1 // SPDX-License-Identifier: GPL-2.0
2 #define _GNU_SOURCE
3 #define __EXPORTED_HEADERS__
4
5 #include <errno.h>
6 #include <inttypes.h>
7 #include <limits.h>
8 #include <linux/falloc.h>
9 #include <fcntl.h>
10 #include <linux/memfd.h>
11 #include <sched.h>
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <signal.h>
15 #include <string.h>
16 #include <sys/mman.h>
17 #include <sys/stat.h>
18 #include <sys/syscall.h>
19 #include <sys/wait.h>
20 #include <unistd.h>
21 #include <ctype.h>
22
23 #include "common.h"
24
25 #define MEMFD_STR "memfd:"
26 #define MEMFD_HUGE_STR "memfd-hugetlb:"
27 #define SHARED_FT_STR "(shared file-table)"
28
29 #define MFD_DEF_SIZE 8192
30 #define STACK_SIZE 65536
31
32 #define F_SEAL_EXEC 0x0020
33
34 #define F_WX_SEALS (F_SEAL_SHRINK | \
35 F_SEAL_GROW | \
36 F_SEAL_WRITE | \
37 F_SEAL_FUTURE_WRITE | \
38 F_SEAL_EXEC)
39
40 #define MFD_NOEXEC_SEAL 0x0008U
41
42 /*
43 * Default is not to test hugetlbfs
44 */
45 static size_t mfd_def_size = MFD_DEF_SIZE;
46 static const char *memfd_str = MEMFD_STR;
47
48 static ssize_t fd2name(int fd, char *buf, size_t bufsize)
49 {
50 char buf1[PATH_MAX];
51 int size;
52 ssize_t nbytes;
53
54 size = snprintf(buf1, PATH_MAX, "/proc/self/fd/%d", fd);
55 if (size < 0) {
56 printf("snprintf(%d) failed on %m\n", fd);
57 abort();
58 }
59
60 /*
61 * reserver one byte for string termination.
62 */
63 nbytes = readlink(buf1, buf, bufsize-1);
64 if (nbytes == -1) {
65 printf("readlink(%s) failed %m\n", buf1);
66 abort();
67 }
68 buf[nbytes] = '\0';
69 return nbytes;
70 }
71
72 static int mfd_assert_new(const char *name, loff_t sz, unsigned int flags)
73 {
74 int r, fd;
75
76 fd = sys_memfd_create(name, flags);
77 if (fd < 0) {
78 printf("memfd_create(\"%s\", %u) failed: %m\n",
79 name, flags);
80 abort();
81 }
82
83 r = ftruncate(fd, sz);
84 if (r < 0) {
85 printf("ftruncate(%llu) failed: %m\n", (unsigned long long)sz);
86 abort();
87 }
88
89 return fd;
90 }
91
92 static void sysctl_assert_write(const char *val)
93 {
94 int fd = open("/proc/sys/vm/memfd_noexec", O_WRONLY | O_CLOEXEC);
95
96 if (fd < 0) {
97 printf("open sysctl failed: %m\n");
98 abort();
99 }
100
101 if (write(fd, val, strlen(val)) < 0) {
102 printf("write sysctl %s failed: %m\n", val);
103 abort();
104 }
105 }
106
107 static void sysctl_fail_write(const char *val)
108 {
109 int fd = open("/proc/sys/vm/memfd_noexec", O_WRONLY | O_CLOEXEC);
110
111 if (fd < 0) {
112 printf("open sysctl failed: %m\n");
113 abort();
114 }
115
116 if (write(fd, val, strlen(val)) >= 0) {
117 printf("write sysctl %s succeeded, but failure expected\n",
118 val);
119 abort();
120 }
121 }
122
123 static void sysctl_assert_equal(const char *val)
124 {
125 char *p, buf[128] = {};
126 int fd = open("/proc/sys/vm/memfd_noexec", O_RDONLY | O_CLOEXEC);
127
128 if (fd < 0) {
129 printf("open sysctl failed: %m\n");
130 abort();
131 }
132
133 if (read(fd, buf, sizeof(buf)) < 0) {
134 printf("read sysctl failed: %m\n");
135 abort();
136 }
137
138 /* Strip trailing whitespace. */
139 p = buf;
140 while (!isspace(*p))
141 p++;
142 *p = '\0';
143
144 if (strcmp(buf, val) != 0) {
145 printf("unexpected sysctl value: expected %s, got %s\n", val, buf);
146 abort();
147 }
148 }
149
150 static int mfd_assert_reopen_fd(int fd_in)
151 {
152 int fd;
153 char path[100];
154
155 sprintf(path, "/proc/self/fd/%d", fd_in);
156
157 fd = open(path, O_RDWR);
158 if (fd < 0) {
159 printf("re-open of existing fd %d failed\n", fd_in);
160 abort();
161 }
162
163 return fd;
164 }
165
166 static void mfd_fail_new(const char *name, unsigned int flags)
167 {
168 int r;
169
170 r = sys_memfd_create(name, flags);
171 if (r >= 0) {
172 printf("memfd_create(\"%s\", %u) succeeded, but failure expected\n",
173 name, flags);
174 close(r);
175 abort();
176 }
177 }
178
179 static unsigned int mfd_assert_get_seals(int fd)
180 {
181 int r;
182
183 r = fcntl(fd, F_GET_SEALS);
184 if (r < 0) {
185 printf("GET_SEALS(%d) failed: %m\n", fd);
186 abort();
187 }
188
189 return (unsigned int)r;
190 }
191
192 static void mfd_assert_has_seals(int fd, unsigned int seals)
193 {
194 char buf[PATH_MAX];
195 unsigned int s;
196 fd2name(fd, buf, PATH_MAX);
197
198 s = mfd_assert_get_seals(fd);
199 if (s != seals) {
