| @@ -0,0 +1,913 @@ |
| 1 | +#define _GNU_SOURCE |
| 2 | +#define __EXPORTED_HEADERS__ |
| 3 | + |
| 4 | +#include <errno.h> |
| 5 | +#include <inttypes.h> |
| 6 | +#include <limits.h> |
| 7 | +#include <linux/falloc.h> |
| 8 | +#include <linux/fcntl.h> |
| 9 | +#include <linux/memfd.h> |
| 10 | +#include <sched.h> |
| 11 | +#include <stdio.h> |
| 12 | +#include <stdlib.h> |
| 13 | +#include <signal.h> |
| 14 | +#include <string.h> |
| 15 | +#include <sys/mman.h> |
| 16 | +#include <sys/stat.h> |
| 17 | +#include <sys/syscall.h> |
| 18 | +#include <unistd.h> |
| 19 | + |
| 20 | +#define MFD_DEF_SIZE 8192 |
| 21 | +#define STACK_SIZE 65535 |
| 22 | + |
| 23 | +static int sys_memfd_create(const char *name, |
| 24 | + unsigned int flags) |
| 25 | +{ |
| 26 | + return syscall(__NR_memfd_create, name, flags); |
| 27 | +} |
| 28 | + |
| 29 | +static int mfd_assert_new(const char *name, loff_t sz, unsigned int flags) |
| 30 | +{ |
| 31 | + int r, fd; |
| 32 | + |
| 33 | + fd = sys_memfd_create(name, flags); |
| 34 | + if (fd < 0) { |
| 35 | + printf("memfd_create(\"%s\", %u) failed: %m\n", |
| 36 | + name, flags); |
| 37 | + abort(); |
| 38 | + } |
| 39 | + |
| 40 | + r = ftruncate(fd, sz); |
| 41 | + if (r < 0) { |
| 42 | + printf("ftruncate(%llu) failed: %m\n", (unsigned long long)sz); |
| 43 | + abort(); |
| 44 | + } |
| 45 | + |
| 46 | + return fd; |
| 47 | +} |
| 48 | + |
| 49 | +static void mfd_fail_new(const char *name, unsigned int flags) |
| 50 | +{ |
| 51 | + int r; |
| 52 | + |
| 53 | + r = sys_memfd_create(name, flags); |
| 54 | + if (r >= 0) { |
| 55 | + printf("memfd_create(\"%s\", %u) succeeded, but failure expected\n", |
| 56 | + name, flags); |
| 57 | + close(r); |
| 58 | + abort(); |
| 59 | + } |
| 60 | +} |
| 61 | + |
| 62 | +static __u64 mfd_assert_get_seals(int fd) |
| 63 | +{ |
| 64 | + long r; |
| 65 | + |
| 66 | + r = fcntl(fd, F_GET_SEALS); |
| 67 | + if (r < 0) { |
| 68 | + printf("GET_SEALS(%d) failed: %m\n", fd); |
| 69 | + abort(); |
| 70 | + } |
| 71 | + |
| 72 | + return r; |
| 73 | +} |
| 74 | + |
| 75 | +static void mfd_assert_has_seals(int fd, __u64 seals) |
| 76 | +{ |
| 77 | + __u64 s; |
| 78 | + |
| 79 | + s = mfd_assert_get_seals(fd); |
| 80 | + if (s != seals) { |
| 81 | + printf("%llu != %llu = GET_SEALS(%d)\n", |
| 82 | + (unsigned long long)seals, (unsigned long long)s, fd); |
| 83 | + abort(); |
| 84 | + } |
| 85 | +} |
| 86 | + |
| 87 | +static void mfd_assert_add_seals(int fd, __u64 seals) |
| 88 | +{ |
| 89 | + long r; |
| 90 | + __u64 s; |
| 91 | + |
| 92 | + s = mfd_assert_get_seals(fd); |
| 93 | + r = fcntl(fd, F_ADD_SEALS, seals); |
| 94 | + if (r < 0) { |
| 95 | + printf("ADD_SEALS(%d, %llu -> %llu) failed: %m\n", |
| 96 | + fd, (unsigned long long)s, (unsigned long long)seals); |
| 97 | + abort(); |
| 98 | + } |
| 99 | +} |
| 100 | + |
| 101 | +static void mfd_fail_add_seals(int fd, __u64 seals) |
| 102 | +{ |
| 103 | + long r; |
| 104 | + __u64 s; |
| 105 | + |
| 106 | + r = fcntl(fd, F_GET_SEALS); |
| 107 | + if (r < 0) |
| 108 | + s = 0; |
| 109 | + else |
| 110 | + s = r; |
| 111 | + |
| 112 | + r = fcntl(fd, F_ADD_SEALS, seals); |
| 113 | + if (r >= 0) { |
| 114 | + printf("ADD_SEALS(%d, %llu -> %llu) didn't fail as expected\n", |
| 115 | + fd, (unsigned long long)s, (unsigned long long)seals); |
| 116 | + abort(); |
| 117 | + } |
| 118 | +} |
| 119 | + |
| 120 | +static void mfd_assert_size(int fd, size_t size) |
| 121 | +{ |
| 122 | + struct stat st; |
| 123 | + int r; |
