// https://syzkaller.appspot.com/bug?id=ef0179626fa1d02db03cd04dde6b57dae3d337a9 // 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 #include #include #include #include #include #include #include #include #include unsigned long long procid; static void sleep_ms(uint64_t ms) { usleep(ms * 1000); } static uint64_t current_time_ms(void) { struct timespec ts; if (clock_gettime(CLOCK_MONOTONIC, &ts)) exit(1); return (uint64_t)ts.tv_sec * 1000 + (uint64_t)ts.tv_nsec / 1000000; } static void use_temporary_dir(void) { char tmpdir_template[] = "./syzkaller.XXXXXX"; char* tmpdir = mkdtemp(tmpdir_template); if (!tmpdir) exit(1); if (chmod(tmpdir, 0777)) exit(1); if (chdir(tmpdir)) exit(1); } static bool write_file(const char* file, const char* what, ...) { char buf[1024]; va_list args; va_start(args, what); vsnprintf(buf, sizeof(buf), what, args); va_end(args); buf[sizeof(buf) - 1] = 0; int len = strlen(buf); int fd = open(file, O_WRONLY | O_CLOEXEC); if (fd == -1) return false; if (write(fd, buf, len) != len) { int err = errno; close(fd); errno = err; return false; } close(fd); return true; } static void setup_common() { if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 0)) { } } static void loop(); static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); setsid(); struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = (200 << 20); setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 32 << 20; setrlimit(RLIMIT_MEMLOCK, &rlim); rlim.rlim_cur = rlim.rlim_max = 136 << 20; setrlimit(RLIMIT_FSIZE, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_STACK, &rlim); rlim.rlim_cur = rlim.rlim_max = 0; setrlimit(RLIMIT_CORE, &rlim); rlim.rlim_cur = rlim.rlim_max = 256; setrlimit(RLIMIT_NOFILE, &rlim); if (unshare(CLONE_NEWNS)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(0x02000000)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } typedef struct { const char* name; const char* value; } sysctl_t; static const sysctl_t sysctls[] = { {"/proc/sys/kernel/shmmax", "16777216"}, {"/proc/sys/kernel/shmall", "536870912"}, {"/proc/sys/kernel/shmmni", "1024"}, {"/proc/sys/kernel/msgmax", "8192"}, {"/proc/sys/kernel/msgmni", "1024"}, {"/proc/sys/kernel/msgmnb", "1024"}, {"/proc/sys/kernel/sem", "1024 1048576 500 1024"}, }; unsigned i; for (i = 0; i < sizeof(sysctls) / sizeof(sysctls[0]); i++) write_file(sysctls[i].name, sysctls[i].value); } int wait_for_loop(int pid) { if (pid < 0) exit(1); int status = 0; while (waitpid(-1, &status, __WALL) != pid) { } return WEXITSTATUS(status); } static void drop_caps(void) { struct __user_cap_header_struct cap_hdr = {}; struct __user_cap_data_struct cap_data[2] = {}; cap_hdr.version = _LINUX_CAPABILITY_VERSION_3; cap_hdr.pid = getpid(); if (syscall(SYS_capget, &cap_hdr, &cap_data)) exit(1); const int drop = (1 << CAP_SYS_PTRACE) | (1 << CAP_SYS_NICE); cap_data[0].effective &= ~drop; cap_data[0].permitted &= ~drop; cap_data[0].inheritable &= ~drop; if (syscall(SYS_capset, &cap_hdr, &cap_data)) exit(1); } static int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid != 0) return wait_for_loop(pid); setup_common(); sandbox_common(); drop_caps(); if (unshare(CLONE_NEWNET)) { } loop(); exit(1); } #define FS_IOC_SETFLAGS _IOW('f', 2, long) static void remove_dir(const char* dir) { DIR* dp; struct dirent* ep; int iter = 0; retry: while (umount2(dir, MNT_DETACH) == 0) { } dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exit(1); } exit(1); } 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); while (umount2(filename, MNT_DETACH) == 0) { } struct stat st; if (lstat(filename, &st)) exit(1); if (S_ISDIR(st.st_mode)) { remove_dir(filename); continue; } int i; for (i = 0;; i++) { if (unlink(filename) == 0) break; if (errno == EPERM) { int fd = open(filename, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) close(fd); continue; } } if (errno == EROFS) { break; } if (errno != EBUSY || i > 100) exit(1); if (umount2(filename, MNT_DETACH)) exit(1); } } closedir(dp); int i; for (i = 0;; i++) { if (rmdir(dir) == 0) break; if (i < 100) { if (errno == EPERM) { int fd = open(dir, O_RDONLY); if (fd != -1) { long flags = 0; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) == 0) close(fd); continue; } } if (errno == EROFS) { break; } if (errno == EBUSY) { if (umount2(dir, MNT_DETACH)) exit(1); continue; } if (errno == ENOTEMPTY) { if (iter < 100) { iter++; goto retry; } } } exit(1); } } static void kill_and_wait(int pid, int* status) { kill(-pid, SIGKILL); kill(pid, SIGKILL); int i; for (i = 0; i < 100; i++) { if (waitpid(-1, status, WNOHANG | __WALL) == pid) return; usleep(1000); } DIR* dir = opendir("/sys/fs/fuse/connections"); if (dir) { for (;;) { struct dirent* ent = readdir(dir); if (!ent) break; if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0) continue; char abort[300]; snprintf(abort, sizeof(abort), "/sys/fs/fuse/connections/%s/abort", ent->d_name); int fd = open(abort, O_WRONLY); if (fd == -1) { continue; } if (write(fd, abort, 1) < 0) { } close(fd); } closedir(dir); } else { } while (waitpid(-1, status, __WALL) != pid) { } } static void setup_test() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setpgrp(); write_file("/proc/self/oom_score_adj", "1000"); } static void close_fds() { int fd; for (fd = 3; fd < 30; fd++) close(fd); } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter; for (iter = 0;; iter++) { char cwdbuf[32]; sprintf(cwdbuf, "./%d", iter); if (mkdir(cwdbuf, 0777)) exit(1); int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { if (chdir(cwdbuf)) exit(1); setup_test(); execute_one(); close_fds(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; sleep_ms(1); if (current_time_ms() - start < 5 * 1000) continue; kill_and_wait(pid, &status); break; } remove_dir(cwdbuf); } } uint64_t r[1] = {0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; memcpy((void*)0x20000000, "./file0\000", 8); syscall(__NR_mkdir, 0x20000000, 0); memcpy((void*)0x200001c0, "./file0\000", 8); syscall(__NR_mount, 0x20000000, 0x200001c0, 0, 0x2001001, 0); memcpy((void*)0x200000c0, "./file0\000", 8); memcpy((void*)0x20000100, "./file0\000", 