// https://syzkaller.appspot.com/bug?id=e925f35f91b20fb565507134085b4d65824e5eb0 // autogenerated by syzkaller (http://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include extern unsigned long long procid; struct fs_image_segment { void* data; uintptr_t size; uintptr_t offset; }; #define IMAGE_MAX_SEGMENTS 4096 #define IMAGE_MAX_SIZE (129 << 20) #define SYZ_memfd_create 356 static uintptr_t syz_mount_image(uintptr_t fs, uintptr_t dir, uintptr_t size, uintptr_t nsegs, uintptr_t segments, uintptr_t flags, uintptr_t opts) { char loopname[64]; int loopfd, err = 0, res = -1; uintptr_t i; struct fs_image_segment* segs = (struct fs_image_segment*)segments; if (nsegs > IMAGE_MAX_SEGMENTS) nsegs = IMAGE_MAX_SEGMENTS; for (i = 0; i < nsegs; i++) { if (segs[i].size > IMAGE_MAX_SIZE) segs[i].size = IMAGE_MAX_SIZE; segs[i].offset %= IMAGE_MAX_SIZE; if (segs[i].offset > IMAGE_MAX_SIZE - segs[i].size) segs[i].offset = IMAGE_MAX_SIZE - segs[i].size; if (size < segs[i].offset + segs[i].offset) size = segs[i].offset + segs[i].offset; } if (size > IMAGE_MAX_SIZE) size = IMAGE_MAX_SIZE; int memfd = syscall(SYZ_memfd_create, "syz_mount_image", 0); if (memfd == -1) { err = errno; goto error; } if (ftruncate(memfd, size)) { err = errno; goto error_close_memfd; } for (i = 0; i < nsegs; i++) { if (pwrite(memfd, segs[i].data, segs[i].size, segs[i].offset) < 0) { } } snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid); loopfd = open(loopname, O_RDWR); if (loopfd == -1) { err = errno; goto error_close_memfd; } if (ioctl(loopfd, LOOP_SET_FD, memfd)) { if (errno != EBUSY) { err = errno; goto error_close_loop; } ioctl(loopfd, LOOP_CLR_FD, 0); usleep(1000); if (ioctl(loopfd, LOOP_SET_FD, memfd)) { err = errno; goto error_close_loop; } } mkdir((char*)dir, 0777); if (strcmp((char*)fs, "iso9660") == 0) flags |= MS_RDONLY; if (mount(loopname, (char*)dir, (char*)fs, flags, (char*)opts)) { err = errno; goto error_clear_loop; } res = 0; error_clear_loop: ioctl(loopfd, LOOP_CLR_FD, 0); error_close_loop: close(loopfd); error_close_memfd: close(memfd); error: errno = err; return res; } static void execute_one(); extern unsigned long long procid; void loop() { while (1) { execute_one(); } } struct thread_t { int created, running, call; pthread_t th; }; static struct thread_t threads[16]; static void execute_call(int call); static int running; static int collide; static void* thr(void* arg) { struct thread_t* th = (struct thread_t*)arg; for (;;) { while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) syscall(SYS_futex, &th->running, FUTEX_WAIT, 0, 0); execute_call(th->call); __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); __atomic_store_n(&th->running, 0, __ATOMIC_RELEASE); syscall(SYS_futex, &th->running, FUTEX_WAKE); } return 0; } static void execute(int num_calls) { int call, thread; running = 0; for (call = 0; call < num_calls; call++) { for (thread = 0; thread < sizeof(threads) / sizeof(threads[0]); thread++) { struct thread_t* th = &threads[thread]; if (!th->created) { th->created = 1; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setstacksize(&attr, 128 << 10); pthread_create(&th->th, &attr, thr, th); } if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) { th->call = call; __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); __atomic_store_n(&th->running, 1, __ATOMIC_RELEASE); syscall(SYS_futex, &th->running, FUTEX_WAKE); if (collide && call % 2) break; struct timespec ts; ts.tv_sec = 0; ts.tv_nsec = 20 * 1000 * 1000; syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts); if (running) usleep((call == num_calls - 1) ? 10000 : 1000); break; } } } } #ifndef __NR_chown #define __NR_chown 182 #endif #ifndef __NR_lsetxattr #define __NR_lsetxattr 227 #endif #ifndef __NR_write #define __NR_write 4 #endif #ifndef __NR_mmap #define __NR_mmap 192 #endif #ifndef __NR_creat #define __NR_creat 8 #endif #undef __NR_mmap #define __NR_mmap __NR_mmap2 uint64_t r[1] = {0xffffffffffffffff}; unsigned long long procid; void execute_call(int call) { long res; switch (call) { case 0: memcpy((void*)0x20000080, "./file0", 8); res = syscall(__NR_creat, 0x20000080, 0); if (res != -1) r[0] = res; break; case 1: memcpy((void*)0x20000780, "jfs", 4); memcpy((void*)0x20000300, "./file0", 8); *(uint32_t*)0x20000700 = 0x20000200; *(uint32_t*)0x20000704 = 0; *(uint32_t*)0x20000708 = 0x7fff; *(uint32_t*)0x2000070c = 0x20000340; *(uint32_t*)0x20000710 = 0; *(uint32_t*)0x20000714 = 1; *(uint32_t*)0x20000718 = 0x20000440; *(uint32_t*)0x2000071c = 0; *(uint32_t*)0x20000720 = 0; *(uint32_t*)0x20000724 = 0x200004c0; *(uint32_t*)0x20000728 = 0; *(uint32_t*)0x2000072c = 0x3ff; *(uint32_t*)0x20000730 = 0x20000580; *(uint32_t*)0x20000734 = 0; *(uint32_t*)0x20000738 = 7; *(uint32_t*)0x2000073c = 0x20000280; *(uint32_t*)0x20000740 = 0; *(uint32_t*)0x20000744 = 2; *(uint32_t*)0x20000748 = 0x20000640; *(uint32_t*)0x2000074c = 0; *(uint32_t*)0x20000750 = 0xfffffff9; *(uint32_t*)0x20000754 = 0x20000680; *(uint32_t*)0x20000758 = 0; *(uint32_t*)0x2000075c = 0xca; syz_mount_image(0x20000780, 0x20000300, 0x80000, 8, 0x20000700, 0x1000, 0x20000ac0); break; case 2: memcpy((void*)0x20000d00, "./file0", 8); syscall(__NR_chown, 0x20000d00, 0, 0); break; case 3: memcpy((void*)0x20712ff8, "./file0", 8); memcpy((void*)0x20faffe7, "security.capability", 20); memcpy((void*)0x20000100, "\x00\x00\x00\x02\x01\x00\x00\x00\x00\x00\x00\x01" "\x04\x00\x00\x00\x00\x00\x00\x00", 20); syscall(__NR_lsetxattr, 0x20712ff8, 0x20faffe7, 0x20000100, 0x14, 0); break; case 4: *(uint8_t*)0x20000b80 = 0x38; *(uint8_t*)0x20000b81 = 0x37; *(uint8_t*)0x20000b82 = 0x39; syscall(__NR_write, r[0], 0x20000b80, 3); break; } } void execute_one() { execute(5); collide = 1; execute(5); } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); for (;;) { loop(); } }