// https://syzkaller.appspot.com/bug?id=5e0f3b124fae1a6591407853f9a098d63a318f97 // 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 #ifndef __NR_dup #define __NR_dup 23 #endif #ifndef __NR_mkdirat #define __NR_mkdirat 34 #endif #ifndef __NR_mmap #define __NR_mmap 222 #endif #ifndef __NR_mount #define __NR_mount 40 #endif #ifndef __NR_pipe2 #define __NR_pipe2 59 #endif #ifndef __NR_setxattr #define __NR_setxattr 5 #endif #ifndef __NR_write #define __NR_write 64 #endif static __thread int clone_ongoing; static __thread int skip_segv; static __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* ctx) { if (__atomic_load_n(&clone_ongoing, __ATOMIC_RELAXED) != 0) { exit(sig); } uintptr_t addr = (uintptr_t)info->si_addr; const uintptr_t prog_start = 1 << 20; const uintptr_t prog_end = 100 << 20; int skip = __atomic_load_n(&skip_segv, __ATOMIC_RELAXED) != 0; int valid = addr < prog_start || addr > prog_end; if (skip && valid) { _longjmp(segv_env, 1); } exit(sig); } static void install_segv_handler(void) { struct sigaction sa; memset(&sa, 0, sizeof(sa)); sa.sa_handler = SIG_IGN; syscall(SYS_rt_sigaction, 0x20, &sa, NULL, 8); syscall(SYS_rt_sigaction, 0x21, &sa, NULL, 8); memset(&sa, 0, sizeof(sa)); sa.sa_sigaction = segv_handler; sa.sa_flags = SA_NODEFER | SA_SIGINFO; sigaction(SIGSEGV, &sa, NULL); sigaction(SIGBUS, &sa, NULL); } #define NONFAILING(...) \ ({ \ int ok = 1; \ __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); \ if (_setjmp(segv_env) == 0) { \ __VA_ARGS__; \ } else \ ok = 0; \ __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); \ ok; \ }) 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 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 int inject_fault(int nth) { int fd; fd = open("/proc/thread-self/fail-nth", O_RDWR); if (fd == -1) exit(1); char buf[16]; sprintf(buf, "%d", nth); if (write(fd, buf, strlen(buf)) != (ssize_t)strlen(buf)) exit(1); return fd; } static void kill_and_wait(int pid, int* status) { kill(-pid, SIGKILL); kill(pid, SIGKILL); for (int 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 setup_fault() { static struct { const char* file; const char* val; bool fatal; } files[] = { {"/sys/kernel/debug/failslab/ignore-gfp-wait", "N", true}, {"/sys/kernel/debug/fail_futex/ignore-private", "N", false}, {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-highmem", "N", false}, {"/sys/kernel/debug/fail_page_alloc/ignore-gfp-wait", "N", false}, {"/sys/kernel/debug/fail_page_alloc/min-order", "0", false}, }; unsigned i; for (i = 0; i < sizeof(files) / sizeof(files[0]); i++) { if (!write_file(files[i].file, files[i].val)) { if (files[i].fatal) exit(1); } } } static void setup_sysctl() { char mypid[32]; snprintf(mypid, sizeof(mypid), "%d", getpid()); struct { const char* name; const char* data; } files[] = { {"/proc/sys/kernel/hung_task_check_interval_secs", "20"}, {"/proc/sys/net/core/bpf_jit_kallsyms", "1"}, {"/proc/sys/net/core/bpf_jit_harden", "0"}, {"/proc/sys/kernel/kptr_restrict", "0"}, {"/proc/sys/kernel/softlockup_all_cpu_backtrace", "1"}, {"/proc/sys/fs/mount-max", "100"}, {"/proc/sys/vm/oom_dump_tasks", "0"}, {"/proc/sys/debug/exception-trace", "0"}, {"/proc/sys/kernel/printk", "7 