_binprm *bprm; 1881 struct linux_binprm *bprm;
1882 int retval; 1882 int retval;
1883 1883
1884 if (IS_ERR(filename)) 1884 if (IS_ERR(filename))
1885 return PTR_ERR(filename); 1885 return PTR_ERR(filename);
1886 1886
1887 /* 1887 /*
1888 * We move the actual failure in case 1888 * We move the actual failure in case of RLIMIT_NPROC excess from
1889 * set*uid() to execve() because too 1889 * set*uid() to execve() because too many poorly written programs
1890 * don't check setuid() return code. 1890 * don't check setuid() return code. Here we additionally recheck
1891 * whether NPROC limit is still excee 1891 * whether NPROC limit is still exceeded.
1892 */ 1892 */
1893 if ((current->flags & PF_NPROC_EXCEED 1893 if ((current->flags & PF_NPROC_EXCEEDED) &&
1894 is_rlimit_overlimit(current_ucoun 1894 is_rlimit_overlimit(current_ucounts(), UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC))) {
1895 retval = -EAGAIN; 1895 retval = -EAGAIN;
1896 goto out_ret; 1896 goto out_ret;
1897 } 1897 }
1898 1898
1899 /* We're below the limit (still or ag 1899 /* We're below the limit (still or again), so we don't want to make
1900 * further execve() calls fail. */ 1900 * further execve() calls fail. */
1901 current->flags &= ~PF_NPROC_EXCEEDED; 1901 current->flags &= ~PF_NPROC_EXCEEDED;
1902 1902
1903 bprm = alloc_bprm(fd, filename, flags 1903 bprm = alloc_bprm(fd, filename, flags);
1904 if (IS_ERR(bprm)) { 1904 if (IS_ERR(bprm)) {
1905 retval = PTR_ERR(bprm); 1905 retval = PTR_ERR(bprm);
1906 goto out_ret; 1906 goto out_ret;
1907 } 1907 }
1908 1908
1909 retval = count(argv, MAX_ARG_STRINGS) 1909 retval = count(argv, MAX_ARG_STRINGS);
1910 if (retval == 0) 1910 if (retval == 0)
1911 pr_warn_once("process '%s' la 1911 pr_warn_once("process '%s' launched '%s' with NULL argv: empty string added\n",
1912 current->comm, b 1912 current->comm, bprm->filename);
1913 if (retval < 0) 1913 if (retval < 0)
1914 goto out_free; 1914 goto out_free;
1915 bprm->argc = retval; 1915 bprm->argc = retval;
1916 1916
1917 retval = count(envp, MAX_ARG_STRINGS) 1917 retval = count(envp, MAX_ARG_STRINGS);
1918 if (retval < 0) 1918 if (retval < 0)
1919 goto out_free; 1919 goto out_free;
1920 bprm->envc = retval; 1920 bprm->envc = retval;
1921 1921
1922 retval = bprm_stack_limits(bprm); 1922 retval = bprm_stack_limits(bprm);
1923 if (retval < 0) 1923 if (retval < 0)
1924 goto out_free; 1924 goto out_free;
1925 1925
1926 retval = copy_string_kernel(bprm->fil 1926 retval = copy_string_kernel(bprm->filename, bprm);
1927 if (retval < 0) 1927 if (retval < 0)
1928 goto out_free; 1928 goto out_free;
1929 bprm->exec = bprm->p; 1929 bprm->exec = bprm->p;
1930 1930
1931 retval = copy_strings(bprm->envc, env 1931 retval = copy_strings(bprm->envc, envp, bprm);
1932 if (retval < 0) 1932 if (retval < 0)
1933 goto out_free; 1933 goto out_free;
1934 1934
1935 retval = copy_strings(bprm->argc, arg 1935 retval = copy_strings(bprm->argc, argv, bprm);
1936 if (retval < 0) 1936 if (retval < 0)
1937 goto out_free; 1937 goto out_free;
1938 1938
1939 /* 1939 /*
1940 * When argv is empty, add an empty s 1940 * When argv is empty, add an empty string ("") as argv[0] to
1941 * ensure confused userspace programs 1941 * ensure confused userspace programs that start processing
1942 * from argv[1] won't end up walking 1942 * from argv[1] won't end up walking envp. See also
1943 * bprm_stack_limits(). 1943 * bprm_stack_limits().
