// https://syzkaller.appspot.com/bug?id=8a22955cd068cf454dd8062d24e826c72b1c4542 // 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 #ifndef SYS___specialfd #define SYS___specialfd 577 #endif #ifndef SYS_inotify_add_watch_at #define SYS_inotify_add_watch_at 593 #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 (sig == SIGBUS) valid = 1; 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_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 kill_and_wait(int pid, int* status) { kill(pid, SIGKILL); while (waitpid(-1, status, 0) != pid) { } } 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 execute_one(void); #define WAIT_FLAGS 0 static void loop(void) { int iter = 0; for (;; iter++) { int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { 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] = {0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } // openat$evdev arguments: [ // fd: const = 0xffffffffffffff9c (8 bytes) // file: ptr[in, buffer] { // buffer: {2f 64 65 76 2f 69 6e 70 75 74 2f 65 76 65 6e 74 4e 00} // (length 0x12) // } // flags: open_flags = 0x100 (8 bytes) // mode: const = 0x0 (8 bytes) // ] // returns fd_evdev NONFAILING(memcpy((void*)0x200000000040, "/dev/input/eventN\000", 18)); syscall(SYS_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x200000000040ul, /*flags=O_NOFOLLOW*/ 0x100ul, /*mode=*/0ul); // kqueue arguments: [ // ] // returns kqueue syscall(SYS_kqueue); // socket$unix arguments: [ // domain: const = 0x1 (8 bytes) // type: unix_socket_type = 0x5 (8 bytes) // proto: const = 0x0 (1 bytes) // ] // returns sock_unix syscall(SYS_socket, /*domain=*/1ul, /*type=SOCK_SEQPACKET*/ 5ul, /*proto=*/0); // kevent arguments: [ // kqueue: kqueue (resource) // changelist: ptr[in, array[kevent]] { // array[kevent] { // kevent { // ident: intptr = 0x7 (8 bytes) // filter: filters = 0xfffffffffffffffe (2 bytes) // flags: evflags = 0x40c3 (2 bytes) // fflags: fflags = 0x40000003 (4 bytes) // data: int64 = 0x7 (8 bytes) // udata: intptr = 0x4e6 (8 bytes) // ext: array[int64] { // int64 = 0x9 (8 bytes) // int64 = 0x4 (8 bytes) // int64 = 0x3 (8 bytes) // int64 = 0x8 (8 bytes) // } // } // } // } // nchanges: len = 0x1 (8 bytes) // eventlist: nil // nevents: len = 0x0 (8 bytes) // timeout: nil // ] NONFAILING(*(uint64_t*)0x200000000500 = 7); NONFAILING(*(uint16_t*)0x200000000508 = 0xfffe); NONFAILING(*(uint16_t*)0x20000000050a = 0x40c3); NONFAILING(*(uint32_t*)0x20000000050c = 0x40000003); NONFAILING(*(uint64_t*)0x200000000510 = 7); NONFAILING(*(uint64_t*)0x200000000518 = 0x4e6); NONFAILING(*(uint64_t*)0x200000000520 = 9); NONFAILING(*(uint64_t*)0x200000000528 = 4); NONFAILING(*(uint64_t*)0x200000000530 = 3); NONFAILING(*(uint64_t*)0x200000000538 = 8); syscall(SYS_kevent, /*kqueue=*/(intptr_t)-1, /*changelist=*/0x200000000500ul, /*nchanges=*/1ul, /*eventlist=*/0ul, /*nevents=*/0ul, /*timeout=*/0ul); // kevent arguments: [ // kqueue: kqueue (resource) // changelist: nil // nchanges: len = 0x0 (8 bytes) // eventlist: nil // nevents: len = 0x0 (8 bytes) // timeout: nil // ] syscall(SYS_kevent, /*kqueue=*/(intptr_t)-1, /*changelist=*/0ul, /*nchanges=*/0ul, /*eventlist=*/0ul, /*nevents=*/0ul, /*timeout=*/0ul); // mprotect arguments: [ // addr: VMA[0x2000] // len: len = 0x2000 (8 bytes) // prot: mmap_prot = 0x5 (8 bytes) // ] syscall(SYS_mprotect, /*addr=*/0x200000000000ul, /*len=*/0x2000ul, /*prot=PROT_READ|PROT_EXEC*/ 5ul); // symlink arguments: [ // old: ptr[in, buffer] { // buffer: {2e 00} (length 0x2) // } // new: ptr[in, buffer] { // buffer: {2e 2f 66 69 6c 65 30 00} (length 0x8) // } // ] NONFAILING(memcpy((void*)0x200000000000, ".\000", 2)); NONFAILING(memcpy((void*)0x200000000040, "./file0\000", 8)); syscall(SYS_symlink, /*old=*/0x200000000000ul, /*new=*/0x200000000040ul); // __specialfd$inotify arguments: [ // type: const = 0x2 (8 bytes) // req: ptr[in, specialfd_inotify] { // specialfd_inotify { // flags: inotify_flags = 0x0 (4 bytes) // } // } // len: len = 0x4 (8 bytes) // ] // returns fd_inotify NONFAILING(*(uint32_t*)0x200000000180 = 0); res = syscall(SYS___specialfd, /*type=*/2ul, /*req=*/0x200000000180ul, /*len=*/4ul); if (res != -1) r[0] = res; // inotify_add_watch_at arguments: [ // fd: fd_inotify (resource) // dfd: fd_dir (resource) // file: ptr[in, buffer] { // buffer: {2e 2f 66 69 6c 65 30 61 61 61 61 61 61 61 61 61 61 61 61 61 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 // 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 61 2f 66 // 69 6c 65 30 00} (length 0xff) // } // mask: inotify_mask = 0x82000204 (8 bytes) // ] // returns inotifydesc NONFAILING( memcpy((void*)0x200000000040, "./" "file0aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa" "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/file0\000", 255)); syscall(SYS_inotify_add_watch_at, /*fd=*/r[0], /*dfd=*/(intptr_t)-1, /*file=*/0x200000000040ul, /*mask=IN_ONESHOT|IN_DONT_FOLLOW|IN_DELETE|IN_ATTRIB*/ 0x82000204ul); // unlink arguments: [ // path: ptr[in, buffer] { // buffer: {2e 2f 66 69 6c 65 30 00} (length 0x8) // } // ] NONFAILING(memcpy((void*)0x200000000040, "./file0\000", 8)); syscall(SYS_unlink, /*path=*/0x200000000040ul); } int main(void) { syscall(SYS_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul, /*prot=PROT_WRITE|PROT_READ|PROT_EXEC*/ 7ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x1012ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); const char* reason; (void)reason; install_segv_handler(); loop(); return 0; }