// https://syzkaller.appspot.com/bug?id=02a32f98a4e3b5a2ed6929aabdd28dd1618b9c03 // 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 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); } #define BITMASK(bf_off, bf_len) (((1ull << (bf_len)) - 1) << (bf_off)) #define STORE_BY_BITMASK(type, htobe, addr, val, bf_off, bf_len) \ *(type*)(addr) = \ htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) | \ (((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len)))) 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 int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid != 0) return wait_for_loop(pid); setup_common(); sandbox_common(); 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); } } #ifndef __NR_bpf #define __NR_bpf 321 #endif uint64_t r[1] = {0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; *(uint32_t*)0x20caefb8 = 0x16; *(uint32_t*)0x20caefbc = 3; *(uint64_t*)0x20caefc0 = 0x2045c000; *(uint8_t*)0x2045c000 = 0x85; STORE_BY_BITMASK(uint8_t, , 0x2045c001, 0, 0, 4); STORE_BY_BITMASK(uint8_t, , 0x2045c001, 0, 4, 4); *(uint16_t*)0x2045c002 = 0; *(uint32_t*)0x2045c004 = 7; *(uint8_t*)0x2045c008 = 0x4c; *(uint8_t*)0x2045c009 = 0; *(uint16_t*)0x2045c00a = 0; *(uint32_t*)0x2045c00c = 0; *(uint8_t*)0x2045c010 = 0x95; *(uint8_t*)0x2045c011 = 0; *(uint16_t*)0x2045c012 = 0; *(uint32_t*)0x2045c014 = 0; *(uint64_t*)0x20caefc8 = 0x20281ffc; memcpy((void*)0x20281ffc, "G\377L\000", 4); *(uint32_t*)0x20caefd0 = 0; *(uint32_t*)0x20caefd4 = 0; *(uint64_t*)0x20caefd8 = 0; *(uint32_t*)0x20caefe0 = 0; *(uint32_t*)0x20caefe4 = 0; *(uint8_t*)0x20caefe8 = 0; *(uint8_t*)0x20caefe9 = 0; *(uint8_t*)0x20caefea = 0; *(uint8_t*)0x20caefeb = 0; *(uint8_t*)0x20caefec = 0; *(uint8_t*)0x20caefed = 0; *(uint8_t*)0x20caefee = 0; *(uint8_t*)0x20caefef = 0; *(uint8_t*)0x20caeff0 = 0; *(uint8_t*)0x20caeff1 = 0; *(uint8_t*)0x20caeff2 = 0; *(uint8_t*)0x20caeff3 = 0; *(uint8_t*)0x20caeff4 = 0; *(uint8_t*)0x20caeff5 = 0; *(uint8_t*)0x20caeff6 = 0; *(uint8_t*)0x20caeff7 = 0; *(uint32_t*)0x20caeff8 = 0; *(uint32_t*)0x20caeffc = 0; *(uint32_t*)0x20caf000 = -1; *(uint32_t*)0x20caf004 = 8; *(uint64_t*)0x20caf008 = 0x20000000; *(uint32_t*)0x20000000 = 0; *(uint32_t*)0x20000004 = 0; *(uint32_t*)0x20caf010 = 0; *(uint32_t*)0x20caf014 = 0x10; *(uint64_t*)0x20caf018 = 0x20000000; *(uint32_t*)0x20000000 = 0; *(uint32_t*)0x20000004 = 0; *(uint32_t*)0x20000008 = 0; *(uint32_t*)0x2000000c = 0; *(uint32_t*)0x20caf020 = 0; res = syscall(__NR_bpf, 5, 0x20caefb8, 0x48); if (res != -1) r[0] = res; *(uint32_t*)0x200001c0 = r[0]; *(uint32_t*)0x200001c4 = 5; *(uint32_t*)0x200001c8 = 0xe; *(uint32_t*)0x200001cc = 0; *(uint64_t*)0x200001d0 = 0x20000080; memcpy((void*)0x20000080, "\xad\x46\xeb\xbb\xff\x37\xf7\x24\xed\x8c\x00\xf5\x79\xbf", 14); *(uint64_t*)0x200001d8 = 0; *(uint32_t*)0x200001e0 = 0x8000; *(uint32_t*)0x200001e4 = 0; syscall(__NR_bpf, 0xa, 0x200001c0, 0x28); } int main(void) { syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); use_temporary_dir(); do_sandbox_none(); return 0; }