1944 */ 1944 */
1945 if (bprm->argc == 0) { 1945 if (bprm->argc == 0) {
1946 retval = copy_string_kernel(" 1946 retval = copy_string_kernel("", bprm);
1947 if (retval < 0) 1947 if (retval < 0)
1948 goto out_free; 1948 goto out_free;
1949 bprm->argc = 1; 1949 bprm->argc = 1;
1950 } 1950 }
1951 1951
1952 retval = bprm_execve(bprm); 1952 retval = bprm_execve(bprm);
1953 out_free: 1953 out_free:
1954 free_bprm(bprm); 1954 free_bprm(bprm);
1955 1955
1956 out_ret: 1956 out_ret:
1957 putname(filename); 1957 putname(filename);
1958 return retval; 1958 return retval;
1959 } 1959 }
1960 1960
1961 int kernel_execve(const char *kernel_filename 1961 int kernel_execve(const char *kernel_filename,
1962 const char *const *argv, co 1962 const char *const *argv, const char *const *envp)
1963 { 1963 {
1964 struct filename *filename; 1964 struct filename *filename;
1965 struct linux_binprm *bprm; 1965 struct linux_binprm *bprm;
1966 int fd = AT_FDCWD; 1966 int fd = AT_FDCWD;
1967 int retval; 1967 int retval;
1968 1968
1969 /* It is non-sense for kernel threads 1969 /* It is non-sense for kernel threads to call execve */
1970 if (WARN_ON_ONCE(current->flags & PF_ 1970 if (WARN_ON_ONCE(current->flags & PF_KTHREAD))
1971 return -EINVAL; 1971 return -EINVAL;
1972 1972
1973 filename = getname_kernel(kernel_file 1973 filename = getname_kernel(kernel_filename);
1974 if (IS_ERR(filename)) 1974 if (IS_ERR(filename))
1975 return PTR_ERR(filename); 1975 return PTR_ERR(filename);
1976 1976
1977 bprm = alloc_bprm(fd, filename, 0); 1977 bprm = alloc_bprm(fd, filename, 0);
1978 if (IS_ERR(bprm)) { 1978 if (IS_ERR(bprm)) {
1979 retval = PTR_ERR(bprm); 1979 retval = PTR_ERR(bprm);
1980 goto out_ret; 1980 goto out_ret;
1981 } 1981 }
1982 1982
1983 retval = count_strings_kernel(argv); 1983 retval = count_strings_kernel(argv);
1984 if (WARN_ON_ONCE(retval == 0)) 1984 if (WARN_ON_ONCE(retval == 0))
1985 retval = -EINVAL; 1985 retval = -EINVAL;
1986 if (retval < 0) 1986 if (retval < 0)
1987 goto out_free; 1987 goto out_free;
1988 bprm->argc = retval; 1988 bprm->argc = retval;
1989 1989
1990 retval = count_strings_kernel(envp); 1990 retval = count_strings_kernel(envp);
1991 if (retval < 0) 1991 if (retval < 0)
1992 goto out_free; 1992 goto out_free;
1993 bprm->envc = retval; 1993 bprm->envc = retval;
1994 1994
1995 retval = bprm_stack_limits(bprm); 1995 retval = bprm_stack_limits(bprm);
1996 if (retval < 0) 1996 if (retval < 0)
1997 goto out_free; 1997 goto out_free;
1998 1998
1999 retval = copy_string_kernel(bprm->fil 1999 retval = copy_string_kernel(bprm->filename, bprm);
2000 if (retval < 0) 2000 if (retval < 0)
2001 goto out_free; 2001 goto out_free;
2002 bprm->exec = bprm->p; 2002 bprm->exec = bprm->p;
2003 2003
2004 retval = copy_strings_kernel(bprm->en 2004 retval = copy_strings_kernel(bprm->envc, envp, bprm);
2005 if (retval < 0) 2005 if (retval < 0)
2006 goto out_free; 2006 goto out_free;
2007 2007
2008 retval = copy_strings_kernel(bprm->ar 2008 retval = copy_strings_kernel(bprm->argc, argv, bprm);
2009 if (retval < 0) 2009 if (retval < 0)
2010 goto out_free; 2010 goto out_free;
2011 2011
2012 retval = bprm_execve(bprm); 2012 retval = bprm_execve(bprm);
2013 out_free: 2013 out_free:
2014 free_bprm(bprm); 2014 free_bprm(bprm);
2015 out_ret: 2015 out_ret:
2016 putname(filename); 2016 putname(filename);
2017 return retval; 2017 return retval;
2018 } 2018 }
2019 2019
2020 static int do_execve(struct filename *filenam 2020 static int do_execve(struct filename *filename,
