// https://syzkaller.appspot.com/bug?id=848446dc184d15d80ae51364da95fba01f04b127 // 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_fsconfig #define __NR_fsconfig 431 #endif #ifndef __NR_mmap #define __NR_mmap 222 #endif #ifndef __NR_write #define __NR_write 64 #endif static unsigned long long procid; 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 long syz_open_procfs(volatile long a0, volatile long a1) { char buf[128]; memset(buf, 0, sizeof(buf)); if (a0 == 0) { snprintf(buf, sizeof(buf), "/proc/self/%s", (char*)a1); } else if (a0 == -1) { snprintf(buf, sizeof(buf), "/proc/thread-self/%s", (char*)a1); } else { snprintf(buf, sizeof(buf), "/proc/self/task/%d/%s", (int)a0, (char*)a1); } int fd = open(buf, O_RDWR); if (fd == -1) fd = open(buf, O_RDONLY); 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 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] = {0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } // fsconfig$FSCONFIG_SET_BINARY arguments: [ // fd: fd_fscontext (resource) // cmd: const = 0x2 (8 bytes) // key: ptr[in, buffer] { // buffer: {6d 65 6d 00 ff 45 65 76 f2 72 f1 18 1d b9 00 79 5f 68 75 67 // 24 08 6f 2d 03 51 60 5d 6f 8c 72 9d 5f 65 74 6c f9 dd 07 ad 5c 48 e9 // 34 08 2c 48 bf} (length 0x30) // } // value: nil // aux: bytesize = 0x0 (8 bytes) // ] memcpy((void*)0x20000040, "mem\000\377Eev\362r\361\030\035\271\000y_hug$\bo-\003Q`]o\214r\235_" "etl\371\335\a\255\\H\3514\b,H\277", 48); syscall(__NR_fsconfig, /*fd=*/(intptr_t)-1, /*cmd=*/2ul, /*key=*/0x20000040ul, /*value=*/0ul, /*aux=*/0ul); // syz_open_procfs arguments: [ // pid: pid (resource) // file: ptr[in, buffer] { // buffer: {} (length 0x0) // } // ] // returns fd res = -1; res = syz_open_procfs(/*pid=*/0, /*file=*/0x20000040); if (res != -1) r[0] = res; // write$tun arguments: [ // fd: fd_tun (resource) // buf: nil // count: len = 0xfffffd68 (8 bytes) // ] syscall(__NR_write, /*fd=*/r[0], /*buf=*/0ul, /*count=*/0xfffffd68ul); } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000, /*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=*/0x21000000ul, /*len=*/0x1000, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); const char* reason; (void)reason; for (procid = 0; procid < 4; procid++) { if (fork() == 0) { loop(); } } sleep(1000000); return 0; }