| 124 | + |
| 125 | + r = fstat(fd, &st); |
| 126 | + if (r < 0) { |
| 127 | + printf("fstat(%d) failed: %m\n", fd); |
| 128 | + abort(); |
| 129 | + } else if (st.st_size != size) { |
| 130 | + printf("wrong file size %lld, but expected %lld\n", |
| 131 | + (long long)st.st_size, (long long)size); |
| 132 | + abort(); |
| 133 | + } |
| 134 | +} |
| 135 | + |
| 136 | +static int mfd_assert_dup(int fd) |
| 137 | +{ |
| 138 | + int r; |
| 139 | + |
| 140 | + r = dup(fd); |
| 141 | + if (r < 0) { |
| 142 | + printf("dup(%d) failed: %m\n", fd); |
| 143 | + abort(); |
| 144 | + } |
| 145 | + |
| 146 | + return r; |
| 147 | +} |
| 148 | + |
| 149 | +static void *mfd_assert_mmap_shared(int fd) |
| 150 | +{ |
| 151 | + void *p; |
| 152 | + |
| 153 | + p = mmap(NULL, |
| 154 | + MFD_DEF_SIZE, |
| 155 | + PROT_READ | PROT_WRITE, |
| 156 | + MAP_SHARED, |
| 157 | + fd, |
| 158 | + 0); |
| 159 | + if (p == MAP_FAILED) { |
| 160 | + printf("mmap() failed: %m\n"); |
| 161 | + abort(); |
| 162 | + } |
| 163 | + |
| 164 | + return p; |
| 165 | +} |
| 166 | + |
| 167 | +static void *mfd_assert_mmap_private(int fd) |
| 168 | +{ |
| 169 | + void *p; |
| 170 | + |
| 171 | + p = mmap(NULL, |
| 172 | + MFD_DEF_SIZE, |
| 173 | + PROT_READ, |
| 174 | + MAP_PRIVATE, |
| 175 | + fd, |
| 176 | + 0); |
| 177 | + if (p == MAP_FAILED) { |
| 178 | + printf("mmap() failed: %m\n"); |
| 179 | + abort(); |
| 180 | + } |
| 181 | + |
| 182 | + return p; |
| 183 | +} |
| 184 | + |
| 185 | +static int mfd_assert_open(int fd, int flags, mode_t mode) |
| 186 | +{ |
| 187 | + char buf[512]; |
| 188 | + int r; |
| 189 | + |
| 190 | + sprintf(buf, "/proc/self/fd/%d", fd); |
| 191 | + r = open(buf, flags, mode); |
| 192 | + if (r < 0) { |
| 193 | + printf("open(%s) failed: %m\n", buf); |
| 194 | + abort(); |
| 195 | + } |
| 196 | + |
| 197 | + return r; |
| 198 | +} |
| 199 | + |
| 200 | +static void mfd_fail_open(int fd, int flags, mode_t mode) |
| 201 | +{ |
| 202 | + char buf[512]; |
| 203 | + int r; |
| 204 | + |
| 205 | + sprintf(buf, "/proc/self/fd/%d", fd); |
| 206 | + r = open(buf, flags, mode); |
| 207 | + if (r >= 0) { |
| 208 | + printf("open(%s) didn't fail as expected\n"); |
| 209 | + abort(); |
| 210 | + } |
| 211 | +} |
| 212 | + |
| 213 | +static void mfd_assert_read(int fd) |
| 214 | +{ |
| 215 | + char buf[16]; |
| 216 | + void *p; |
| 217 | + ssize_t l; |
| 218 | + |
| 219 | + l = read(fd, buf, sizeof(buf)); |
| 220 | + if (l != sizeof(buf)) { |
| 221 | + printf("read() failed: %m\n"); |
| 222 | + abort(); |
| 223 | + } |
| 224 | + |
| 225 | + /* verify PROT_READ *is* allowed */ |
| 226 | + p = mmap(NULL, |
| 227 | + MFD_DEF_SIZE, |
| 228 | + PROT_READ, |
| 229 | + MAP_PRIVATE, |
| 230 | + fd, |
| 231 | + 0); |
| 232 | + if (p == MAP_FAILED) { |
| 233 | + printf("mmap() failed: %m\n"); |
| 234 | + abort(); |
| 235 | + } |
| 236 | + munmap(p, MFD_DEF_SIZE); |
| 237 | + |
| 238 | + /* verify MAP_PRIVATE is *always* allowed (even writable) */ |
| 239 | + p = mmap(NULL, |
| 240 | + MFD_DEF_SIZE, |
| 241 | + PROT_READ | PROT_WRITE, |
| 242 | + MAP_PRIVATE, |
| 243 | + fd, |
| 244 | + 0); |
| 245 | + if (p == MAP_FAILED) { |
| 246 | + printf("mmap() failed: %m\n"); |
| 247 | + abort(); |
| 248 | + } |
| 249 | + munmap(p, MFD_DEF_SIZE); |
| 250 | +} |
| 251 | + |
| 252 | +static void mfd_assert_write(int fd) |
| 253 | +{ |
| 254 | + ssize_t l; |
| 255 | + void *p; |
| 256 | + int r; |
| 257 | + |
| 258 | + /* verify write() succeeds */ |
