// https://syzkaller.appspot.com/bug?id=321eb2675fce51a0ca2a864303889aff70621649 // 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 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 long syz_open_dev(volatile long a0, volatile long a1, volatile long a2) { if (a0 == 0xc || a0 == 0xb) { char buf[128]; sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1, (uint8_t)a2); return open(buf, O_RDWR, 0); } else { unsigned long nb = a1; char buf[1024]; char* hash; strncpy(buf, (char*)a0, sizeof(buf) - 1); buf[sizeof(buf) - 1] = 0; while ((hash = strchr(buf, '#'))) { *hash = '0' + (char)(nb % 10); nb /= 10; } return open(buf, a2 & ~O_CREAT, 0); } } #define FS_IOC_SETFLAGS _IOW('f', 2, long) static void remove_dir(const char* dir) { int iter = 0; DIR* dp = 0; const int umount_flags = MNT_FORCE | UMOUNT_NOFOLLOW; retry: while (umount2(dir, umount_flags) == 0) { } dp = opendir(dir); if (dp == NULL) { if (errno == EMFILE) { exit(1); } exit(1); } struct dirent* ep = 0; 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, umount_flags) == 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, umount_flags)) exit(1); } } closedir(dp); for (int 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, umount_flags)) 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); 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"); if (symlink("/dev/binderfs", "./binderfs")) { } } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter = 0; for (;; 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(); 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; } remove_dir(cwdbuf); } } uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } // syz_open_dev$tty1 arguments: [ // dev: const = 0xc (8 bytes) // major: const = 0x4 (8 bytes) // minor: intptr = 0x1 (8 bytes) // ] // returns fd_tty res = -1; NONFAILING(res = syz_open_dev(/*dev=*/0xc, /*major=*/4, /*minor=*/1)); if (res != -1) r[0] = res; // ioctl$KDSKBENT arguments: [ // fd: fd_tty (resource) // cmd: const = 0x4b47 (4 bytes) // arg: ptr[in, kbentry] { // kbentry { // table: int8 = 0x0 (1 bytes) // index: int8 = 0x7f (1 bytes) // value: int16 = 0x20f (2 bytes) // } // } // ] NONFAILING(*(uint8_t*)0x200000000080 = 0); NONFAILING(*(uint8_t*)0x200000000081 = 0x7f); NONFAILING(*(uint16_t*)0x200000000082 = 0x20f); syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0x4b47, /*arg=*/0x200000000080ul); // ioctl$EVIOCSFF arguments: [ // fd: fd_evdev (resource) // cmd: const = 0x40304580 (4 bytes) // arg: ptr[in, ff_effect] { // ff_effect { // type: ff_effect_type = 0xd309bedfc70f16ed (2 bytes) // id: int16 = 0x0 (2 bytes) // dir: int16 = 0x2 (2 bytes) // trigger: ff_trigger { // button: int16 = 0x0 (2 bytes) // interv: int16 = 0x1 (2 bytes) // } // replay: ff_replay { // len: int16 = 0x7f (2 bytes) // delay: int16 = 0x2 (2 bytes) // } // pad = 0x0 (2 bytes) // u: union ff_effect_u { // cond: array[ff_condition_effect] { // ff_condition_effect { // rsatur: int16 = 0x22f (2 bytes) // lsatur: int16 = 0x3ff (2 bytes) // rcoeff: int16 = 0x404 (2 bytes) // lcoeff: int16 = 0x4 (2 bytes) // dead: int16 = 0x1 (2 bytes) // center: int16 = 0xa (2 bytes) // } // ff_condition_effect { // rsatur: int16 = 0x0 (2 bytes) // lsatur: int16 = 0xa0 (2 bytes) // rcoeff: int16 = 0x1 (2 bytes) // lcoeff: int16 = 0x4 (2 bytes) // dead: int16 = 0x7ff (2 bytes) // center: int16 = 0xff01 (2 bytes) // } // } // } // } // } // ] NONFAILING(*(uint16_t*)0x2000000006c0 = 0x16ed); NONFAILING(*(uint16_t*)0x2000000006c2 = 0); NONFAILING(*(uint16_t*)0x2000000006c4 = 2); NONFAILING(*(uint16_t*)0x2000000006c6 = 0); NONFAILING(*(uint16_t*)0x2000000006c8 = 1); NONFAILING(*(uint16_t*)0x2000000006ca = 0x7f); NONFAILING(*(uint16_t*)0x2000000006cc = 2); NONFAILING(*(uint16_t*)0x2000000006d0 = 0x22f); NONFAILING(*(uint16_t*)0x2000000006d2 = 0x3ff); NONFAILING(*(uint16_t*)0x2000000006d4 = 0x404); NONFAILING(*(uint16_t*)0x2000000006d6 = 4); NONFAILING(*(uint16_t*)0x2000000006d8 = 1); NONFAILING(*(uint16_t*)0x2000000006da = 0xa); NONFAILING(*(uint16_t*)0x2000000006dc = 0); NONFAILING(*(uint16_t*)0x2000000006de = 0xa0); NONFAILING(*(uint16_t*)0x2000000006e0 = 1); NONFAILING(*(uint16_t*)0x2000000006e2 = 4); NONFAILING(*(uint16_t*)0x2000000006e4 = 0x7ff); NONFAILING(*(uint16_t*)0x2000000006e6 = 0xff01); syscall(__NR_ioctl, /*fd=*/(intptr_t)-1, /*cmd=*/0x40304580, /*arg=*/0x2000000006c0ul); // syz_open_dev$evdev arguments: [ // dev: ptr[in, buffer] { // buffer: {2f 64 65 76 2f 69 6e 70 75 74 2f 65 76 65 6e 74 23 00} // (length 0x12) // } // id: intptr = 0x2 (8 bytes) // flags: open_flags = 0x822b01 (8 bytes) // ] // returns fd_evdev NONFAILING(memcpy((void*)0x2000000000c0, "/dev/input/event#\000", 18)); res = -1; NONFAILING( res = syz_open_dev( /*dev=*/0x2000000000c0, /*id=*/2, /*flags=O_TRUNC|O_NONBLOCK|O_NOFOLLOW|O_NOCTTY|FASYNC|O_WRONLY|0x800000*/ 0x822b01)); if (res != -1) r[1] = res; // write$char_usb arguments: [ // fd: fd_char_usb (resource) // buf: ptr[in, buffer] { // buffer: {e2} (length 0x1) // } // count: len = 0x12d8 (8 bytes) // ] NONFAILING(memset((void*)0x200000000040, 226, 1)); syscall(__NR_write, /*fd=*/r[1], /*buf=*/0x200000000040ul, /*count=*/0x12d8ul); // openat$ptmx arguments: [ // fd: const = 0xffffffffffffff9c (8 bytes) // file: nil // flags: open_flags = 0x0 (4 bytes) // mode: const = 0x0 (2 bytes) // ] // returns fd_tty syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0ul, /*flags=*/0, /*mode=*/0); } 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) { use_temporary_dir(); loop(); } } sleep(1000000); return 0; }