200 printf("%u != %u = GET_SEALS(%s)\n", seals, s, buf);
201 abort();
202 }
203 }
204
205 static void mfd_assert_add_seals(int fd, unsigned int seals)
206 {
207 int r;
208 unsigned int s;
209
210 s = mfd_assert_get_seals(fd);
211 r = fcntl(fd, F_ADD_SEALS, seals);
212 if (r < 0) {
213 printf("ADD_SEALS(%d, %u -> %u) failed: %m\n", fd, s, seals);
214 abort();
215 }
216 }
217
218 static void mfd_fail_add_seals(int fd, unsigned int seals)
219 {
220 int r;
221 unsigned int s;
222
223 r = fcntl(fd, F_GET_SEALS);
224 if (r < 0)
225 s = 0;
226 else
227 s = (unsigned int)r;
228
229 r = fcntl(fd, F_ADD_SEALS, seals);
230 if (r >= 0) {
231 printf("ADD_SEALS(%d, %u -> %u) didn't fail as expected\n",
232 fd, s, seals);
233 abort();
234 }
235 }
236
237 static void mfd_assert_size(int fd, size_t size)
238 {
239 struct stat st;
240 int r;
241
242 r = fstat(fd, &st);
243 if (r < 0) {
244 printf("fstat(%d) failed: %m\n", fd);
245 abort();
246 } else if (st.st_size != size) {
247 printf("wrong file size %lld, but expected %lld\n",
248 (long long)st.st_size, (long long)size);
249 abort();
250 }
251 }
252
253 static int mfd_assert_dup(int fd)
254 {
255 int r;
256
257 r = dup(fd);
258 if (r < 0) {
259 printf("dup(%d) failed: %m\n", fd);
260 abort();
261 }
262
263 return r;
264 }
265
266 static void *mfd_assert_mmap_shared(int fd)
267 {
268 void *p;
269
270 p = mmap(NULL,
271 mfd_def_size,
272 PROT_READ | PROT_WRITE,
273 MAP_SHARED,
274 fd,
275 0);
276 if (p == MAP_FAILED) {
277 printf("mmap() failed: %m\n");
278 abort();
279 }
280
281 return p;
282 }
283
284 static void *mfd_assert_mmap_private(int fd)
285 {
286 void *p;
287
288 p = mmap(NULL,
289 mfd_def_size,
290 PROT_READ,
291 MAP_PRIVATE,
292 fd,
293 0);
294 if (p == MAP_FAILED) {
295 printf("mmap() failed: %m\n");
296 abort();
297 }
298
299 return p;
300 }
301
302 static int mfd_assert_open(int fd, int flags, mode_t mode)
303 {
304 char buf[512];
305 int r;
306
307 sprintf(buf, "/proc/self/fd/%d", fd);
308 r = open(buf, flags, mode);
309 if (r < 0) {
310 printf("open(%s) failed: %m\n", buf);
311 abort();
312 }
313
314 return r;
315 }
316
317 static void mfd_fail_open(int fd, int flags, mode_t mode)
318 {
319 char buf[512];
320 int r;
321
322 sprintf(buf, "/proc/self/fd/%d", fd);
323 r = open(buf, flags, mode);
324 if (r >= 0) {
325 printf("open(%s) didn't fail as expected\n", buf);
326 abort();
327 }
328 }
329
330 static void mfd_assert_read(int fd)
331 {
332 char buf[16];
333 void *p;
334 ssize_t l;
335
336 l = read(fd, buf, sizeof(buf));
337 if (l != sizeof(buf)) {
338 printf("read() failed: %m\n");
339 abort();
340 }
341
342 /* verify PROT_READ *is* allowed */
343 p = mmap(NULL,
344 mfd_def_size,
345 PROT_READ,
346 MAP_PRIVATE,
347 fd,
348 0);
349 if (p == MAP_FAILED) {
350 printf("mmap() failed: %m\n");
351 abort();
352 }
353 munmap(p, mfd_def_size);
354
355 /* verify MAP_PRIVATE is *always* allowed (even writable) */
356 p = mmap(NULL,
357 mfd_def_size,
358 PROT_READ | PROT_WRITE,
359 MAP_PRIVATE,
360 fd,
361 0);
362 if (p == MAP_FAILED) {
363 printf("mmap() failed: %m\n");
364 abort();
365 }
366 munmap(p, mfd_def_size);
367 }
368
369 /* Test that PROT_READ + MAP_SHARED mappings work. */
370 static void mfd_assert_read_shared(int fd)
371 {
372 void *p;
373
374 /* verify PROT_READ and MAP_SHARED *is* allowed */
375 p = mmap(NULL,
376 mfd_def_size,
377 PROT_READ,
378 MAP_SHARED,
379 fd,
380 0);
381 if (p == MAP_FAILED) {
382 printf("mmap() failed: %m\n");
383 abort();
384 }
385 munmap(p, mfd_def_size);
386 }
387
388 static void mfd_assert_fork_private_write(int fd)
389 {
390 int *p;
391 pid_t pid;
392
393 p = mmap(NULL,
394 mfd_def_size,
395 PROT_READ | PROT_WRITE,
396 MAP_PRIVATE,
397 fd,
398 0);
399 if (p == MAP_FAILED) {
400 printf("mmap() failed: %m\n");
401 abort();
402 }
403
404 p[0] = 22;
405
406 pid = fork();
407 if (pid == 0) {
408 p[0] = 33;
409 exit(0);
410 } else {
411 waitpid(pid, NULL, 0);
412
413 if (p[0] != 22) {
414 printf("MAP_PRIVATE copy-on-write failed: %m\n");
415 abort();
416 }
417 }
418
419 munmap(p, mfd_def_size);
420 }
421
422 static void mfd_assert_write(int fd)
423 {
424 ssize_t l;
425 void *p;
426 int r;
427
428 /*
429 * huegtlbfs does not support write, but we want to
430 * verify everything else here.