| 259 | + l = write(fd, "\0\0\0\0", 4); |
| 260 | + if (l != 4) { |
| 261 | + printf("write() failed: %m\n"); |
| 262 | + abort(); |
| 263 | + } |
| 264 | + |
| 265 | + /* verify PROT_READ | PROT_WRITE is allowed */ |
| 266 | + p = mmap(NULL, |
| 267 | + MFD_DEF_SIZE, |
| 268 | + PROT_READ | PROT_WRITE, |
| 269 | + MAP_SHARED, |
| 270 | + fd, |
| 271 | + 0); |
| 272 | + if (p == MAP_FAILED) { |
| 273 | + printf("mmap() failed: %m\n"); |
| 274 | + abort(); |
| 275 | + } |
| 276 | + *(char *)p = 0; |
| 277 | + munmap(p, MFD_DEF_SIZE); |
| 278 | + |
| 279 | + /* verify PROT_WRITE is allowed */ |
| 280 | + p = mmap(NULL, |
| 281 | + MFD_DEF_SIZE, |
| 282 | + PROT_WRITE, |
| 283 | + MAP_SHARED, |
| 284 | + fd, |
| 285 | + 0); |
| 286 | + if (p == MAP_FAILED) { |
| 287 | + printf("mmap() failed: %m\n"); |
| 288 | + abort(); |
| 289 | + } |
| 290 | + *(char *)p = 0; |
| 291 | + munmap(p, MFD_DEF_SIZE); |
| 292 | + |
| 293 | + /* verify PROT_READ with MAP_SHARED is allowed and a following |
| 294 | + * mprotect(PROT_WRITE) allows writing */ |
| 295 | + p = mmap(NULL, |
| 296 | + MFD_DEF_SIZE, |
| 297 | + PROT_READ, |
| 298 | + MAP_SHARED, |
| 299 | + fd, |
| 300 | + 0); |
| 301 | + if (p == MAP_FAILED) { |
| 302 | + printf("mmap() failed: %m\n"); |
| 303 | + abort(); |
| 304 | + } |
| 305 | + |
| 306 | + r = mprotect(p, MFD_DEF_SIZE, PROT_READ | PROT_WRITE); |
| 307 | + if (r < 0) { |
| 308 | + printf("mprotect() failed: %m\n"); |
| 309 | + abort(); |
| 310 | + } |
| 311 | + |
| 312 | + *(char *)p = 0; |
| 313 | + munmap(p, MFD_DEF_SIZE); |
| 314 | + |
| 315 | + /* verify PUNCH_HOLE works */ |
| 316 | + r = fallocate(fd, |
| 317 | + FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, |
| 318 | + 0, |
| 319 | + MFD_DEF_SIZE); |
| 320 | + if (r < 0) { |
| 321 | + printf("fallocate(PUNCH_HOLE) failed: %m\n"); |
| 322 | + abort(); |
| 323 | + } |
| 324 | +} |
| 325 | + |
| 326 | +static void mfd_fail_write(int fd) |
| 327 | +{ |
| 328 | + ssize_t l; |
| 329 | + void *p; |
| 330 | + int r; |
| 331 | + |
| 332 | + /* verify write() fails */ |
| 333 | + l = write(fd, "data", 4); |
| 334 | + if (l != -EPERM) { |
| 335 | + printf("expected EPERM on write(), but got %d: %m\n", (int)l); |
| 336 | + abort(); |
| 337 | + } |
| 338 | + |
| 339 | + /* verify PROT_READ | PROT_WRITE is not allowed */ |
| 340 | + p = mmap(NULL, |
| 341 | + MFD_DEF_SIZE, |
| 342 | + PROT_READ | PROT_WRITE, |
| 343 | + MAP_SHARED, |
| 344 | + fd, |
| 345 | + 0); |
| 346 | + if (p != MAP_FAILED) { |
| 347 | + printf("mmap() didn't fail as expected\n"); |
| 348 | + abort(); |
| 349 | + } |
| 350 | + |
| 351 | + /* verify PROT_WRITE is not allowed */ |
| 352 | + p = mmap(NULL, |
| 353 | + MFD_DEF_SIZE, |
| 354 | + PROT_WRITE, |
| 355 | + MAP_SHARED, |
| 356 | + fd, |
| 357 | + 0); |
| 358 | + if (p != MAP_FAILED) { |
| 359 | + printf("mmap() didn't fail as expected\n"); |
| 360 | + abort(); |
| 361 | + } |
| 362 | + |
| 363 | + /* Verify PROT_READ with MAP_SHARED with a following mprotect is not |
| 364 | + * allowed. Note that for r/w the kernel already prevents the mmap. */ |
| 365 | + p = mmap(NULL, |
| 366 | + MFD_DEF_SIZE, |
| 367 | + PROT_READ, |
| 368 | + MAP_SHARED, |
| 369 | + fd, |
| 370 | + 0); |
| 371 | + if (p != MAP_FAILED) { |
| 372 | + r = mprotect(p, MFD_DEF_SIZE, PROT_READ | PROT_WRITE); |
| 373 | + if (r >= 0) { |
| 374 | + printf("mmap()+mprotect() didn't fail as expected\n"); |
| 375 | + abort(); |
| 376 | + } |
| 377 | + } |
| 378 | + |
