// https://syzkaller.appspot.com/bug?id=f575bceae809f8c7e64b9996bee279950ada272d // autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #include #include 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 319 static long syz_mount_image(long fsarg, long dir, unsigned long size, unsigned long nsegs, long segments, long flags, long optsarg) { char loopname[64], fs[32], opts[256]; int loopfd, err = 0, res = -1; unsigned long 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); memset(fs, 0, sizeof(fs)); strncpy(fs, (char*)fsarg, sizeof(fs) - 1); memset(opts, 0, sizeof(opts)); strncpy(opts, (char*)optsarg, sizeof(opts) - 32); if (strcmp(fs, "iso9660") == 0) { flags |= MS_RDONLY; } else if (strncmp(fs, "ext", 3) == 0) { if (strstr(opts, "errors=panic") || strstr(opts, "errors=remount-ro") == 0) strcat(opts, ",errors=continue"); } else if (strcmp(fs, "xfs") == 0) { strcat(opts, ",nouuid"); } if (mount(loopname, (char*)dir, fs, flags, 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; } int main() { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); memcpy((void*)0x20000000, "vfat", 5); memcpy((void*)0x200004c0, "./file0", 8); syz_mount_image(0x20000000, 0x200004c0, 0, 0, 0x20000300, 0, 0x20000240); memcpy((void*)0x20000080, "127.0.0.1", 10); memcpy((void*)0x20000100, "./file1", 8); memcpy((void*)0x20000140, "9p", 3); memcpy((void*)0x200001c0, "trans=tcp,", 10); memcpy((void*)0x200001ca, "port", 4); *(uint8_t*)0x200001ce = 0x3d; sprintf((char*)0x200001cf, "0x%016llx", (long long)0); *(uint8_t*)0x200001e1 = 0x2c; *(uint8_t*)0x200001e2 = 0; syscall(__NR_mount, 0x20000080, 0x20000100, 0x20000140, 0, 0x200001c0); memcpy((void*)0x200000c0, "./file0", 8); memcpy((void*)0x20000040, "9p", 3); syscall(__NR_mount, 0, 0x200000c0, 0x20000040, 0, 0x200001c0); return 0; }