2021 const char __user *const __user *__ar 2021 const char __user *const __user *__argv,
2022 const char __user *const __user *__en 2022 const char __user *const __user *__envp)
2023 { 2023 {
2024 struct user_arg_ptr argv = { .ptr.nat 2024 struct user_arg_ptr argv = { .ptr.native = __argv };
2025 struct user_arg_ptr envp = { .ptr.nat 2025 struct user_arg_ptr envp = { .ptr.native = __envp };
2026 return do_execveat_common(AT_FDCWD, f 2026 return do_execveat_common(AT_FDCWD, filename, argv, envp, 0);
2027 } 2027 }
2028 2028
2029 static int do_execveat(int fd, struct filenam 2029 static int do_execveat(int fd, struct filename *filename,
2030 const char __user *const __us 2030 const char __user *const __user *__argv,
2031 const char __user *const __us 2031 const char __user *const __user *__envp,
2032 int flags) 2032 int flags)
2033 { 2033 {
2034 struct user_arg_ptr argv = { .ptr.nat 2034 struct user_arg_ptr argv = { .ptr.native = __argv };
2035 struct user_arg_ptr envp = { .ptr.nat 2035 struct user_arg_ptr envp = { .ptr.native = __envp };
2036 2036
2037 return do_execveat_common(fd, filenam 2037 return do_execveat_common(fd, filename, argv, envp, flags);
2038 } 2038 }
2039 2039
2040 #ifdef CONFIG_COMPAT 2040 #ifdef CONFIG_COMPAT
2041 static int compat_do_execve(struct filename * 2041 static int compat_do_execve(struct filename *filename,
2042 const compat_uptr_t __user *__argv, 2042 const compat_uptr_t __user *__argv,
2043 const compat_uptr_t __user *__envp) 2043 const compat_uptr_t __user *__envp)
2044 { 2044 {
2045 struct user_arg_ptr argv = { 2045 struct user_arg_ptr argv = {
2046 .is_compat = true, 2046 .is_compat = true,
2047 .ptr.compat = __argv, 2047 .ptr.compat = __argv,
2048 }; 2048 };
2049 struct user_arg_ptr envp = { 2049 struct user_arg_ptr envp = {
2050 .is_compat = true, 2050 .is_compat = true,
2051 .ptr.compat = __envp, 2051 .ptr.compat = __envp,
2052 }; 2052 };
2053 return do_execveat_common(AT_FDCWD, f 2053 return do_execveat_common(AT_FDCWD, filename, argv, envp, 0);
2054 } 2054 }
2055 2055
2056 static int compat_do_execveat(int fd, struct 2056 static int compat_do_execveat(int fd, struct filename *filename,
2057 const compat_up 2057 const compat_uptr_t __user *__argv,
2058 const compat_up 2058 const compat_uptr_t __user *__envp,
2059 int flags) 2059 int flags)
2060 { 2060 {
2061 struct user_arg_ptr argv = { 2061 struct user_arg_ptr argv = {
2062 .is_compat = true, 2062 .is_compat = true,
2063 .ptr.compat = __argv, 2063 .ptr.compat = __argv,
2064 }; 2064 };
2065 struct user_arg_ptr envp = { 2065 struct user_arg_ptr envp = {
2066 .is_compat = true, 2066 .is_compat = true,
2067 .ptr.compat = __envp, 2067 .ptr.compat = __envp,
2068 }; 2068 };
2069 return do_execveat_common(fd, filenam 2069 return do_execveat_common(fd, filename, argv, envp, flags);
2070 } 2070 }
2071 #endif 2071 #endif
2072 2072
2073 void set_binfmt(struct linux_binfmt *new) 2073 void set_binfmt(struct linux_binfmt *new)
2074 { 2074 {
2075 struct mm_struct *mm = current->mm; 2075 struct mm_struct *mm = current->mm;
2076 2076
2077 if (mm->binfmt) 2077 if (mm->binfmt)
2078 module_put(mm->binfmt->module 2078 module_put(mm->binfmt->module);
2079 2079
2080 mm->binfmt = new; 2080 mm->binfmt = new;
2081 if (new) 2081 if (new)
2082 __module_get(new->module); 2082 __module_get(new->module);
2083 } 2083 }
2084 EXPORT_SYMBOL(set_binfmt); 2084 EXPORT_SYMBOL(set_binfmt);
2085 2085
2086 /* 2086 /*
2087 * set_dumpable stores three-value SUID_DUMP_ 2087 * set_dumpable stores three-value SUID_DUMP_* into mm->flags.