4 1 3"}, {"/proc/sys/kernel/keys/gc_delay", "1"}, {"/proc/sys/vm/oom_kill_allocating_task", "1"}, {"/proc/sys/kernel/ctrl-alt-del", "0"}, {"/proc/sys/kernel/cad_pid", mypid}, }; for (size_t i = 0; i < sizeof(files) / sizeof(files[0]); i++) { if (!write_file(files[i].name, files[i].data)) printf("write to %s failed: %s\n", files[i].name, strerror(errno)); } } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter = 0; for (;; iter++) { int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { setup_test(); execute_one(); 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 < 5000) continue; kill_and_wait(pid, &status); break; } } } uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; NONFAILING(memcpy((void*)0x20002040, "./file0\000", 8)); syscall(__NR_mkdirat, 0xffffff9c, 0x20002040ul, 0ul); res = syscall(__NR_pipe2, 0x20000240ul, 0ul); if (res != -1) { NONFAILING(r[0] = *(uint32_t*)0x20000240); NONFAILING(r[1] = *(uint32_t*)0x20000244); } NONFAILING(memcpy((void*)0x20000080, "\x15\x00\x00\x00\x65\xff\xff\x09\x7b\x00\x00\x08\x00\x39" "\x50\x32\x30\x30\x30\x2e\x4c", 21)); syscall(__NR_write, r[1], 0x20000080ul, 0x15ul); res = syscall(__NR_dup, r[1]); if (res != -1) r[2] = res; NONFAILING(*(uint32_t*)0x20000100 = 0x18); NONFAILING(*(uint32_t*)0x20000104 = 0); NONFAILING(*(uint64_t*)0x20000108 = 0); NONFAILING(*(uint64_t*)0x20000110 = 0); syscall(__NR_write, r[2], 0x20000100ul, 0x18ul); NONFAILING(*(uint32_t*)0x200000c0 = 0x14c); NONFAILING(*(uint32_t*)0x200000c4 = 5); NONFAILING(*(uint64_t*)0x200000c8 = 0); NONFAILING(*(uint64_t*)0x200000d0 = 0); NONFAILING(*(uint64_t*)0x200000d8 = 0); NONFAILING(*(uint64_t*)0x200000e0 = 0); NONFAILING(*(uint32_t*)0x200000e8 = 0); NONFAILING(*(uint32_t*)0x200000ec = 0); syscall(__NR_write, r[2], 0x200000c0ul, 0x137ul); NONFAILING(memcpy((void*)0x20000040, "./file0\000", 8)); NONFAILING(memcpy((void*)0x20000b80, "9p\000", 3)); NONFAILING(memcpy((void*)0x20000400, "trans=fd,", 9)); NONFAILING(memcpy((void*)0x20000409, "rfdno", 5)); NONFAILING(*(uint8_t*)0x2000040e = 0x3d); NONFAILING(sprintf((char*)0x2000040f, "0x%016llx", (long long)r[0])); NONFAILING(*(uint8_t*)0x20000421 = 0x2c); NONFAILING(memcpy((void*)0x20000422, "wfdno", 5)); NONFAILING(*(uint8_t*)0x20000427 = 0x3d); NONFAILING(sprintf((char*)0x20000428, "0x%016llx", (long long)r[2])); NONFAILING(*(uint8_t*)0x2000043a = 0x2c); NONFAILING(*(uint8_t*)0x2000043b = 0); syscall(__NR_mount, 0ul, 0x20000040ul, 0x20000b80ul, 0ul, 0x20000400ul); NONFAILING(memcpy((void*)0x20000000, "./file0\000", 8)); NONFAILING(memcpy((void*)0x20000140, "trusted.overlay.upper\000", 22)); NONFAILING(*(uint8_t*)0x20000180 = 0); NONFAILING(*(uint8_t*)0x20000181 = 0xfb); NONFAILING(*(uint8_t*)0x20000182 = 0x15); NONFAILING(*(uint8_t*)0x20000183 = 0); NONFAILING(*(uint8_t*)0x20000184 = 0); NONFAILING(memcpy( (void*)0x20000185, "\xb1\x09\x39\x5c\xd6\x57\x80\x6d\xa7\x58\x28\x4a\xab\x90\xfc\x1b", 16)); inject_fault(24); syscall(__NR_setxattr, 0x20000000ul, 0x20000140ul, 0x20000180ul, 0x7af1ul, 0ul); } 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); setup_sysctl(); setup_fault(); install_segv_handler(); loop(); return 0; }