431 */
432 if (!hugetlbfs_test) {
433 /* verify write() succeeds */
434 l = write(fd, "\0\0\0\0", 4);
435 if (l != 4) {
436 printf("write() failed: %m\n");
437 abort();
438 }
439 }
440
441 /* verify PROT_READ | PROT_WRITE is allowed */
442 p = mmap(NULL,
443 mfd_def_size,
444 PROT_READ | PROT_WRITE,
445 MAP_SHARED,
446 fd,
447 0);
448 if (p == MAP_FAILED) {
449 printf("mmap() failed: %m\n");
450 abort();
451 }
452 *(char *)p = 0;
453 munmap(p, mfd_def_size);
454
455 /* verify PROT_WRITE is allowed */
456 p = mmap(NULL,
457 mfd_def_size,
458 PROT_WRITE,
459 MAP_SHARED,
460 fd,
461 0);
462 if (p == MAP_FAILED) {
463 printf("mmap() failed: %m\n");
464 abort();
465 }
466 *(char *)p = 0;
467 munmap(p, mfd_def_size);
468
469 /* verify PROT_READ with MAP_SHARED is allowed and a following
470 * mprotect(PROT_WRITE) allows writing */
471 p = mmap(NULL,
472 mfd_def_size,
473 PROT_READ,
474 MAP_SHARED,
475 fd,
476 0);
477 if (p == MAP_FAILED) {
478 printf("mmap() failed: %m\n");
479 abort();
480 }
481
482 r = mprotect(p, mfd_def_size, PROT_READ | PROT_WRITE);
483 if (r < 0) {
484 printf("mprotect() failed: %m\n");
485 abort();
486 }
487
488 *(char *)p = 0;
489 munmap(p, mfd_def_size);
490
491 /* verify PUNCH_HOLE works */
492 r = fallocate(fd,
493 FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
494 0,
495 mfd_def_size);
496 if (r < 0) {
497 printf("fallocate(PUNCH_HOLE) failed: %m\n");
498 abort();
499 }
500 }
501
502 static void mfd_fail_write(int fd)
503 {
504 ssize_t l;
505 void *p;
506 int r;
507
508 /* verify write() fails */
509 l = write(fd, "data", 4);
510 if (l != -EPERM) {
511 printf("expected EPERM on write(), but got %d: %m\n", (int)l);
512 abort();
513 }
514
515 /* verify PROT_READ | PROT_WRITE is not allowed */
516 p = mmap(NULL,
517 mfd_def_size,
518 PROT_READ | PROT_WRITE,
519 MAP_SHARED,
520 fd,
521 0);
522 if (p != MAP_FAILED) {
523 printf("mmap() didn't fail as expected\n");
524 abort();
525 }
526
527 /* verify PROT_WRITE is not allowed */
528 p = mmap(NULL,
529 mfd_def_size,
530 PROT_WRITE,
531 MAP_SHARED,
532 fd,
533 0);
534 if (p != MAP_FAILED) {
535 printf("mmap() didn't fail as expected\n");
536 abort();
537 }
538
539 /* Verify PROT_READ with MAP_SHARED with a following mprotect is not
540 * allowed. Note that for r/w the kernel already prevents the mmap. */
541 p = mmap(NULL,
542 mfd_def_size,
543 PROT_READ,
544 MAP_SHARED,
545 fd,
546 0);
547 if (p != MAP_FAILED) {
548 r = mprotect(p, mfd_def_size, PROT_READ | PROT_WRITE);
549 if (r >= 0) {
550 printf("mmap()+mprotect() didn't fail as expected\n");
551 abort();
552 }
553 munmap(p, mfd_def_size);
554 }
555
556 /* verify PUNCH_HOLE fails */
557 r = fallocate(fd,
558 FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
559 0,
560 mfd_def_size);
561 if (r >= 0) {
562 printf("fallocate(PUNCH_HOLE) didn't fail as expected\n");
563 abort();
564 }
565 }
566
567 static void mfd_assert_shrink(int fd)
568 {
569 int r, fd2;
570
571 r = ftruncate(fd, mfd_def_size / 2);
572 if (r < 0) {
573 printf("ftruncate(SHRINK) failed: %m\n");
574 abort();
575 }
576
577 mfd_assert_size(fd, mfd_def_size / 2);
578
579 fd2 = mfd_assert_open(fd,
580 O_RDWR | O_CREAT | O_TRUNC,
581 S_IRUSR | S_IWUSR);
582 close(fd2);
583
584 mfd_assert_size(fd, 0);
585 }
586
587 static void mfd_fail_shrink(int fd)
588 {
589 int r;
590
591 r = ftruncate(fd, mfd_def_size / 2);
592 if (r >= 0) {
593 printf("ftruncate(SHRINK) didn't fail as expected\n");
594 abort();
595 }
596
597 mfd_fail_open(fd,
598 O_RDWR | O_CREAT | O_TRUNC,
599 S_IRUSR | S_IWUSR);
600 }
601
602 static void mfd_assert_grow(int fd)
603 {
604 int r;
605
606 r = ftruncate(fd, mfd_def_size * 2);
607 if (r < 0) {
608 printf("ftruncate(GROW) failed: %m\n");
609 abort();
610 }
611
612 mfd_assert_size(fd, mfd_def_size * 2);
613
614 r = fallocate(fd,
615 0,
616 0,
617 mfd_def_size * 4);
618 if (r < 0) {
619 printf("fallocate(ALLOC) failed: %m\n");
620 abort();
621 }
622
623 mfd_assert_size(fd, mfd_def_size * 4);
624 }
625
626 static void mfd_fail_grow(int fd)
627 {
628 int r;
629
630 r = ftruncate(fd, mfd_def_size * 2);
631 if (r >= 0) {
632 printf("ftruncate(GROW) didn't fail as expected\n");
633 abort();
634 }
635
636 r = fallocate(fd,
637 0,
638 0,
639 mfd_def_size * 4);
640 if (r >= 0) {
641 printf("fallocate(ALLOC) didn't fail as expected\n");
642 abort();
643 }
644 }
645
646 static void mfd_assert_grow_write(int fd)
647 {
648 static char *buf;
649 ssize_t l;
650
651 /* hugetlbfs does not support write */
652 if (hugetlbfs_test)
653 return;
654
655 buf = malloc(mfd_def_size * 8);
656 if (!buf) {
657 printf("malloc(%zu) failed: %m\n", mfd_def_size * 8);
658 abort();
659 }
660
661 l = pwrite(fd, buf, mfd_def_size * 8, 0);
662 if (l != (mfd_def_size * 8)) {
663 printf("pwrite() failed: %m\n");
664 abort();
665 }
666
667 mfd_assert_size(fd, mfd_def_size * 8);
668 }
669
670 static void mfd_fail_grow_write(int fd)
671 {
672 static char *buf;
673 ssize_t l;
674
675 /* hugetlbfs does not support write */
676 if (hugetlbfs_test)
677 return;
678
679 buf = malloc(mfd_def_size * 8);
680 if (!buf) {
681 printf("malloc(%zu) failed: %m\n", mfd_def_size * 8);
682 abort();
683 }
684
685 l = pwrite(fd, buf, mfd_def_size * 8, 0);
686 if (l == (mfd_def_size * 8)) {
687 printf("pwrite() didn't fail as expected\n");
688 abort();
689 }
690 }
691
