// https://syzkaller.appspot.com/bug?id=db41035b1d82f3ef1b7353a3605d2ac029eb99bc // 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 static unsigned long long procid; 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 void thread_start(void* (*fn)(void*), void* arg) { pthread_t th; pthread_attr_t attr; pthread_attr_init(&attr); pthread_attr_setstacksize(&attr, 128 << 10); int i = 0; for (; i < 100; i++) { if (pthread_create(&th, &attr, fn, arg) == 0) { pthread_attr_destroy(&attr); return; } if (errno == EAGAIN) { usleep(50); continue; } break; } exit(1); } typedef struct { int state; } event_t; static void event_init(event_t* ev) { ev->state = 0; } static void event_reset(event_t* ev) { ev->state = 0; } static void event_set(event_t* ev) { if (ev->state) exit(1); __atomic_store_n(&ev->state, 1, __ATOMIC_RELEASE); syscall(SYS_futex, &ev->state, FUTEX_WAKE | FUTEX_PRIVATE_FLAG, 1000000); } static void event_wait(event_t* ev) { while (!__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE)) syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, 0); } static int event_isset(event_t* ev) { return __atomic_load_n(&ev->state, __ATOMIC_ACQUIRE); } static int event_timedwait(event_t* ev, uint64_t timeout) { uint64_t start = current_time_ms(); uint64_t now = start; for (;;) { uint64_t remain = timeout - (now - start); struct timespec ts; ts.tv_sec = remain / 1000; ts.tv_nsec = (remain % 1000) * 1000 * 1000; syscall(SYS_futex, &ev->state, FUTEX_WAIT | FUTEX_PRIVATE_FLAG, 0, &ts); if (__atomic_load_n(&ev->state, __ATOMIC_ACQUIRE)) return 1; now = current_time_ms(); if (now - start > timeout) return 0; } } 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 long syz_memcpy_off(volatile long a0, volatile long a1, volatile long a2, volatile long a3, volatile long a4) { char* dest = (char*)a0; uint32_t dest_off = (uint32_t)a1; char* src = (char*)a2; uint32_t src_off = (uint32_t)a3; size_t n = (size_t)a4; return (long)memcpy(dest + dest_off, src + src_off, n); } 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"); } struct thread_t { int created, call; event_t ready, done; }; static struct thread_t threads[16]; static void execute_call(int call); static int running; static void* thr(void* arg) { struct thread_t* th = (struct thread_t*)arg; for (;;) { event_wait(&th->ready); event_reset(&th->ready); execute_call(th->call); __atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED); event_set(&th->done); } return 0; } static void execute_one(void) { if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } int i, call, thread; for (call = 0; call < 9; call++) { for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0])); thread++) { struct thread_t* th = &threads[thread]; if (!th->created) { th->created = 1; event_init(&th->ready); event_init(&th->done); event_set(&th->done); thread_start(thr, th); } if (!event_isset(&th->done)) continue; event_reset(&th->done); th->call = call; __atomic_fetch_add(&running, 1, __ATOMIC_RELAXED); event_set(&th->ready); event_timedwait(&th->done, 50); break; } } for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) sleep_ms(1); } 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 (;;) { sleep_ms(10); if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; if (current_time_ms() - start < 5000) continue; kill_and_wait(pid, &status); break; } } } uint64_t r[1] = {0x0}; void execute_call(int call) { intptr_t res = 0; switch (call) { case 0: // prlimit64 arguments: [ // pid: pid (resource) // res: rlimit_type = 0xe (8 bytes) // new: ptr[in, rlimit] { // rlimit { // soft: intptr = 0x8 (8 bytes) // hard: intptr = 0x8b (8 bytes) // } // } // old: nil // ] NONFAILING(*(uint64_t*)0x200000000140 = 8); NONFAILING(*(uint64_t*)0x200000000148 = 0x8b); syscall(__NR_prlimit64, /*pid=*/0, /*res=RLIMIT_RTPRIO*/ 0xeul, /*new=*/0x200000000140ul, /*old=*/0ul); break; case 