| 379 | + /* verify PUNCH_HOLE fails */ |
| 380 | + r = fallocate(fd, |
| 381 | + FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, |
| 382 | + 0, |
| 383 | + MFD_DEF_SIZE); |
| 384 | + if (r >= 0) { |
| 385 | + printf("fallocate(PUNCH_HOLE) didn't fail as expected\n"); |
| 386 | + abort(); |
| 387 | + } |
| 388 | +} |
| 389 | + |
| 390 | +static void mfd_assert_shrink(int fd) |
| 391 | +{ |
| 392 | + int r, fd2; |
| 393 | + |
| 394 | + r = ftruncate(fd, MFD_DEF_SIZE / 2); |
| 395 | + if (r < 0) { |
| 396 | + printf("ftruncate(SHRINK) failed: %m\n"); |
| 397 | + abort(); |
| 398 | + } |
| 399 | + |
| 400 | + mfd_assert_size(fd, MFD_DEF_SIZE / 2); |
| 401 | + |
| 402 | + fd2 = mfd_assert_open(fd, |
| 403 | + O_RDWR | O_CREAT | O_TRUNC, |
| 404 | + S_IRUSR | S_IWUSR); |
| 405 | + close(fd2); |
| 406 | + |
| 407 | + mfd_assert_size(fd, 0); |
| 408 | +} |
| 409 | + |
| 410 | +static void mfd_fail_shrink(int fd) |
| 411 | +{ |
| 412 | + int r; |
| 413 | + |
| 414 | + r = ftruncate(fd, MFD_DEF_SIZE / 2); |
| 415 | + if (r >= 0) { |
| 416 | + printf("ftruncate(SHRINK) didn't fail as expected\n"); |
| 417 | + abort(); |
| 418 | + } |
| 419 | + |
| 420 | + mfd_fail_open(fd, |
| 421 | + O_RDWR | O_CREAT | O_TRUNC, |
| 422 | + S_IRUSR | S_IWUSR); |
| 423 | +} |
| 424 | + |
| 425 | +static void mfd_assert_grow(int fd) |
| 426 | +{ |
| 427 | + int r; |
| 428 | + |
| 429 | + r = ftruncate(fd, MFD_DEF_SIZE * 2); |
| 430 | + if (r < 0) { |
| 431 | + printf("ftruncate(GROW) failed: %m\n"); |
| 432 | + abort(); |
| 433 | + } |
| 434 | + |
| 435 | + mfd_assert_size(fd, MFD_DEF_SIZE * 2); |
| 436 | + |
| 437 | + r = fallocate(fd, |
| 438 | + 0, |
| 439 | + 0, |
| 440 | + MFD_DEF_SIZE * 4); |
| 441 | + if (r < 0) { |
| 442 | + printf("fallocate(ALLOC) failed: %m\n"); |
| 443 | + abort(); |
| 444 | + } |
| 445 | + |
| 446 | + mfd_assert_size(fd, MFD_DEF_SIZE * 4); |
| 447 | +} |
| 448 | + |
| 449 | +static void mfd_fail_grow(int fd) |
| 450 | +{ |
| 451 | + int r; |
| 452 | + |
| 453 | + r = ftruncate(fd, MFD_DEF_SIZE * 2); |
| 454 | + if (r >= 0) { |
| 455 | + printf("ftruncate(GROW) didn't fail as expected\n"); |
| 456 | + abort(); |
| 457 | + } |
| 458 | + |
| 459 | + r = fallocate(fd, |
| 460 | + 0, |
| 461 | + 0, |
| 462 | + MFD_DEF_SIZE * 4); |
| 463 | + if (r >= 0) { |
| 464 | + printf("fallocate(ALLOC) didn't fail as expected\n"); |
| 465 | + abort(); |
| 466 | + } |
| 467 | +} |
| 468 | + |
| 469 | +static void mfd_assert_grow_write(int fd) |
| 470 | +{ |
| 471 | + static char buf[MFD_DEF_SIZE * 8]; |
| 472 | + ssize_t l; |
| 473 | + |
| 474 | + l = pwrite(fd, buf, sizeof(buf), 0); |
| 475 | + if (l != sizeof(buf)) { |
| 476 | + printf("pwrite() failed: %m\n"); |
| 477 | + abort(); |
| 478 | + } |
| 479 | + |
| 480 | + mfd_assert_size(fd, MFD_DEF_SIZE * 8); |
| 481 | +} |
| 482 | + |
| 483 | +static void mfd_fail_grow_write(int fd) |
| 484 | +{ |
| 485 | + static char buf[MFD_DEF_SIZE * 8]; |
| 486 | + ssize_t l; |
| 487 | + |
| 488 | + l = pwrite(fd, buf, sizeof(buf), 0); |
| 489 | + if (l == sizeof(buf)) { |
| 490 | + printf("pwrite() didn't fail as expected\n"); |
| 491 | + abort(); |
| 492 | + } |
| 493 | +} |
| 494 | + |
| 495 | +static int idle_thread_fn(void *arg) |
| 496 | +{ |
| 497 | + sigset_t set; |
| 498 | + int sig; |
| 499 | + |
| 500 | + /* dummy waiter; SIGTERM terminates us anyway */ |
| 501 | + sigemptyset(&set); |
| 502 | + sigaddset(&set, SIGTERM); |
| 503 | + sigwait(&set, &sig); |
| 504 | + |
| 505 | + return 0; |