692 static void mfd_assert_mode(int fd, int mode)
693 {
694 struct stat st;
695 char buf[PATH_MAX];
696
697 fd2name(fd, buf, PATH_MAX);
698
699 if (fstat(fd, &st) < 0) {
700 printf("fstat(%s) failed: %m\n", buf);
701 abort();
702 }
703
704 if ((st.st_mode & 07777) != mode) {
705 printf("fstat(%s) wrong file mode 0%04o, but expected 0%04o\n",
706 buf, (int)st.st_mode & 07777, mode);
707 abort();
708 }
709 }
710
711 static void mfd_assert_chmod(int fd, int mode)
712 {
713 char buf[PATH_MAX];
714
715 fd2name(fd, buf, PATH_MAX);
716
717 if (fchmod(fd, mode) < 0) {
718 printf("fchmod(%s, 0%04o) failed: %m\n", buf, mode);
719 abort();
720 }
721
722 mfd_assert_mode(fd, mode);
723 }
724
725 static void mfd_fail_chmod(int fd, int mode)
726 {
727 struct stat st;
728 char buf[PATH_MAX];
729
730 fd2name(fd, buf, PATH_MAX);
731
732 if (fstat(fd, &st) < 0) {
733 printf("fstat(%s) failed: %m\n", buf);
734 abort();
735 }
736
737 if (fchmod(fd, mode) == 0) {
738 printf("fchmod(%s, 0%04o) didn't fail as expected\n",
739 buf, mode);
740 abort();
741 }
742
743 /* verify that file mode bits did not change */
744 mfd_assert_mode(fd, st.st_mode & 07777);
745 }
746
747 static int idle_thread_fn(void *arg)
748 {
749 sigset_t set;
750 int sig;
751
752 /* dummy waiter; SIGTERM terminates us anyway */
753 sigemptyset(&set);
754 sigaddset(&set, SIGTERM);
755 sigwait(&set, &sig);
756
757 return 0;
758 }
759
760 static pid_t spawn_thread(unsigned int flags, int (*fn)(void *), void *arg)
761 {
762 uint8_t *stack;
763 pid_t pid;
764
765 stack = malloc(STACK_SIZE);
766 if (!stack) {
767 printf("malloc(STACK_SIZE) failed: %m\n");
768 abort();
769 }
770
771 pid = clone(fn, stack + STACK_SIZE, SIGCHLD | flags, arg);
772 if (pid < 0) {
773 printf("clone() failed: %m\n");
774 abort();
775 }
776
777 return pid;
778 }
779
780 static void join_thread(pid_t pid)
781 {
782 int wstatus;
783
784 if (waitpid(pid, &wstatus, 0) < 0) {
785 printf("newpid thread: waitpid() failed: %m\n");
786 abort();
787 }
788
789 if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) != 0) {
790 printf("newpid thread: exited with non-zero error code %d\n",
791 WEXITSTATUS(wstatus));
792 abort();
793 }
794
795 if (WIFSIGNALED(wstatus)) {
796 printf("newpid thread: killed by signal %d\n",
797 WTERMSIG(wstatus));
798 abort();
799 }
800 }
801
802 static pid_t spawn_idle_thread(unsigned int flags)
803 {
804 return spawn_thread(flags, idle_thread_fn, NULL);
805 }
806
807 static void join_idle_thread(pid_t pid)
808 {
809 kill(pid, SIGTERM);
810 waitpid(pid, NULL, 0);
811 }
812
813 /*
814 * Test memfd_create() syscall
815 * Verify syscall-argument validation, including name checks, flag validation
816 * and more.
817 */
818 static void test_create(void)
819 {
820 char buf[2048];
821 int fd;
822
823 printf("%s CREATE\n", memfd_str);
824
825 /* test NULL name */
826 mfd_fail_new(NULL, 0);
827
828 /* test over-long name (not zero-terminated) */
829 memset(buf, 0xff, sizeof(buf));
830 mfd_fail_new(buf, 0);
831
832 /* test over-long zero-terminated name */
833 memset(buf, 0xff, sizeof(buf));
834 buf[sizeof(buf) - 1] = 0;
835 mfd_fail_new(buf, 0);
836
837 /* verify "" is a valid name */
838 fd = mfd_assert_new("", 0, 0);
839 close(fd);
840
841 /* verify invalid O_* open flags */
842 mfd_fail_new("", 0x0100);
843 mfd_fail_new("", ~MFD_CLOEXEC);
844 mfd_fail_new("", ~MFD_ALLOW_SEALING);
845 mfd_fail_new("", ~0);
846 mfd_fail_new("", 0x80000000U);
847
848 /* verify EXEC and NOEXEC_SEAL can't both be set */
849 mfd_fail_new("", MFD_EXEC | MFD_NOEXEC_SEAL);
850
851 /* verify MFD_CLOEXEC is allowed */
852 fd = mfd_assert_new("", 0, MFD_CLOEXEC);
853 close(fd);
854
855 /* verify MFD_ALLOW_SEALING is allowed */
856 fd = mfd_assert_new("", 0, MFD_ALLOW_SEALING);
857 close(fd);
858
859 /* verify MFD_ALLOW_SEALING | MFD_CLOEXEC is allowed */
860 fd = mfd_assert_new("", 0, MFD_ALLOW_SEALING | MFD_CLOEXEC);
861 close(fd);
862 }
863
864 /*
865 * Test basic sealing
866 * A very basic sealing test to see whether setting/retrieving seals works.
867 */
868 static void test_basic(void)
869 {
870 int fd;
871
872 printf("%s BASIC\n", memfd_str);
873
874 fd = mfd_assert_new("kern_memfd_basic",
875 mfd_def_size,
876 MFD_CLOEXEC | MFD_ALLOW_SEALING);
877
878 /* add basic seals */
879 mfd_assert_has_seals(fd, 0);
880 mfd_assert_add_seals(fd, F_SEAL_SHRINK |
881 F_SEAL_WRITE);
882 mfd_assert_has_seals(fd, F_SEAL_SHRINK |
883 F_SEAL_WRITE);
884
885 /* add them again */
886 mfd_assert_add_seals(fd, F_SEAL_SHRINK |
887 F_SEAL_WRITE);
888 mfd_assert_has_seals(fd, F_SEAL_SHRINK |
889 F_SEAL_WRITE);
890
891 /* add more seals and seal against sealing */
892 mfd_assert_add_seals(fd, F_SEAL_GROW | F_SEAL_SEAL);
893 mfd_assert_has_seals(fd, F_SEAL_SHRINK |
894 F_SEAL_GROW |
895 F_SEAL_WRITE |
896 F_SEAL_SEAL);
897
898 /* verify that sealing no longer works */
899 mfd_fail_add_seals(fd, F_SEAL_GROW);
900 mfd_fail_add_seals(fd, 0);
901
902 close(fd);
903
904 /* verify sealing does not work without MFD_ALLOW_SEALING */
905 fd = mfd_assert_new("kern_memfd_basic",
906 mfd_def_size,
907 MFD_CLOEXEC);
908 mfd_assert_has_seals(fd, F_SEAL_SEAL);
909 mfd_fail_add_seals(fd, F_SEAL_SHRINK |
910 F_SEAL_GROW |
911 F_SEAL_WRITE);
912 mfd_assert_has_seals(fd, F_SEAL_SEAL);
913 close(fd);
914 }
915
916 /*
917 * Test SEAL_WRITE
918 * Test whether SEAL_WRITE actually prevents modifications.