8); syscall(__NR_pivot_root, 0x200000c0, 0x20000100); *(uint64_t*)0x20000180 = 0; *(uint32_t*)0x20000188 = 0; *(uint64_t*)0x20000190 = 0x20000040; *(uint64_t*)0x20000040 = 0; *(uint64_t*)0x20000048 = 0; *(uint64_t*)0x20000198 = 1; *(uint64_t*)0x200001a0 = 0; *(uint64_t*)0x200001a8 = 0; *(uint32_t*)0x200001b0 = 0; syscall(__NR_sendmsg, -1, 0x20000180, 0); res = syscall(__NR_socket, 0xf, 3, 2); if (res != -1) r[0] = res; *(uint64_t*)0x200001c0 = 0x40000000; *(uint32_t*)0x200001c8 = 0; *(uint64_t*)0x200001d0 = 0x20000040; *(uint64_t*)0x20000040 = 0x20000400; memcpy((void*)0x20000400, "\x02\x03\x06\x09\x10\x00\x00\x00\x00\x00\x00\x4c\x9e\x00\x00\x00\x02" "\x00\x13\x00\x02\x00\x51\x66\x93\xe3\x46\x68\xdf\xf9\x00\x01\x05\x00" "\x06\x00\x20\x00\x00\x00\x0a\x00\x00\x00\x00\x00\x00\x00\x00\x05\x00" "\xe5\x00\x00\x07\x00\x00\x00\x1f\x00\x00\x00\x00\x00\x00\x03\x00\x00" "\x00\x00\x00\x00\x02\x00\x01\x00\xf5\x00\x00\x00\x00\x00\x00\x02\x00" "\x00\x00\x00\x05\x00\x05\x00\x00\x00\x00\x00\x0a\x00\x00\x00\x00\xf4" "\x8d\x00\x04\x00\x00\x00\x00\x00\x00\x00\x00\x17\x00\x00\x00\x00\xa3" "\x9f\xd3\xd0\x74\xe0\x7a\xdc\x57\xb3\x68\x07\xf3\x14\x4f\xf9\xe9\xe6" "\x00\xc6\xcd\x7f\x6f\xc1\xda\x05\xfb\xdf\xab\x5e\x32\xfb\xe1\xfe\xce" "\xe9\x9f\xac\xcb\x3f\x3e\x32\xd8\x16\x28\x0b\x92\xa4\xfb\x8b\xc8\x9a" "\x39\x03\x7a\x2b\x1a\xca\x15\x33\x04\xd3\xb5\xa4\xfc\xb6\x69\x3f\x7d" "\x7b\x24\xf7\x51\xb1\x3b\x04\x4e\xc0\xb7\xe3\xa5\x4f\x17\xb0\x43\x8c" "\x14\x42\xc5\xd8\xba\x54\x8e\xcd\x19\x44\x40\xe8\xc9\x08\x2c\x86\xd5" "\x2b\xb8\x42\xbc\x91\x9e\x6c\xdb\x97\x5f\x82\xfe\x23\x5c\x63\xff\x5d" "\x84\xc2\x2a\xdd\xdd\xb5\x16\x5a\xe1\x2e\xe7\x49\xec\x8b\x03\xd1\xf0" "\xbe\x5d\x09\xe1\x02\xda\x34\x50\x8e\x72\x7a\x01\x62\x7e\x9b\x33\x9b" "\xb9\x86\x1b\xee\xc0\xc7\x80\x65\x25\x13\x99\x07\x24\xde\x78\xff\xbb" "\x14\xf2\xf5\x18\xe9\x63\xb4\x27\xea\x3a\x08\x8e\xaa\x67\x1a\xc7\xe4" "\x1f\xd4\xe7\x12\x99\x2e\xc3\x5f\xad\xdc\x55\xbc\x63\x1a\x07\x45\xe8" "\x19\x51\x0e\x62\x81\x15\x00\x00\x00\xdc\x9d\x3c\x86\x42\x28\xc7\x68" "\x15\x9d\xcd\x5d\x19\x32\x36\xf0\x49\x8d\x47\x69\x3d\x9c\xed\xd0\x32" "\x47\x0e\xd9\x36\xfb\xa4\x00\x98\x47\xdf\x95\x9c\xbb\x8e\x97\x38\xf7" "\x32\xce\xa1\xf3\x4a\x9d\xd7\x3f\xdd\x24\x1d\x0d\xcd\xb5\x22\x20\x45" "\xc3\xc8\xfa\x80\x37\x15\x0b\xfe\xaf\x3b\x6a\x4c\xef\xc1\xb4\x5e\xd1" "\xdb\x31\xec\x8a\x0c\x42\x41\xbb\x09\xed\x2d\x17\xbb\x75\x72\xa1\xe6" "\xfc\x7c\xde\xc4\xab\xa9\x47\x1f\xad\x74\x28\x09\x9f\xbe\x5f\x8e\xc0" "\x7c\xbe\x94\xdf\xb9\x94\x8c\x41\x19\x64\x6b\x68\x5d\x25\xd2\xa1\x3f" "\xb4\x83\x1d\x84\xc2\x1e\x00\x07\x53\xcd\xa5\xfe\xb7\x3a\xf8", 474); *(uint64_t*)0x20000048 = 0x80; *(uint64_t*)0x200001d8 = 1; *(uint64_t*)0x200001e0 = 0; *(uint64_t*)0x200001e8 = 0; *(uint32_t*)0x200001f0 = 0; syscall(__NR_sendmsg, -1, 0x200001c0, 0); syscall(__NR_sendmmsg, r[0], 0x20000180, 0x400000000000002, 0); } int main(void) { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); for (procid = 0; procid < 6; procid++) { if (fork() == 0) { use_temporary_dir(); do_sandbox_none(); } } sleep(1000000); return 0; }