// https://syzkaller.appspot.com/bug?id=3c1f47967b7cbd399d3ba3e65f297a29aa1c5f92 // 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 #include __attribute__((noreturn)) static void doexit(int status) { volatile unsigned i; syscall(__NR_exit_group, status); for (i = 0;; i++) { } } #include #include #include #include #include #include #include const int kFailStatus = 67; const int kRetryStatus = 69; static void fail(const char* msg, ...) { int e = errno; va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); doexit((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus); } static void exitf(const char* msg, ...) { int e = errno; va_list args; va_start(args, msg); vfprintf(stderr, msg, args); va_end(args); fprintf(stderr, " (errno %d)\n", e); doexit(kRetryStatus); } static uint64_t current_time_ms() { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) fail("clock_gettime failed"); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } static void use_temporary_dir() { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) fail("failed to mkdtemp"); if (chmod(tmpdir, 0777)) fail("failed to chmod"); if (chdir(tmpdir)) fail("failed to chdir"); } static uintptr_t syz_open_dev(uintptr_t a0, uintptr_t a1, uintptr_t a2) { if (a0 == 0xc || a0 == 0xb) { char buf[128]; sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1, (uint8_t)a2); return open(buf, O_RDWR, 0); } else { char buf[1024]; char* hash; strncpy(buf, (char*)a0, sizeof(buf)); buf[sizeof(buf) - 1] = 0; while ((hash = strchr(buf, '#'))) { *hash = '0' + (char)(a1 % 10); a1 /= 10; } return open(buf, a2, 0); } } static void remove_dir(const char* dir) { DIR* dp; struct dirent* ep; int iter = 0; retry: dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exitf("opendir(%s) failed due to NOFILE, exiting", dir); } exitf("opendir(%s) failed", dir); } while ((ep = readdir(dp))) { if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0) continue; char filename[FILENAME_MAX]; snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name); struct stat st; if (lstat(filename, &st)) exitf("lstat(%s) failed", filename); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } int i; for (i = 0;; i++) { if (unlink(filename) == 0) break; if (errno == EROFS) { break; } if (errno != EBUSY || i > 100) exitf("unlink(%s) failed", filename); if (umount2(filename, MNT_DETACH)) exitf("umount(%s) failed", filename); } } closedir(dp); int i; for (i = 0;; i++) { if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EROFS) { break; } if (errno == EBUSY) { if (umount2(dir, MNT_DETACH)) exitf("umount(%s) failed", dir); continue; } if (errno == ENOTEMPTY) { if (iter < 100) { iter++; goto retry; } } } exitf("rmdir(%s) failed", dir); } } static void test(); void loop() { int iter; for (iter = 0;; iter++) { char cwdbuf[256]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) fail("failed to mkdir"); int pid = fork(); if (pid < 0) fail("loop fork failed"); if (pid == 0) { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); if (chdir(cwdbuf)) fail("failed to chdir"); test(); doexit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { int res = waitpid(-1, &status, __WALL | WNOHANG); if (res == pid) break; usleep(1000); if (current_time_ms() - start > 5 * 1000) { kill(-pid, SIGKILL); kill(pid, SIGKILL); while (waitpid(-1, &status, __WALL) != pid) { } break; } } remove_dir(cwdbuf); } } long r[1]; void test() { memset(r, -1, sizeof(r)); syscall(__NR_mmap, 0x20000000, 0xfff000, 3, 0x32, -1, 0); memcpy((void*)0x20000000, "/dev/sg#", 9); r[0] = syz_open_dev(0x20000000, 0, 2); *(uint64_t*)0x20001000 = 0; *(uint64_t*)0x20001008 = 6; *(uint16_t*)0x20001010 = 0; *(uint16_t*)0x20001012 = 0; *(uint32_t*)0x20001014 = 0; *(uint64_t*)0x20001018 = 0; *(uint64_t*)0x20001020 = 0; *(uint16_t*)0x20001028 = 0; *(uint16_t*)0x2000102a = 0; *(uint32_t*)0x2000102c = 7; *(uint64_t*)0x20001030 = 0; *(uint64_t*)0x20001038 = 0x2710; *(uint16_t*)0x20001040 = 0; *(uint16_t*)0x20001042 = 0; *(uint32_t*)0x20001044 = 0; *(uint64_t*)0x20001048 = 0; *(uint64_t*)0x20001050 = 0; *(uint16_t*)0x20001058 = 0; *(uint16_t*)0x2000105a = 0; *(uint32_t*)0x2000105c = 0; syscall(__NR_write, r[0], 0x20001000, 0x60); *(uint64_t*)0x20347000 = 0x20272fa3; *(uint64_t*)0x20347008 = 0x76; *(uint64_t*)0x20347010 = 0x202d9000; *(uint64_t*)0x20347018 = 0x69; *(uint64_t*)0x20347020 = 0x20e68000; *(uint64_t*)0x20347028 = 0; *(uint64_t*)0x20347030 = 0x20726000; *(uint64_t*)0x20347038 = 0; *(uint64_t*)0x20347040 = 0x20ba7fc3; *(uint64_t*)0x20347048 = 0x3d; *(uint64_t*)0x20347050 = 0x20e86f14; *(uint64_t*)0x20347058 = 0xec; syscall(__NR_readv, r[0], 0x20347000, 6); } int main() { char* cwd = get_current_dir_name(); for (;;) { if (chdir(cwd)) fail("failed to chdir"); use_temporary_dir(); loop(); } }