// https://syzkaller.appspot.com/bug?id=22605650ad0a2d7f7978dd89c7199b721ea5c8d4 // 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 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 const char* setup_fault() { int fd = open("/proc/self/make-it-fail", O_WRONLY); if (fd == -1) return "CONFIG_FAULT_INJECTION is not enabled"; close(fd); fd = open("/proc/thread-self/fail-nth", O_WRONLY); if (fd == -1) return "kernel does not have systematic fault injection support"; close(fd); 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) return "failed to write fault injection file"; } } return NULL; } 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[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } // openat arguments: [ // fd: fd_dir (resource) // file: ptr[in, buffer] { // buffer: {2e 2f 66 69 6c 65 30 00} (length 0x8) // } // flags: open_flags = 0x42 (4 bytes) // mode: open_mode = 0x1ff (2 bytes) // ] // returns fd memcpy((void*)0x200000000000, "./file0\000", 8); res = syscall( __NR_openat, /*fd=*/0xffffff9c, /*file=*/0x200000000000ul, /*flags=O_CREAT|O_RDWR*/ 0x42, /*mode=S_IXOTH|S_IWOTH|S_IROTH|S_IXGRP|S_IWGRP|S_IRGRP|S_IXUSR|S_IWUSR|0x100*/ 0x1ff); if (res != -1) r[0] = res; // mmap arguments: [ // addr: VMA[0x1000] // len: len = 0x1000 (4 bytes) // prot: mmap_prot = 0x5 (8 bytes) // flags: mmap_flags = 0x12 (8 bytes) // fd: fd (resource) // offset: intptr = 0x0 (8 bytes) // ] syscall(__NR_mmap, /*addr=*/0x200000800000ul, /*len=*/0x1000, /*prot=PROT_READ|PROT_EXEC*/ 5ul, /*flags=MAP_FIXED|MAP_PRIVATE*/ 0x12ul, /*fd=*/r[0], /*offset=*/0ul); // mkdirat arguments: [ // fd: fd_dir (resource) // path: ptr[in, buffer] { // buffer: {2e 2f 74 72 61 63 69 6e 67 00} (length 0xa) // } // mode: open_mode = 0x1ff (8 bytes) // ] memcpy((void*)0x200000000080, "./tracing\000", 10); syscall( __NR_mkdirat, /*fd=*/0xffffff9c, /*path=*/0x200000000080ul, /*mode=S_IXOTH|S_IWOTH|S_IROTH|S_IXGRP|S_IWGRP|S_IRGRP|S_IXUSR|S_IWUSR|0x100*/ 0x1fful); // mount arguments: [ // src: nil // dst: ptr[in, buffer] { // buffer: {2e 2f 74 72 61 63 69 6e 67 00} (length 0xa) // } // type: ptr[in, buffer] { // buffer: {74 72 61 63 65 66 73 00} (length 0x8) // } // flags: mount_flags = 0x0 (8 bytes) // data: nil // ] memcpy((void*)0x2000000000c0, "./tracing\000", 10); memcpy((void*)0x200000000100, "tracefs\000", 8); syscall(__NR_mount, /*src=*/0ul, /*dst=*/0x2000000000c0ul, /*type=*/0x200000000100ul, /*flags=*/0ul, /*data=*/0ul); // openat arguments: [ // fd: fd_dir (resource) // file: ptr[in, buffer] { // buffer: {2e 2f 74 72 61 63 69 6e 67 2f 75 70 72 6f 62 65 5f 65 76 65 // 6e 74 73 00} (length 0x18) // } // flags: open_flags = 0x401 (4 bytes) // mode: open_mode = 0x0 (2 bytes) // ] // returns fd memcpy((void*)0x200000000140, "./tracing/uprobe_events\000", 24); res = syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x200000000140ul, /*flags=O_APPEND|O_WRONLY*/ 0x401, /*mode=*/0); if (res != -1) r[1] = res; // write arguments: [ // fd: fd (resource) // buf: ptr[in, buffer] { // buffer: {70 3a 73 2f 70 20 2e 2f 66 69 6c 65 30 3a 30} (length 0xf) // } // count: len = 0xf (8 bytes) // ] memcpy((void*)0x200000000180, "p:s/p ./file0:0", 15); syscall(__NR_write, /*fd=*/r[1], /*buf=*/0x200000000180ul, /*count=*/0xful); // openat arguments: [ // fd: fd_dir (resource) // file: ptr[in, buffer] { // buffer: {2e 2f 74 72 61 63 69 6e 67 2f 65 76 65 6e 74 73 2f 73 2f 70 // 2f 65 6e 61 62 6c 65 00} (length 0x1c) // } // flags: open_flags = 0x1 (4 bytes) // mode: open_mode = 0x0 (2 bytes) // ] // returns fd memcpy((void*)0x200000000200, "./tracing/events/s/p/enable\000", 28); res = syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x200000000200ul, /*flags=O_WRONLY*/ 1, /*mode=*/0); if (res != -1) r[2] = res; // write arguments: [ // fd: fd (resource) // buf: ptr[in, buffer] { // buffer: {31} (length 0x1) // } // count: len = 0x1 (8 bytes) // ] memset((void*)0x200000000240, 49, 1); inject_fault(2); syscall(__NR_write, /*fd=*/r[2], /*buf=*/0x200000000240ul, /*count=*/1ul); } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*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=*/0x200001000000ul, /*len=*/0x1000, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); const char* reason; (void)reason; if ((reason = setup_fault())) { fprintf(stderr, "reproducer setup failed: fault injection: %s\n", reason); exit(1); } loop(); return 0; }