| 506 | +} |
| 507 | + |
| 508 | +static pid_t spawn_idle_thread(unsigned int flags) |
| 509 | +{ |
| 510 | + uint8_t *stack; |
| 511 | + pid_t pid; |
| 512 | + |
| 513 | + stack = malloc(STACK_SIZE); |
| 514 | + if (!stack) { |
| 515 | + printf("malloc(STACK_SIZE) failed: %m\n"); |
| 516 | + abort(); |
| 517 | + } |
| 518 | + |
| 519 | + pid = clone(idle_thread_fn, |
| 520 | + stack + STACK_SIZE, |
| 521 | + SIGCHLD | flags, |
| 522 | + NULL); |
| 523 | + if (pid < 0) { |
| 524 | + printf("clone() failed: %m\n"); |
| 525 | + abort(); |
| 526 | + } |
| 527 | + |
| 528 | + return pid; |
| 529 | +} |
| 530 | + |
| 531 | +static void join_idle_thread(pid_t pid) |
| 532 | +{ |
| 533 | + kill(pid, SIGTERM); |
| 534 | + waitpid(pid, NULL, 0); |
| 535 | +} |
| 536 | + |
| 537 | +/* |
| 538 | + * Test memfd_create() syscall |
| 539 | + * Verify syscall-argument validation, including name checks, flag validation |
| 540 | + * and more. |
| 541 | + */ |
| 542 | +static void test_create(void) |
| 543 | +{ |
| 544 | + char buf[2048]; |
| 545 | + int fd; |
| 546 | + |
| 547 | + /* test NULL name */ |
| 548 | + mfd_fail_new(NULL, 0); |
| 549 | + |
| 550 | + /* test over-long name (not zero-terminated) */ |
| 551 | + memset(buf, 0xff, sizeof(buf)); |
| 552 | + mfd_fail_new(buf, 0); |
| 553 | + |
| 554 | + /* test over-long zero-terminated name */ |
| 555 | + memset(buf, 0xff, sizeof(buf)); |
| 556 | + buf[sizeof(buf) - 1] = 0; |
| 557 | + mfd_fail_new(buf, 0); |
| 558 | + |
| 559 | + /* verify "" is a valid name */ |
| 560 | + fd = mfd_assert_new("", 0, 0); |
| 561 | + close(fd); |
| 562 | + |
| 563 | + /* verify invalid O_* open flags */ |
| 564 | + mfd_fail_new("", 0x0100); |
| 565 | + mfd_fail_new("", ~MFD_CLOEXEC); |
| 566 | + mfd_fail_new("", ~MFD_ALLOW_SEALING); |
| 567 | + mfd_fail_new("", ~0); |
| 568 | + mfd_fail_new("", 0x80000000U); |
| 569 | + |
| 570 | + /* verify MFD_CLOEXEC is allowed */ |
| 571 | + fd = mfd_assert_new("", 0, MFD_CLOEXEC); |
| 572 | + close(fd); |
| 573 | + |
| 574 | + /* verify MFD_ALLOW_SEALING is allowed */ |
| 575 | + fd = mfd_assert_new("", 0, MFD_ALLOW_SEALING); |
| 576 | + close(fd); |
| 577 | + |
| 578 | + /* verify MFD_ALLOW_SEALING | MFD_CLOEXEC is allowed */ |
| 579 | + fd = mfd_assert_new("", 0, MFD_ALLOW_SEALING | MFD_CLOEXEC); |
| 580 | + close(fd); |
| 581 | +} |
| 582 | + |
| 583 | +/* |
| 584 | + * Test basic sealing |
| 585 | + * A very basic sealing test to see whether setting/retrieving seals works. |
| 586 | + */ |
| 587 | +static void test_basic(void) |
| 588 | +{ |
| 589 | + int fd; |
| 590 | + |
| 591 | + fd = mfd_assert_new("kern_memfd_basic", |
| 592 | + MFD_DEF_SIZE, |
| 593 | + MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| 594 | + |
| 595 | + /* add basic seals */ |
| 596 | + mfd_assert_has_seals(fd, 0); |
| 597 | + mfd_assert_add_seals(fd, F_SEAL_SHRINK | |
| 598 | + F_SEAL_WRITE); |
| 599 | + mfd_assert_has_seals(fd, F_SEAL_SHRINK | |
| 600 | + F_SEAL_WRITE); |
| 601 | + |
| 602 | + /* add them again */ |
| 603 | + mfd_assert_add_seals(fd, F_SEAL_SHRINK | |
| 604 | + F_SEAL_WRITE); |
| 605 | + mfd_assert_has_seals(fd, F_SEAL_SHRINK | |
| 606 | + F_SEAL_WRITE); |
| 607 | + |
| 608 | + /* add more seals and seal against sealing */ |
| 609 | + mfd_assert_add_seals(fd, F_SEAL_GROW | F_SEAL_SEAL); |
| 610 | + mfd_assert_has_seals(fd, F_SEAL_SHRINK | |
| 611 | + F_SEAL_GROW | |
| 612 | + F_SEAL_WRITE | |
| 613 | + F_SEAL_SEAL); |
| 614 | + |
| 615 | + /* verify that sealing no longer works */ |
