1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/kernel.h>
3 #include <linux/errno.h>
4 #include <linux/fs.h>
5 #include <linux/file.h>
6 #include <linux/mm.h>
7 #include <linux/slab.h>
8 #include <linux/namei.h>
9 #include <linux/io_uring.h>
10 #include <linux/xattr.h>
11
12 #include <uapi/linux/io_uring.h>
13
14 #include "../fs/internal.h"
15
16 #include "io_uring.h"
17 #include "xattr.h"
18
19 struct io_xattr {
20 struct file *file;
21 struct xattr_ctx ctx;
22 struct filename *filename;
23 };
24
25 void io_xattr_cleanup(struct io_kiocb *req)
26 {
27 struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
28
29 if (ix->filename)
30 putname(ix->filename);
31
32 kfree(ix->ctx.kname);
33 kvfree(ix->ctx.kvalue);
34 }
35
36 static void io_xattr_finish(struct io_kiocb *req, int ret)
37 {
38 req->flags &= ~REQ_F_NEED_CLEANUP;
39
40 io_xattr_cleanup(req);
41 io_req_set_res(req, ret, 0);
42 }
43
44 static int __io_getxattr_prep(struct io_kiocb *req,
45 const struct io_uring_sqe *sqe)
46 {
47 struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
48 const char __user *name;
49 int ret;
50
51 if (unlikely(req->flags & REQ_F_FIXED_FILE))
52 return -EBADF;
53
54 ix->filename = NULL;
55 ix->ctx.kvalue = NULL;
56 name = u64_to_user_ptr(READ_ONCE(sqe->addr));
57 ix->ctx.cvalue = u64_to_user_ptr(READ_ONCE(sqe->addr2));
58 ix->ctx.size = READ_ONCE(sqe->len);
59 ix->ctx.flags = READ_ONCE(sqe->xattr_flags);
60
61 if (ix->ctx.flags)
62 return -EINVAL;
63
64 ix->ctx.kname = kmalloc(sizeof(*ix->ctx.kname), GFP_KERNEL);
65 if (!ix->ctx.kname)
66 return -ENOMEM;
67
68 ret = strncpy_from_user(ix->ctx.kname->name, name,
69 sizeof(ix->ctx.kname->name));
70 if (!ret || ret == sizeof(ix->ctx.kname->name))
71 ret = -ERANGE;
72 if (ret < 0) {
73 kfree(ix->ctx.kname);
74 return ret;
75 }
76
77 req->flags |= REQ_F_NEED_CLEANUP;
78 req->flags |= REQ_F_FORCE_ASYNC;
79 return 0;
80 }
81
82 int io_fgetxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
83 {
84 return __io_getxattr_prep(req, sqe);
85 }
86
87 int io_getxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
88 {
89 struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
90 const char __user *path;
91 int ret;
92
93 ret = __io_getxattr_prep(req, sqe);
94 if (ret)
95 return ret;
96
97 path = u64_to_user_ptr(READ_ONCE(sqe->addr3));
98
99 ix->filename = getname_flags(path, LOOKUP_FOLLOW);
100 if (IS_ERR(ix->filename)) {
101 ret = PTR_ERR(ix->filename);
102 ix->filename = NULL;
103 }
104
105 return ret;
106 }
107
108 int io_fgetxattr(struct io_kiocb *req, unsigned int issue_flags)
109 {
110 struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
111 int ret;
112
113 WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
114
115 ret = do_getxattr(file_mnt_idmap(req->file),
116 req->file->f_path.dentry,
117 &ix->ctx);
118
119 io_xattr_finish(req, ret);
120 return IOU_OK;
121 }
122
123 int io_getxattr(struct io_kiocb *req, unsigned int issue_flags)
124 {
125 struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
126 unsigned int lookup_flags = LOOKUP_FOLLOW;
127 struct path path;
128 int ret;
129
130 WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
131
132 retry:
133 ret = filename_lookup(AT_FDCWD, ix->filename, lookup_flags, &path, NULL);
134 if (!ret) {
135 ret = do_getxattr(mnt_idmap(path.mnt), path.dentry, &ix->ctx);
136
137 path_put(&path);
138 if (retry_estale(ret, lookup_flags)) {
139 lookup_flags |= LOOKUP_REVAL;
140 goto retry;
141 }
142 }
143
144 io_xattr_finish(req, ret);
145 return IOU_OK;
146 }
147
148 static int __io_setxattr_prep(struct io_kiocb *req,
149 const struct io_uring_sqe *sqe)
150 {
151 struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
152 const char __user *name;
153 int ret;
154
155 if (unlikely(req->flags & REQ_F_FIXED_FILE))
156 return -EBADF;
157
158 ix->filename = NULL;
159 name = u64_to_user_ptr(READ_ONCE(sqe->addr));
160 ix->ctx.cvalue = u64_to_user_ptr(READ_ONCE(sqe->addr2));
161 ix->ctx.kvalue = NULL;
162 ix->ctx.size = READ_ONCE(sqe->len);
163 ix->ctx.flags = READ_ONCE(sqe->xattr_flags);
164
165 ix->ctx.kname = kmalloc(sizeof(*ix->ctx.kname), GFP_KERNEL);
166 if (!ix->ctx.kname)
167 return -ENOMEM;
168
169 ret = setxattr_copy(name, &ix->ctx);
170 if (ret) {
171 kfree(ix->ctx.kname);
172 return ret;
173 }
174
175 req->flags |= REQ_F_NEED_CLEANUP;
176 req->flags |= REQ_F_FORCE_ASYNC;
177 return 0;
178 }
179
180 int io_setxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
181 {
182 struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
183 const char __user *path;
184 int ret;
185
186 ret = __io_setxattr_prep(req, sqe);
187 if (ret)
188 return ret;
189
190 path = u64_to_user_ptr(READ_ONCE(sqe->addr3));
191
192 ix->filename = getname_flags(path, LOOKUP_FOLLOW);
193 if (IS_ERR(ix->filename)) {
194 ret = PTR_ERR(ix->filename);
195 ix->filename = NULL;
196 }
197
198 return ret;
199 }
200
201 int io_fsetxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
202 {
203 return __io_setxattr_prep(req, sqe);
204 }
205
206 static int __io_setxattr(struct io_kiocb *req, unsigned int issue_flags,
207 const struct path *path)
208 {
209 struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
210 int ret;
211
212 ret = mnt_want_write(path->mnt);
213 if (!ret) {
214 ret = do_setxattr(mnt_idmap(path->mnt), path->dentry, &ix->ctx);
215 mnt_drop_write(path->mnt);
216 }
217
218 return ret;
219 }
220
221 int io_fsetxattr(struct io_kiocb *req, unsigned int issue_flags)
222 {
223 int ret;
224
225 WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
226
227 ret = __io_setxattr(req, issue_flags, &req->file->f_path);
228 io_xattr_finish(req, ret);
229 return IOU_OK;
230 }
231
232 int io_setxattr(struct io_kiocb *req, unsigned int issue_flags)
233 {
234 struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
235 unsigned int lookup_flags = LOOKUP_FOLLOW;
236 struct path path;
237 int ret;
238
239 WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);
240
241 retry:
242 ret = filename_lookup(AT_FDCWD, ix->filename, lookup_flags, &path, NULL);
243 if (!ret) {
244 ret = __io_setxattr(req, issue_flags, &path);
245 path_put(&path);
246 if (retry_estale(ret, lookup_flags)) {
247 lookup_flags |= LOOKUP_REVAL;
248 goto retry;
249 }
250 }
251
252 io_xattr_finish(req, ret);
253 return IOU_OK;
254 }
255
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