919 */
920 static void test_seal_write(void)
921 {
922 int fd;
923
924 printf("%s SEAL-WRITE\n", memfd_str);
925
926 fd = mfd_assert_new("kern_memfd_seal_write",
927 mfd_def_size,
928 MFD_CLOEXEC | MFD_ALLOW_SEALING);
929 mfd_assert_has_seals(fd, 0);
930 mfd_assert_add_seals(fd, F_SEAL_WRITE);
931 mfd_assert_has_seals(fd, F_SEAL_WRITE);
932
933 mfd_assert_read(fd);
934 mfd_fail_write(fd);
935 mfd_assert_shrink(fd);
936 mfd_assert_grow(fd);
937 mfd_fail_grow_write(fd);
938
939 close(fd);
940 }
941
942 /*
943 * Test SEAL_FUTURE_WRITE
944 * Test whether SEAL_FUTURE_WRITE actually prevents modifications.
945 */
946 static void test_seal_future_write(void)
947 {
948 int fd, fd2;
949 void *p;
950
951 printf("%s SEAL-FUTURE-WRITE\n", memfd_str);
952
953 fd = mfd_assert_new("kern_memfd_seal_future_write",
954 mfd_def_size,
955 MFD_CLOEXEC | MFD_ALLOW_SEALING);
956
957 p = mfd_assert_mmap_shared(fd);
958
959 mfd_assert_has_seals(fd, 0);
960
961 mfd_assert_add_seals(fd, F_SEAL_FUTURE_WRITE);
962 mfd_assert_has_seals(fd, F_SEAL_FUTURE_WRITE);
963
964 /* read should pass, writes should fail */
965 mfd_assert_read(fd);
966 mfd_assert_read_shared(fd);
967 mfd_fail_write(fd);
968
969 fd2 = mfd_assert_reopen_fd(fd);
970 /* read should pass, writes should still fail */
971 mfd_assert_read(fd2);
972 mfd_assert_read_shared(fd2);
973 mfd_fail_write(fd2);
974
975 mfd_assert_fork_private_write(fd);
976
977 munmap(p, mfd_def_size);
978 close(fd2);
979 close(fd);
980 }
981
982 /*
983 * Test SEAL_SHRINK
984 * Test whether SEAL_SHRINK actually prevents shrinking
985 */
986 static void test_seal_shrink(void)
987 {
988 int fd;
989
990 printf("%s SEAL-SHRINK\n", memfd_str);
991
992 fd = mfd_assert_new("kern_memfd_seal_shrink",
993 mfd_def_size,
994 MFD_CLOEXEC | MFD_ALLOW_SEALING);
995 mfd_assert_has_seals(fd, 0);
996 mfd_assert_add_seals(fd, F_SEAL_SHRINK);
997 mfd_assert_has_seals(fd, F_SEAL_SHRINK);
998
999 mfd_assert_read(fd);
1000 mfd_assert_write(fd);
1001 mfd_fail_shrink(fd);
1002 mfd_assert_grow(fd);
1003 mfd_assert_grow_write(fd);
1004
1005 close(fd);
1006 }
1007
1008 /*
1009 * Test SEAL_GROW
1010 * Test whether SEAL_GROW actually prevents growing
1011 */
1012 static void test_seal_grow(void)
1013 {
1014 int fd;
1015
1016 printf("%s SEAL-GROW\n", memfd_str);
1017
1018 fd = mfd_assert_new("kern_memfd_seal_grow",
1019 mfd_def_size,
1020 MFD_CLOEXEC | MFD_ALLOW_SEALING);
1021 mfd_assert_has_seals(fd, 0);
1022 mfd_assert_add_seals(fd, F_SEAL_GROW);
1023 mfd_assert_has_seals(fd, F_SEAL_GROW);
1024
1025 mfd_assert_read(fd);
1026 mfd_assert_write(fd);
1027 mfd_assert_shrink(fd);
1028 mfd_fail_grow(fd);
1029 mfd_fail_grow_write(fd);
1030
1031 close(fd);
1032 }
1033
1034 /*
1035 * Test SEAL_SHRINK | SEAL_GROW
1036 * Test whether SEAL_SHRINK | SEAL_GROW actually prevents resizing
1037 */
1038 static void test_seal_resize(void)
1039 {
1040 int fd;
1041
1042 printf("%s SEAL-RESIZE\n", memfd_str);
1043
1044 fd = mfd_assert_new("kern_memfd_seal_resize",
1045 mfd_def_size,
1046 MFD_CLOEXEC | MFD_ALLOW_SEALING);
1047 mfd_assert_has_seals(fd, 0);
1048 mfd_assert_add_seals(fd, F_SEAL_SHRINK | F_SEAL_GROW);
1049 mfd_assert_has_seals(fd, F_SEAL_SHRINK | F_SEAL_GROW);
1050
1051 mfd_assert_read(fd);
1052 mfd_assert_write(fd);
1053 mfd_fail_shrink(fd);
1054 mfd_fail_grow(fd);
1055 mfd_fail_grow_write(fd);
1056
1057 close(fd);
1058 }
1059
1060 /*
1061 * Test SEAL_EXEC
1062 * Test fd is created with exec and allow sealing.
1063 * chmod() cannot change x bits after sealing.
1064 */
1065 static void test_exec_seal(void)
1066 {
1067 int fd;
1068
1069 printf("%s SEAL-EXEC\n", memfd_str);
1070
1071 printf("%s Apply SEAL_EXEC\n", memfd_str);
1072 fd = mfd_assert_new("kern_memfd_seal_exec",
1073 mfd_def_size,
1074 MFD_CLOEXEC | MFD_ALLOW_SEALING | MFD_EXEC);
1075
1076 mfd_assert_mode(fd, 0777);
1077 mfd_assert_chmod(fd, 0644);
1078
1079 mfd_assert_has_seals(fd, 0);
1080 mfd_assert_add_seals(fd, F_SEAL_EXEC);
1081 mfd_assert_has_seals(fd, F_SEAL_EXEC);
1082
1083 mfd_assert_chmod(fd, 0600);
1084 mfd_fail_chmod(fd, 0777);
1085 mfd_fail_chmod(fd, 0670);
1086 mfd_fail_chmod(fd, 0605);
1087 mfd_fail_chmod(fd, 0700);
1088 mfd_fail_chmod(fd, 0100);
1089 mfd_assert_chmod(fd, 0666);
1090 mfd_assert_write(fd);
1091 close(fd);
1092
1093 printf("%s Apply ALL_SEALS\n", memfd_str);
1094 fd = mfd_assert_new("kern_memfd_seal_exec",
1095 mfd_def_size,
1096 MFD_CLOEXEC | MFD_ALLOW_SEALING | MFD_EXEC);
1097
1098 mfd_assert_mode(fd, 0777);
1099 mfd_assert_chmod(fd, 0700);
1100
1101 mfd_assert_has_seals(fd, 0);
1102 mfd_assert_add_seals(fd, F_SEAL_EXEC);
1103 mfd_assert_has_seals(fd, F_WX_SEALS);
1104
1105 mfd_fail_chmod(fd, 0711);
1106 mfd_fail_chmod(fd, 0600);
1107 mfd_fail_write(fd);
1108 close(fd);
1109 }
1110
1111 /*
1112 * Test EXEC_NO_SEAL
1113 * Test fd is created with exec and not allow sealing.