| 616 | + mfd_fail_add_seals(fd, F_SEAL_GROW); |
| 617 | + mfd_fail_add_seals(fd, 0); |
| 618 | + |
| 619 | + close(fd); |
| 620 | + |
| 621 | + /* verify sealing does not work without MFD_ALLOW_SEALING */ |
| 622 | + fd = mfd_assert_new("kern_memfd_basic", |
| 623 | + MFD_DEF_SIZE, |
| 624 | + MFD_CLOEXEC); |
| 625 | + mfd_assert_has_seals(fd, F_SEAL_SEAL); |
| 626 | + mfd_fail_add_seals(fd, F_SEAL_SHRINK | |
| 627 | + F_SEAL_GROW | |
| 628 | + F_SEAL_WRITE); |
| 629 | + mfd_assert_has_seals(fd, F_SEAL_SEAL); |
| 630 | + close(fd); |
| 631 | +} |
| 632 | + |
| 633 | +/* |
| 634 | + * Test SEAL_WRITE |
| 635 | + * Test whether SEAL_WRITE actually prevents modifications. |
| 636 | + */ |
| 637 | +static void test_seal_write(void) |
| 638 | +{ |
| 639 | + int fd; |
| 640 | + |
| 641 | + fd = mfd_assert_new("kern_memfd_seal_write", |
| 642 | + MFD_DEF_SIZE, |
| 643 | + MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| 644 | + mfd_assert_has_seals(fd, 0); |
| 645 | + mfd_assert_add_seals(fd, F_SEAL_WRITE); |
| 646 | + mfd_assert_has_seals(fd, F_SEAL_WRITE); |
| 647 | + |
| 648 | + mfd_assert_read(fd); |
| 649 | + mfd_fail_write(fd); |
| 650 | + mfd_assert_shrink(fd); |
| 651 | + mfd_assert_grow(fd); |
| 652 | + mfd_fail_grow_write(fd); |
| 653 | + |
| 654 | + close(fd); |
| 655 | +} |
| 656 | + |
| 657 | +/* |
| 658 | + * Test SEAL_SHRINK |
| 659 | + * Test whether SEAL_SHRINK actually prevents shrinking |
| 660 | + */ |
| 661 | +static void test_seal_shrink(void) |
| 662 | +{ |
| 663 | + int fd; |
| 664 | + |
| 665 | + fd = mfd_assert_new("kern_memfd_seal_shrink", |
| 666 | + MFD_DEF_SIZE, |
| 667 | + MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| 668 | + mfd_assert_has_seals(fd, 0); |
| 669 | + mfd_assert_add_seals(fd, F_SEAL_SHRINK); |
| 670 | + mfd_assert_has_seals(fd, F_SEAL_SHRINK); |
| 671 | + |
| 672 | + mfd_assert_read(fd); |
| 673 | + mfd_assert_write(fd); |
| 674 | + mfd_fail_shrink(fd); |
| 675 | + mfd_assert_grow(fd); |
| 676 | + mfd_assert_grow_write(fd); |
| 677 | + |
| 678 | + close(fd); |
| 679 | +} |
| 680 | + |
| 681 | +/* |
| 682 | + * Test SEAL_GROW |
| 683 | + * Test whether SEAL_GROW actually prevents growing |
| 684 | + */ |
| 685 | +static void test_seal_grow(void) |
| 686 | +{ |
| 687 | + int fd; |
| 688 | + |
| 689 | + fd = mfd_assert_new("kern_memfd_seal_grow", |
| 690 | + MFD_DEF_SIZE, |
| 691 | + MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| 692 | + mfd_assert_has_seals(fd, 0); |
| 693 | + mfd_assert_add_seals(fd, F_SEAL_GROW); |
| 694 | + mfd_assert_has_seals(fd, F_SEAL_GROW); |
| 695 | + |
| 696 | + mfd_assert_read(fd); |
| 697 | + mfd_assert_write(fd); |
| 698 | + mfd_assert_shrink(fd); |
| 699 | + mfd_fail_grow(fd); |
| 700 | + mfd_fail_grow_write(fd); |
| 701 | + |
| 702 | + close(fd); |
| 703 | +} |
| 704 | + |
| 705 | +/* |
| 706 | + * Test SEAL_SHRINK | SEAL_GROW |
| 707 | + * Test whether SEAL_SHRINK | SEAL_GROW actually prevents resizing |
| 708 | + */ |
| 709 | +static void test_seal_resize(void) |
| 710 | +{ |
| 711 | + int fd; |
| 712 | + |
| 713 | + fd = mfd_assert_new("kern_memfd_seal_resize", |
| 714 | + MFD_DEF_SIZE, |
| 715 | + MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| 716 | + mfd_assert_has_seals(fd, 0); |
| 717 | + mfd_assert_add_seals(fd, F_SEAL_SHRINK | F_SEAL_GROW); |
| 718 | + mfd_assert_has_seals(fd, F_SEAL_SHRINK | F_SEAL_GROW); |
| 719 | + |
| 720 | + mfd_assert_read(fd); |
| 721 | + mfd_assert_write(fd); |