2088 */ 2088 */
2089 void set_dumpable(struct mm_struct *mm, int v 2089 void set_dumpable(struct mm_struct *mm, int value)
2090 { 2090 {
2091 if (WARN_ON((unsigned)value > SUID_DU 2091 if (WARN_ON((unsigned)value > SUID_DUMP_ROOT))
2092 return; 2092 return;
2093 2093
2094 set_mask_bits(&mm->flags, MMF_DUMPABL 2094 set_mask_bits(&mm->flags, MMF_DUMPABLE_MASK, value);
2095 } 2095 }
2096 2096
2097 SYSCALL_DEFINE3(execve, 2097 SYSCALL_DEFINE3(execve,
2098 const char __user *, filename 2098 const char __user *, filename,
2099 const char __user *const __us 2099 const char __user *const __user *, argv,
2100 const char __user *const __us 2100 const char __user *const __user *, envp)
2101 { 2101 {
2102 return do_execve(getname(filename), a 2102 return do_execve(getname(filename), argv, envp);
2103 } 2103 }
2104 2104
2105 SYSCALL_DEFINE5(execveat, 2105 SYSCALL_DEFINE5(execveat,
2106 int, fd, const char __user *, 2106 int, fd, const char __user *, filename,
2107 const char __user *const __us 2107 const char __user *const __user *, argv,
2108 const char __user *const __us 2108 const char __user *const __user *, envp,
2109 int, flags) 2109 int, flags)
2110 { 2110 {
2111 return do_execveat(fd, 2111 return do_execveat(fd,
2112 getname_uflags(fil 2112 getname_uflags(filename, flags),
2113 argv, envp, flags) 2113 argv, envp, flags);
2114 } 2114 }
2115 2115
2116 #ifdef CONFIG_COMPAT 2116 #ifdef CONFIG_COMPAT
2117 COMPAT_SYSCALL_DEFINE3(execve, const char __u 2117 COMPAT_SYSCALL_DEFINE3(execve, const char __user *, filename,
2118 const compat_uptr_t __user *, argv, 2118 const compat_uptr_t __user *, argv,
2119 const compat_uptr_t __user *, envp) 2119 const compat_uptr_t __user *, envp)
2120 { 2120 {
2121 return compat_do_execve(getname(filen 2121 return compat_do_execve(getname(filename), argv, envp);
2122 } 2122 }
2123 2123
2124 COMPAT_SYSCALL_DEFINE5(execveat, int, fd, 2124 COMPAT_SYSCALL_DEFINE5(execveat, int, fd,
2125 const char __user *, f 2125 const char __user *, filename,
2126 const compat_uptr_t __ 2126 const compat_uptr_t __user *, argv,
2127 const compat_uptr_t __ 2127 const compat_uptr_t __user *, envp,
2128 int, flags) 2128 int, flags)
2129 { 2129 {
2130 return compat_do_execveat(fd, 2130 return compat_do_execveat(fd,
2131 getname_ufl 2131 getname_uflags(filename, flags),
2132 argv, envp, 2132 argv, envp, flags);
2133 } 2133 }
2134 #endif 2134 #endif
2135 2135
2136 #ifdef CONFIG_SYSCTL 2136 #ifdef CONFIG_SYSCTL
2137 2137
2138 static int proc_dointvec_minmax_coredump(cons 2138 static int proc_dointvec_minmax_coredump(const struct ctl_table *table, int write,
2139 void *buffer, size_t *lenp, l 2139 void *buffer, size_t *lenp, loff_t *ppos)
2140 { 2140 {
2141 int error = proc_dointvec_minmax(tabl 2141 int error = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
2142 2142
2143 if (!error) 2143 if (!error)
2144 validate_coredump_safety(); 2144 validate_coredump_safety();
2145 return error; 2145 return error;
2146 } 2146 }
2147 2147
2148 static struct ctl_table fs_exec_sysctls[] = { 2148 static struct ctl_table fs_exec_sysctls[] = {
2149 { 2149 {
2150 .procname = "suid_dumpa 2150 .procname = "suid_dumpable",
2151 .data = &suid_dumpa 2151 .data = &suid_dumpable,
2152 .maxlen = sizeof(int) 2152 .maxlen = sizeof(int),
2153 .mode = 0644, 2153 .mode = 0644,
2154 .proc_handler = proc_dointv 2154 .proc_handler = proc_dointvec_minmax_coredump,
2155 .extra1 = SYSCTL_ZERO 2155 .extra1 = SYSCTL_ZERO,
2156 .extra2 = SYSCTL_TWO, 2156 .extra2 = SYSCTL_TWO,
2157 }, 2157 },
2158 }; 2158 };
2159 2159
2160 static int __init init_fs_exec_sysctls(void) 2160 static int __init init_fs_exec_sysctls(void)
2161 { 2161 {
2162 register_sysctl_init("fs", fs_exec_sy 2162 register_sysctl_init("fs", fs_exec_sysctls);
2163 return 0; 2163 return 0;
2164 } 2164 }
2165 2165
2166 fs_initcall(init_fs_exec_sysctls); 2166 fs_initcall(init_fs_exec_sysctls);
2167 #endif /* CONFIG_SYSCTL */ 2167 #endif /* CONFIG_SYSCTL */
2168 2168
2169 #ifdef CONFIG_EXEC_KUNIT_TEST 2169 #ifdef CONFIG_EXEC_KUNIT_TEST
2170 #include "tests/exec_kunit.c" 2170 #include "tests/exec_kunit.c"
2171 #endif 2171 #endif
2172 2172
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