1114 */
1115 static void test_exec_no_seal(void)
1116 {
1117 int fd;
1118
1119 printf("%s EXEC_NO_SEAL\n", memfd_str);
1120
1121 /* Create with EXEC but without ALLOW_SEALING */
1122 fd = mfd_assert_new("kern_memfd_exec_no_sealing",
1123 mfd_def_size,
1124 MFD_CLOEXEC | MFD_EXEC);
1125 mfd_assert_mode(fd, 0777);
1126 mfd_assert_has_seals(fd, F_SEAL_SEAL);
1127 mfd_assert_chmod(fd, 0666);
1128 close(fd);
1129 }
1130
1131 /*
1132 * Test memfd_create with MFD_NOEXEC flag
1133 */
1134 static void test_noexec_seal(void)
1135 {
1136 int fd;
1137
1138 printf("%s NOEXEC_SEAL\n", memfd_str);
1139
1140 /* Create with NOEXEC and ALLOW_SEALING */
1141 fd = mfd_assert_new("kern_memfd_noexec",
1142 mfd_def_size,
1143 MFD_CLOEXEC | MFD_ALLOW_SEALING | MFD_NOEXEC_SEAL);
1144 mfd_assert_mode(fd, 0666);
1145 mfd_assert_has_seals(fd, F_SEAL_EXEC);
1146 mfd_fail_chmod(fd, 0777);
1147 close(fd);
1148
1149 /* Create with NOEXEC but without ALLOW_SEALING */
1150 fd = mfd_assert_new("kern_memfd_noexec",
1151 mfd_def_size,
1152 MFD_CLOEXEC | MFD_NOEXEC_SEAL);
1153 mfd_assert_mode(fd, 0666);
1154 mfd_assert_has_seals(fd, F_SEAL_EXEC);
1155 mfd_fail_chmod(fd, 0777);
1156 close(fd);
1157 }
1158
1159 static void test_sysctl_sysctl0(void)
1160 {
1161 int fd;
1162
1163 sysctl_assert_equal("");
1164
1165 fd = mfd_assert_new("kern_memfd_sysctl_0_dfl",
1166 mfd_def_size,
1167 MFD_CLOEXEC | MFD_ALLOW_SEALING);
1168 mfd_assert_mode(fd, 0777);
1169 mfd_assert_has_seals(fd, 0);
1170 mfd_assert_chmod(fd, 0644);
1171 close(fd);
1172 }
1173
1174 static void test_sysctl_set_sysctl0(void)
1175 {
1176 sysctl_assert_write("");
1177 test_sysctl_sysctl0();
1178 }
1179
1180 static void test_sysctl_sysctl1(void)
1181 {
1182 int fd;
1183
1184 sysctl_assert_equal("1");
1185
1186 fd = mfd_assert_new("kern_memfd_sysctl_1_dfl",
1187 mfd_def_size,
1188 MFD_CLOEXEC | MFD_ALLOW_SEALING);
1189 mfd_assert_mode(fd, 0666);
1190 mfd_assert_has_seals(fd, F_SEAL_EXEC);
1191 mfd_fail_chmod(fd, 0777);
1192 close(fd);
1193
1194 fd = mfd_assert_new("kern_memfd_sysctl_1_exec",
1195 mfd_def_size,
1196 MFD_CLOEXEC | MFD_EXEC | MFD_ALLOW_SEALING);
1197 mfd_assert_mode(fd, 0777);
1198 mfd_assert_has_seals(fd, 0);
1199 mfd_assert_chmod(fd, 0644);
1200 close(fd);
1201
1202 fd = mfd_assert_new("kern_memfd_sysctl_1_noexec",
1203 mfd_def_size,
1204 MFD_CLOEXEC | MFD_NOEXEC_SEAL | MFD_ALLOW_SEALING);
1205 mfd_assert_mode(fd, 0666);
1206 mfd_assert_has_seals(fd, F_SEAL_EXEC);
1207 mfd_fail_chmod(fd, 0777);
1208 close(fd);
1209 }
1210
1211 static void test_sysctl_set_sysctl1(void)
1212 {
1213 sysctl_assert_write("1");
1214 test_sysctl_sysctl1();
1215 }
1216
1217 static void test_sysctl_sysctl2(void)
1218 {
1219 int fd;
1220
1221 sysctl_assert_equal("2");
1222
1223 fd = mfd_assert_new("kern_memfd_sysctl_2_dfl",
1224 mfd_def_size,
1225 MFD_CLOEXEC | MFD_ALLOW_SEALING);
1226 mfd_assert_mode(fd, 0666);
1227 mfd_assert_has_seals(fd, F_SEAL_EXEC);
1228 mfd_fail_chmod(fd, 0777);
1229 close(fd);
1230
1231 mfd_fail_new("kern_memfd_sysctl_2_exec",
1232 MFD_CLOEXEC | MFD_EXEC | MFD_ALLOW_SEALING);
1233
1234 fd = mfd_assert_new("kern_memfd_sysctl_2_noexec",
1235 mfd_def_size,
1236 MFD_CLOEXEC | MFD_NOEXEC_SEAL | MFD_ALLOW_SEALING);
1237 mfd_assert_mode(fd, 0666);
1238 mfd_assert_has_seals(fd, F_SEAL_EXEC);
1239 mfd_fail_chmod(fd, 0777);
1240 close(fd);
1241 }
1242
1243 static void test_sysctl_set_sysctl2(void)
1244 {
1245 sysctl_assert_write("2");
1246 test_sysctl_sysctl2();
1247 }
1248
1249 static int sysctl_simple_child(void *arg)
1250 {
1251 printf("%s sysctl 0\n", memfd_str);
1252 test_sysctl_set_sysctl0();
1253
1254 printf("%s sysctl 1\n", memfd_str);
1255 test_sysctl_set_sysctl1();
1256
1257 printf("%s sysctl 0\n", memfd_str);
1258 test_sysctl_set_sysctl0();
1259
1260 printf("%s sysctl 2\n", memfd_str);
1261 test_sysctl_set_sysctl2();
1262
1263 printf("%s sysctl 1\n", memfd_str);
1264 test_sysctl_set_sysctl1();
1265
1266 printf("%s sysctl 0\n", memfd_str);
1267 test_sysctl_set_sysctl0();
1268
1269 return 0;
1270 }
1271
1272 /*
1273 * Test sysctl
1274 * A very basic test to make sure the core sysctl semantics work.