| 722 | + mfd_fail_shrink(fd); |
| 723 | + mfd_fail_grow(fd); |
| 724 | + mfd_fail_grow_write(fd); |
| 725 | + |
| 726 | + close(fd); |
| 727 | +} |
| 728 | + |
| 729 | +/* |
| 730 | + * Test sharing via dup() |
| 731 | + * Test that seals are shared between dupped FDs and they're all equal. |
| 732 | + */ |
| 733 | +static void test_share_dup(void) |
| 734 | +{ |
| 735 | + int fd, fd2; |
| 736 | + |
| 737 | + fd = mfd_assert_new("kern_memfd_share_dup", |
| 738 | + MFD_DEF_SIZE, |
| 739 | + MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| 740 | + mfd_assert_has_seals(fd, 0); |
| 741 | + |
| 742 | + fd2 = mfd_assert_dup(fd); |
| 743 | + mfd_assert_has_seals(fd2, 0); |
| 744 | + |
| 745 | + mfd_assert_add_seals(fd, F_SEAL_WRITE); |
| 746 | + mfd_assert_has_seals(fd, F_SEAL_WRITE); |
| 747 | + mfd_assert_has_seals(fd2, F_SEAL_WRITE); |
| 748 | + |
| 749 | + mfd_assert_add_seals(fd2, F_SEAL_SHRINK); |
| 750 | + mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK); |
| 751 | + mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK); |
| 752 | + |
| 753 | + mfd_assert_add_seals(fd, F_SEAL_SEAL); |
| 754 | + mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL); |
| 755 | + mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL); |
| 756 | + |
| 757 | + mfd_fail_add_seals(fd, F_SEAL_GROW); |
| 758 | + mfd_fail_add_seals(fd2, F_SEAL_GROW); |
| 759 | + mfd_fail_add_seals(fd, F_SEAL_SEAL); |
| 760 | + mfd_fail_add_seals(fd2, F_SEAL_SEAL); |
| 761 | + |
| 762 | + close(fd2); |
| 763 | + |
| 764 | + mfd_fail_add_seals(fd, F_SEAL_GROW); |
| 765 | + close(fd); |
| 766 | +} |
| 767 | + |
| 768 | +/* |
| 769 | + * Test sealing with active mmap()s |
| 770 | + * Modifying seals is only allowed if no other mmap() refs exist. |
| 771 | + */ |
| 772 | +static void test_share_mmap(void) |
| 773 | +{ |
| 774 | + int fd; |
| 775 | + void *p; |
| 776 | + |
| 777 | + fd = mfd_assert_new("kern_memfd_share_mmap", |
| 778 | + MFD_DEF_SIZE, |
| 779 | + MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| 780 | + mfd_assert_has_seals(fd, 0); |
| 781 | + |
| 782 | + /* shared/writable ref prevents sealing WRITE, but allows others */ |
| 783 | + p = mfd_assert_mmap_shared(fd); |
| 784 | + mfd_fail_add_seals(fd, F_SEAL_WRITE); |
| 785 | + mfd_assert_has_seals(fd, 0); |
| 786 | + mfd_assert_add_seals(fd, F_SEAL_SHRINK); |
| 787 | + mfd_assert_has_seals(fd, F_SEAL_SHRINK); |
| 788 | + munmap(p, MFD_DEF_SIZE); |
| 789 | + |
| 790 | + /* readable ref allows sealing */ |
| 791 | + p = mfd_assert_mmap_private(fd); |
| 792 | + mfd_assert_add_seals(fd, F_SEAL_WRITE); |
| 793 | + mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK); |
| 794 | + munmap(p, MFD_DEF_SIZE); |
| 795 | + |
| 796 | + close(fd); |
| 797 | +} |
| 798 | + |
| 799 | +/* |
| 800 | + * Test sealing with open(/proc/self/fd/%d) |
| 801 | + * Via /proc we can get access to a separate file-context for the same memfd. |
| 802 | + * This is *not* like dup(), but like a real separate open(). Make sure the |
| 803 | + * semantics are as expected and we correctly check for RDONLY / WRONLY / RDWR. |
| 804 | + */ |
| 805 | +static void test_share_open(void) |
| 806 | +{ |
| 807 | + int fd, fd2; |
| 808 | + |
| 809 | + fd = mfd_assert_new("kern_memfd_share_open", |
| 810 | + MFD_DEF_SIZE, |
| 811 | + MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| 812 | + mfd_assert_has_seals(fd, 0); |
| 813 | + |
| 814 | + fd2 = mfd_assert_open(fd, O_RDWR, 0); |
| 815 | + mfd_assert_add_seals(fd, F_SEAL_WRITE); |