1: // sched_setscheduler arguments: [ // pid: pid (resource) // policy: sched_policy = 0x1 (8 bytes) // prio: ptr[in, int32] { // int32 = 0x7 (4 bytes) // } // ] NONFAILING(*(uint32_t*)0x200000000080 = 7); syscall(__NR_sched_setscheduler, /*pid=*/0, /*policy=SCHED_FIFO*/ 1ul, /*prio=*/0x200000000080ul); break; case 2: // timer_create arguments: [ // id: clock_id = 0x0 (8 bytes) // ev: ptr[in, sigevent] { // sigevent { // val: const = 0x0 (8 bytes) // signo: int32 = 0x21 (4 bytes) // notify: sigev_notify = 0x2 (4 bytes) // u: union sigevent_u { // tid: pid (resource) // } // pad = 0x0 (32 bytes) // } // } // timerid: ptr[out, timerid] { // timerid (resource) // } // ] NONFAILING(*(uint64_t*)0x200000000200 = 0); NONFAILING(*(uint32_t*)0x200000000208 = 0x21); NONFAILING(*(uint32_t*)0x20000000020c = 2); NONFAILING(*(uint32_t*)0x200000000210 = -1); res = syscall(__NR_timer_create, /*id=*/0ul, /*ev=*/0x200000000200ul, /*timerid=*/0x200000000300ul); if (res != -1) NONFAILING(r[0] = *(uint32_t*)0x200000000300); break; case 3: // fcntl$lock arguments: [ // fd: fd (resource) // cmd: fcntl_lock = 0x6 (8 bytes) // lock: ptr[in, flock] { // flock { // type: flock_type = 0x0 (2 bytes) // whence: seek_whence = 0x0 (2 bytes) // pad = 0x0 (4 bytes) // start: intptr = 0x60d3 (8 bytes) // len: intptr = 0x5 (8 bytes) // pid: pid (resource) // pad = 0x0 (4 bytes) // } // } // ] NONFAILING(*(uint16_t*)0x200000000040 = 0); NONFAILING(*(uint16_t*)0x200000000042 = 0); NONFAILING(*(uint64_t*)0x200000000048 = 0x60d3); NONFAILING(*(uint64_t*)0x200000000050 = 5); NONFAILING(*(uint32_t*)0x200000000058 = 0); syscall(__NR_fcntl, /*fd=*/(intptr_t)-1, /*cmd=F_SETLK*/ 6ul, /*lock=*/0x200000000040ul); break; case 4: // mprotect arguments: [ // addr: VMA[0xf000] // len: len = 0xf000 (8 bytes) // prot: mmap_prot = 0x1 (8 bytes) // ] syscall(__NR_mprotect, /*addr=*/0x200000000000ul, /*len=*/0xf000ul, /*prot=PROT_READ*/ 1ul); break; case 5: // timer_settime arguments: [ // timerid: timerid (resource) // flags: timer_flags = 0x1 (8 bytes) // new: ptr[in, itimerspec] { // itimerspec { // interv: timespec { // sec: time_sec (resource) // nsec: time_nsec (resource) // } // value: timespec { // sec: time_sec (resource) // nsec: time_nsec (resource) // } // } // } // old: nil // ] NONFAILING(*(uint64_t*)0x200000000040 = 0); NONFAILING(*(uint64_t*)0x200000000048 = 0); NONFAILING(*(uint64_t*)0x200000000050 = 0); NONFAILING(*(uint64_t*)0x200000000058 = 0x989680); syscall(__NR_timer_settime, /*timerid=*/r[0], /*flags=TIMER_ABSTIME*/ 1ul, /*new=*/0x200000000040ul, /*old=*/0ul); break; case 6: // mmap arguments: [ // addr: VMA[0x3000] // len: len = 0x3000 (8 bytes) // prot: mmap_prot = 0x2 (8 bytes) // flags: mmap_flags = 0x5031 (8 bytes) // fd: fd (resource) // offset: intptr = 0xc2dcc000 (8 bytes) // ] syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x3000ul, /*prot=PROT_WRITE*/ 2ul, /*flags=MAP_NORESERVE|MAP_FIXED|MAP_EXECUTABLE|MAP_ANONYMOUS|0x1*/ 0x5031ul, /*fd=*/(intptr_t)-1, /*offset=*/0xc2dcc000ul); break; case 7: // syz_memcpy_off$IO_URING_METADATA_GENERIC arguments: [ // ring_ptr: ring_ptr (resource) // off: io_uring_offsets = 0x4 (8 bytes) // src: nil // src_off: const = 0x0 (8 bytes) // nbytes: const = 0x4 (8 bytes) // ] NONFAILING(syz_memcpy_off(/*ring_ptr=*/0, /*off=*/4, /*src=*/0, /*src_off=*/0, /*nbytes=*/4)); break; case 8: // sched_setscheduler arguments: [ // pid: pid (resource) // policy: sched_policy = 0x2 (8 bytes) // prio: nil // ] syscall(__NR_sched_setscheduler, /*pid=*/0, /*policy=SCHED_RR*/ 2ul, /*prio=*/0ul); break; } } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200001000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); const char* reason; (void)reason; install_segv_handler(); for (procid = 0; procid < 5; procid++) { if (fork() == 0) { loop(); } } sleep(1000000); return 0; }