1275 */
1276 static void test_sysctl_simple(void)
1277 {
1278 int pid = spawn_thread(CLONE_NEWPID, sysctl_simple_child, NULL);
1279
1280 join_thread(pid);
1281 }
1282
1283 static int sysctl_nested(void *arg)
1284 {
1285 void (*fn)(void) = arg;
1286
1287 fn();
1288 return 0;
1289 }
1290
1291 static int sysctl_nested_wait(void *arg)
1292 {
1293 /* Wait for a SIGCONT. */
1294 kill(getpid(), SIGSTOP);
1295 return sysctl_nested(arg);
1296 }
1297
1298 static void test_sysctl_sysctl1_failset(void)
1299 {
1300 sysctl_fail_write("");
1301 test_sysctl_sysctl1();
1302 }
1303
1304 static void test_sysctl_sysctl2_failset(void)
1305 {
1306 sysctl_fail_write("1");
1307 test_sysctl_sysctl2();
1308
1309 sysctl_fail_write("");
1310 test_sysctl_sysctl2();
1311 }
1312
1313 static int sysctl_nested_child(void *arg)
1314 {
1315 int pid;
1316
1317 printf("%s nested sysctl 0\n", memfd_str);
1318 sysctl_assert_write("");
1319 /* A further nested pidns works the same. */
1320 pid = spawn_thread(CLONE_NEWPID, sysctl_simple_child, NULL);
1321 join_thread(pid);
1322
1323 printf("%s nested sysctl 1\n", memfd_str);
1324 sysctl_assert_write("1");
1325 /* Child inherits our setting. */
1326 pid = spawn_thread(CLONE_NEWPID, sysctl_nested, test_sysctl_sysctl1);
1327 join_thread(pid);
1328 /* Child cannot raise the setting. */
1329 pid = spawn_thread(CLONE_NEWPID, sysctl_nested,
1330 test_sysctl_sysctl1_failset);
1331 join_thread(pid);
1332 /* Child can lower the setting. */
1333 pid = spawn_thread(CLONE_NEWPID, sysctl_nested,
1334 test_sysctl_set_sysctl2);
1335 join_thread(pid);
1336 /* Child lowering the setting has no effect on our setting. */
1337 test_sysctl_sysctl1();
1338
1339 printf("%s nested sysctl 2\n", memfd_str);
1340 sysctl_assert_write("2");
1341 /* Child inherits our setting. */
1342 pid = spawn_thread(CLONE_NEWPID, sysctl_nested, test_sysctl_sysctl2);
1343 join_thread(pid);
1344 /* Child cannot raise the setting. */
1345 pid = spawn_thread(CLONE_NEWPID, sysctl_nested,
1346 test_sysctl_sysctl2_failset);
1347 join_thread(pid);
1348
1349 /* Verify that the rules are actually inherited after fork. */
1350 printf("%s nested sysctl 0 -> 1 after fork\n", memfd_str);
1351 sysctl_assert_write("");
1352
1353 pid = spawn_thread(CLONE_NEWPID, sysctl_nested_wait,
1354 test_sysctl_sysctl1_failset);
1355 sysctl_assert_write("1");
1356 kill(pid, SIGCONT);
1357 join_thread(pid);
1358
1359 printf("%s nested sysctl 0 -> 2 after fork\n", memfd_str);
1360 sysctl_assert_write("");
1361
1362 pid = spawn_thread(CLONE_NEWPID, sysctl_nested_wait,
1363 test_sysctl_sysctl2_failset);
1364 sysctl_assert_write("2");
1365 kill(pid, SIGCONT);
1366 join_thread(pid);
1367
1368 /*
1369 * Verify that the current effective setting is saved on fork, meaning
1370 * that the parent lowering the sysctl doesn't affect already-forked
1371 * children.
1372 */
1373 printf("%s nested sysctl 2 -> 1 after fork\n", memfd_str);
1374 sysctl_assert_write("2");
1375 pid = spawn_thread(CLONE_NEWPID, sysctl_nested_wait,
1376 test_sysctl_sysctl2);
1377 sysctl_assert_write("1");
1378 kill(pid, SIGCONT);
1379 join_thread(pid);
1380
1381 printf("%s nested sysctl 2 -> 0 after fork\n", memfd_str);
1382 sysctl_assert_write("2");
1383 pid = spawn_thread(CLONE_NEWPID, sysctl_nested_wait,
1384 test_sysctl_sysctl2);
1385 sysctl_assert_write("");
1386 kill(pid, SIGCONT);
1387 join_thread(pid);
1388
1389 printf("%s nested sysctl 1 -> 0 after fork\n", memfd_str);
1390 sysctl_assert_write("1");
1391 pid = spawn_thread(CLONE_NEWPID, sysctl_nested_wait,
1392 test_sysctl_sysctl1);
1393 sysctl_assert_write("");
1394 kill(pid, SIGCONT);
1395 join_thread(pid);
1396
1397 return 0;
1398 }
1399
1400 /*
1401 * Test sysctl with nested pid namespaces
1402 * Make sure that the sysctl nesting semantics work correctly.
1403 */
1404 static void test_sysctl_nested(void)
1405 {
1406 int pid = spawn_thread(CLONE_NEWPID, sysctl_nested_child, NULL);
1407
1408 join_thread(pid);
1409 }
1410
1411 /*
1412 * Test sharing via dup()
1413 * Test that seals are shared between dupped FDs and they're all equal.
1414 */
1415 static void test_share_dup(char *banner, char *b_suffix)
1416 {
1417 int fd, fd2;
1418
1419 printf("%s %s %s\n", memfd_str, banner, b_suffix);
1420
1421 fd = mfd_assert_new("kern_memfd_share_dup",
1422 mfd_def_size,
1423 MFD_CLOEXEC | MFD_ALLOW_SEALING);
1424 mfd_assert_has_seals(fd, 0);
1425
1426 fd2 = mfd_assert_dup(fd);
1427 mfd_assert_has_seals(fd2, 0);
1428
1429 mfd_assert_add_seals(fd, F_SEAL_WRITE);
1430 mfd_assert_has_seals(fd, F_SEAL_WRITE);
1431 mfd_assert_has_seals(fd2, F_SEAL_WRITE);
1432
1433 mfd_assert_add_seals(fd2, F_SEAL_SHRINK);
1434 mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK);
1435 mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK);
1436
1437 mfd_assert_add_seals(fd, F_SEAL_SEAL);
1438 mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL);
1439 mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL);
1440
1441 mfd_fail_add_seals(fd, F_SEAL_GROW);
1442 mfd_fail_add_seals(fd2, F_SEAL_GROW);
1443 mfd_fail_add_seals(fd, F_SEAL_SEAL);
1444 mfd_fail_add_seals(fd2, F_SEAL_SEAL);
1445
1446 close(fd2);
1447
1448 mfd_fail_add_seals(fd, F_SEAL_GROW);
1449 close(fd);
1450 }
1451
1452 /*
1453 * Test sealing with active mmap()s
1454 * Modifying seals is only allowed if no other mmap() refs exist.