| 816 | + mfd_assert_has_seals(fd, F_SEAL_WRITE); |
| 817 | + mfd_assert_has_seals(fd2, F_SEAL_WRITE); |
| 818 | + |
| 819 | + mfd_assert_add_seals(fd2, F_SEAL_SHRINK); |
| 820 | + mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK); |
| 821 | + mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK); |
| 822 | + |
| 823 | + close(fd); |
| 824 | + fd = mfd_assert_open(fd2, O_RDONLY, 0); |
| 825 | + |
| 826 | + mfd_fail_add_seals(fd, F_SEAL_SEAL); |
| 827 | + mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK); |
| 828 | + mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK); |
| 829 | + |
| 830 | + close(fd2); |
| 831 | + fd2 = mfd_assert_open(fd, O_RDWR, 0); |
| 832 | + |
| 833 | + mfd_assert_add_seals(fd2, F_SEAL_SEAL); |
| 834 | + mfd_assert_has_seals(fd, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL); |
| 835 | + mfd_assert_has_seals(fd2, F_SEAL_WRITE | F_SEAL_SHRINK | F_SEAL_SEAL); |
| 836 | + |
| 837 | + close(fd2); |
| 838 | + close(fd); |
| 839 | +} |
| 840 | + |
| 841 | +/* |
| 842 | + * Test sharing via fork() |
| 843 | + * Test whether seal-modifications work as expected with forked childs. |
| 844 | + */ |
| 845 | +static void test_share_fork(void) |
| 846 | +{ |
| 847 | + int fd; |
| 848 | + pid_t pid; |
| 849 | + |
| 850 | + fd = mfd_assert_new("kern_memfd_share_fork", |
| 851 | + MFD_DEF_SIZE, |
| 852 | + MFD_CLOEXEC | MFD_ALLOW_SEALING); |
| 853 | + mfd_assert_has_seals(fd, 0); |
| 854 | + |
| 855 | + pid = spawn_idle_thread(0); |
| 856 | + mfd_assert_add_seals(fd, F_SEAL_SEAL); |
| 857 | + mfd_assert_has_seals(fd, F_SEAL_SEAL); |
| 858 | + |
| 859 | + mfd_fail_add_seals(fd, F_SEAL_WRITE); |
| 860 | + mfd_assert_has_seals(fd, F_SEAL_SEAL); |
| 861 | + |
| 862 | + join_idle_thread(pid); |
| 863 | + |
| 864 | + mfd_fail_add_seals(fd, F_SEAL_WRITE); |
| 865 | + mfd_assert_has_seals(fd, F_SEAL_SEAL); |
| 866 | + |
| 867 | + close(fd); |
| 868 | +} |
| 869 | + |
| 870 | +int main(int argc, char **argv) |
| 871 | +{ |
| 872 | + pid_t pid; |
| 873 | + |
| 874 | + printf("memfd: CREATE\n"); |
| 875 | + test_create(); |
| 876 | + printf("memfd: BASIC\n"); |
| 877 | + test_basic(); |
| 878 | + |
| 879 | + printf("memfd: SEAL-WRITE\n"); |
| 880 | + test_seal_write(); |
| 881 | + printf("memfd: SEAL-SHRINK\n"); |
| 882 | + test_seal_shrink(); |
| 883 | + printf("memfd: SEAL-GROW\n"); |
| 884 | + test_seal_grow(); |
| 885 | + printf("memfd: SEAL-RESIZE\n"); |
| 886 | + test_seal_resize(); |
| 887 | + |
| 888 | + printf("memfd: SHARE-DUP\n"); |
| 889 | + test_share_dup(); |
| 890 | + printf("memfd: SHARE-MMAP\n"); |
| 891 | + test_share_mmap(); |
| 892 | + printf("memfd: SHARE-OPEN\n"); |
| 893 | + test_share_open(); |
| 894 | + printf("memfd: SHARE-FORK\n"); |
| 895 | + test_share_fork(); |
| 896 | + |
| 897 | + /* Run test-suite in a multi-threaded environment with a shared |
| 898 | + * file-table. */ |
| 899 | + pid = spawn_idle_thread(CLONE_FILES | CLONE_FS | CLONE_VM); |
| 900 | + printf("memfd: SHARE-DUP (shared file-table)\n"); |
| 901 | + test_share_dup(); |
| 902 | + printf("memfd: SHARE-MMAP (shared file-table)\n"); |
| 903 | + test_share_mmap(); |
| 904 | + printf("memfd: SHARE-OPEN (shared file-table)\n"); |
| 905 | + test_share_open(); |
| 906 | + printf("memfd: SHARE-FORK (shared file-table)\n"); |
| 907 | + test_share_fork(); |
| 908 | + join_idle_thread(pid); |
| 909 | + |
| 910 | + printf("memfd: DONE\n"); |
| 911 | + |
| 912 | + return 0; |
| 913 | +} |