// https://syzkaller.appspot.com/bug?id=68b3528dc42805d2128b6c5620d74fe87c3bfbdf // 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 #include #ifndef __NR_memfd_create #define __NR_memfd_create 319 #endif static unsigned long long procid; struct fs_image_segment { void* data; uintptr_t size; uintptr_t offset; }; static int setup_loop_device(long unsigned size, long unsigned nsegs, struct fs_image_segment* segs, const char* loopname, int* memfd_p, int* loopfd_p) { int err = 0, loopfd = -1; int memfd = syscall(__NR_memfd_create, "syzkaller", 0); if (memfd == -1) { err = errno; goto error; } if (ftruncate(memfd, size)) { err = errno; goto error_close_memfd; } for (size_t i = 0; i < nsegs; i++) { if (pwrite(memfd, segs[i].data, segs[i].size, segs[i].offset) < 0) { } } 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; } } *memfd_p = memfd; *loopfd_p = loopfd; return 0; error_close_loop: close(loopfd); error_close_memfd: close(memfd); error: errno = err; return -1; } static long syz_mount_image(volatile long fsarg, volatile long dir, volatile unsigned long size, volatile unsigned long nsegs, volatile long segments, volatile long flags, volatile long optsarg, volatile long change_dir) { struct fs_image_segment* segs = (struct fs_image_segment*)segments; int res = -1, err = 0, loopfd = -1, memfd = -1, need_loop_device = !!segs; char* mount_opts = (char*)optsarg; char* target = (char*)dir; char* fs = (char*)fsarg; char* source = NULL; char loopname[64]; if (need_loop_device) { memset(loopname, 0, sizeof(loopname)); snprintf(loopname, sizeof(loopname), "/dev/loop%llu", procid); if (setup_loop_device(size, nsegs, segs, loopname, &memfd, &loopfd) == -1) return -1; source = loopname; } mkdir(target, 0777); char opts[256]; memset(opts, 0, sizeof(opts)); if (strlen(mount_opts) > (sizeof(opts) - 32)) { } strncpy(opts, mount_opts, 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"); } res = mount(source, target, fs, flags, opts); if (res == -1) { err = errno; goto error_clear_loop; } res = open(target, O_RDONLY | O_DIRECTORY); if (res == -1) { err = errno; goto error_clear_loop; } if (change_dir) { res = chdir(target); if (res == -1) { err = errno; } } error_clear_loop: if (need_loop_device) { ioctl(loopfd, LOOP_CLR_FD, 0); close(loopfd); close(memfd); } errno = err; return res; } int main(void) { syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); memcpy((void*)0x20000000, "gfs2\000", 5); memcpy((void*)0x20000100, "./file0\000", 8); *(uint64_t*)0x20000200 = 0x200002c0; memcpy( (void*)0x200002c0, "\x01\x16\x19\x70\x00\x00\x00\x01\x00\x03\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x64\x00\x00\x00\x00\x00\x00\x07\x09\x00\x00\x07\x6c\x00\x00\x00\x00" "\x00\x00\x10\x00\x00\x00\x00\x0c\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" "\x00\x02\x22\x00\x00\x00\x00\x00\x08\x19\x00\x00\x00\x01\x00\x00\x00\x00" "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x00" "\x00\x00\x00\x00\x09\x25\x6c\x6f\x63\x6b\x5f\xdd\x8c\x1d\x1f\xb7\xdb\xd8" "\xbe\x74\x0c\xd2\x77\x87\xd4\x2d\xd8\x39\x11\x06\xad\x90\x25\xb2\x55\x8a" "\x21\xef\x01\xdb\x14\x7f\x48\x88\x53\x35\x8c\xf5\xe6\xdf\xc7\x34\xff\x0c" "\x65\x80\x8c\xe7\xf3\x07\x7c\x74\x63\x5f\xd3\xd7\xc3\x74\x75\xe8\x11\xa1" "\xba\x85\xe7\x1e\x95\x8a\xd1\xf3\x50\x63\xb4\x89\xd9\xb3\xcc\xb9\x9f\x60" "\x74\x64\xc1\x6c\x7d\x6e\xf0\x5c\x4a\x2f\xc8\xde\x93\xbc\xbe\xf0\x1d\x0b" "\xf9\x94\xb3\x11\x2c\x69\x4c\x17\xe5\xc1\x4b\x70\xaa\xe7\x6c\xd6\xb9\x8f" "\x54\x67\xc6\xe2\x61\xd4\x0c\x8e\x13\xb2\xb1\x66\xc0\x1d\xdd\x08\x2f\x92" "\x6d\x5a\x7c\x22\xf6\x49\xc1\xc8\x05\x2a\x94\xc8\xe7\xca\xf5\xb4\x8a\x07" "\x8c\x43\x7d\xac\xde\x26\xa2\x27\x86\x1e\x10\x75\x1c\x37\xde\xce\x96\xba" "\x80\xd5\x68\x91\x56\x97\xcc\x82\x02\xf7\xd1\xc3\x7e\x31\x3d\x76\xae\xc5" "\x4e\xd2\x58\x74\x8d\xb0\x7a\xdc\x83\x96\x57\x2c\xee\x71\x55\x1a\xb4\x59" "\x57\x9c\x5a\x60\x3b\xfc\x97\x56\x5b\xa1\x5e\x84\x8b\x63\x7c\xd0\xde\x94" "\x95\xce\x4a\x86\x40\x10\xdf\x46", 332); *(uint64_t*)0x20000208 = 0x14c; *(uint64_t*)0x20000210 = 0x10000; *(uint8_t*)0x20000440 = 0; syz_mount_image(0x20000000, 0x20000100, 0x8100000, 1, 0x20000200, 8, 0x20000440, 0); return 0; }