1455 */
1456 static void test_share_mmap(char *banner, char *b_suffix)
1457 {
1458 int fd;
1459 void *p;
1460
1461 printf("%s %s %s\n", memfd_str, banner, b_suffix);
1462
1463 fd = mfd_assert_new("kern_memfd_share_mmap",
1464 mfd_def_size,
1465 MFD_CLOEXEC | MFD_ALLOW_SEALING);
1466 mfd_assert_has_seals(fd, 0);
1467
1468 /* shared/writable ref prevents sealing WRITE, but allows others */
1469 p = mfd_assert_mmap_shared(fd);
1470 mfd_fail_add_seals(fd, F_SEAL_WRITE);
1471 mfd_assert_has_seals(fd, 0);
1472 mfd_assert_add_seals(fd, F_SEAL_SHRINK);
1473 mfd_assert_has_seals(fd, F_SEAL_SHRINK);
1474 munmap(p, mfd_def_size);
1475
1476 /* readable ref allows sealing */
1477 p = mfd_assert_mmap_private(fd);
1478 mfd_assert_add_seals(fd, F_SEAL_WRITE);
1479 mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK);
1480 munmap(p, mfd_def_size);
1481
1482 close(fd);
1483 }
1484
1485 /*
1486 * Test sealing with open(/proc/self/fd/%d)
1487 * Via /proc we can get access to a separate file-context for the same memfd.
1488 * This is *not* like dup(), but like a real separate open(). Make sure the
1489 * semantics are as expected and we correctly check for RDONLY / WRONLY / RDWR.
1490 */
1491 static void test_share_open(char *banner, char *b_suffix)
1492 {
1493 int fd, fd2;
1494
1495 printf("%s %s %s\n", memfd_str, banner, b_suffix);
1496
1497 fd = mfd_assert_new("kern_memfd_share_open",
1498 mfd_def_size,
1499 MFD_CLOEXEC | MFD_ALLOW_SEALING);
1500 mfd_assert_has_seals(fd, 0);
1501
1502 fd2 = mfd_assert_open(fd, O_RDWR, 0);
1503 mfd_assert_add_seals(fd, F_SEAL_WRITE);
1504 mfd_assert_has_seals(fd, F_SEAL_WRITE);
1505 mfd_assert_has_seals(fd2, F_SEAL_WRITE);
1506
1507 mfd_assert_add_seals(fd2, F_SEAL_SHRINK);
1508 mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK);
1509 mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK);
1510
1511 close(fd);
1512 fd = mfd_assert_open(fd2, O_RDONLY, 0);
1513
1514 mfd_fail_add_seals(fd, F_SEAL_SEAL);
1515 mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK);
1516 mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK);
1517
1518 close(fd2);
1519 fd2 = mfd_assert_open(fd, O_RDWR, 0);
1520
1521 mfd_assert_add_seals(fd2, F_SEAL_SEAL);
1522 mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL);
1523 mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL);
1524
1525 close(fd2);
1526 close(fd);
1527 }
1528
1529 /*
1530 * Test sharing via fork()
1531 * Test whether seal-modifications work as expected with forked children.
1532 */
1533 static void test_share_fork(char *banner, char *b_suffix)
1534 {
1535 int fd;
1536 pid_t pid;
1537
1538 printf("%s %s %s\n", memfd_str, banner, b_suffix);
1539
1540 fd = mfd_assert_new("kern_memfd_share_fork",
1541 mfd_def_size,
1542 MFD_CLOEXEC | MFD_ALLOW_SEALING);
1543 mfd_assert_has_seals(fd, 0);
1544
1545 pid = spawn_idle_thread(0);
1546 mfd_assert_add_seals(fd, F_SEAL_SEAL);
1547 mfd_assert_has_seals(fd, F_SEAL_SEAL);
1548
1549 mfd_fail_add_seals(fd, F_SEAL_WRITE);
1550 mfd_assert_has_seals(fd, F_SEAL_SEAL);
1551
1552 join_idle_thread(pid);
1553
1554 mfd_fail_add_seals(fd, F_SEAL_WRITE);
1555 mfd_assert_has_seals(fd, F_SEAL_SEAL);
1556
1557 close(fd);
1558 }
1559
1560 int main(int argc, char **argv)
1561 {
1562 pid_t pid;
1563
1564 if (argc == 2) {
1565 if (!strcmp(argv[1], "hugetlbfs")) {
1566 unsigned long hpage_size = default_huge_page_size();
1567
1568 if (!hpage_size) {
1569 printf("Unable to determine huge page size\n");
1570 abort();
1571 }
1572
1573 hugetlbfs_test = 1;
1574 memfd_str = MEMFD_HUGE_STR;
1575 mfd_def_size = hpage_size * 2;
1576 } else {
1577 printf("Unknown option: %s\n", argv[1]);
1578 abort();
1579 }
1580 }
1581
1582 test_create();
1583 test_basic();
1584 test_exec_seal();
1585 test_exec_no_seal();
1586 test_noexec_seal();
1587
1588 test_seal_write();
1589 test_seal_future_write();
1590 test_seal_shrink();
1591 test_seal_grow();
1592 test_seal_resize();
1593
1594 test_sysctl_simple();
1595 test_sysctl_nested();
1596
1597 test_share_dup("SHARE-DUP", "");
1598 test_share_mmap("SHARE-MMAP", "");
1599 test_share_open("SHARE-OPEN", "");
1600 test_share_fork("SHARE-FORK", "");
1601
1602 /* Run test-suite in a multi-threaded environment with a shared
1603 * file-table. */
1604 pid = spawn_idle_thread(CLONE_FILES | CLONE_FS | CLONE_VM);
1605 test_share_dup("SHARE-DUP", SHARED_FT_STR);
1606 test_share_mmap("SHARE-MMAP", SHARED_FT_STR);
1607 test_share_open("SHARE-OPEN", SHARED_FT_STR);
1608 test_share_fork("SHARE-FORK", SHARED_FT_STR);
1609 join_idle_thread(pid);
1610
1611 printf("memfd: DONE\n");
1612
1613 return 0;
1614 }
1615
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