// https://syzkaller.appspot.com/bug?id=753b102b53c456497cdc259cb30f2a19823c64fc // 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_mkdirat #define __NR_mkdirat 34 #endif #ifndef __NR_mmap #define __NR_mmap 222 #endif #ifndef __NR_mount #define __NR_mount 40 #endif #ifndef __NR_openat #define __NR_openat 56 #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 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)) { } // mkdirat arguments: [ // fd: fd_dir (resource) // path: ptr[in, buffer] { // buffer: {2e 2f 70 72 6f 63 00} (length 0x7) // } // mode: open_mode = 0x1ff (8 bytes) // ] memcpy((void*)0x20000000, "./proc\000", 7); syscall( __NR_mkdirat, /*fd=*/0xffffff9c, /*path=*/0x20000000ul, /*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 70 72 6f 63 00} (length 0x7) // } // type: ptr[in, buffer] { // buffer: {70 72 6f 63 00} (length 0x5) // } // flags: mount_flags = 0x0 (8 bytes) // data: nil // ] memcpy((void*)0x20000000, "./proc\000", 7); memcpy((void*)0x20000010, "proc\000", 5); syscall(__NR_mount, /*src=*/0ul, /*dst=*/0x20000000ul, /*type=*/0x20000010ul, /*flags=*/0ul, /*data=*/0ul); // openat arguments: [ // fd: fd_dir (resource) // file: ptr[in, buffer] { // buffer: {2e 2f 70 72 6f 63 2f 6e 65 74 2f 61 66 73 2f 63 65 6c 6c 73 // 00} (length 0x15) // } // flags: open_flags = 0x2 (4 bytes) // mode: open_mode = 0x0 (2 bytes) // ] // returns fd memcpy((void*)0x20000020, "./proc/net/afs/cells\000", 21); res = syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x20000020ul, /*flags=O_RDWR*/ 2, /*mode=*/0); if (res != -1) r[0] = res; // write arguments: [ // fd: fd (resource) // buf: ptr[in, buffer] { // buffer: {61 64 64 20 73 79 7a 30 20 3a 3a 31 0a} (length 0xd) // } // count: len = 0xd (8 bytes) // ] memcpy((void*)0x20000040, "add syz0 ::1\n", 13); syscall(__NR_write, /*fd=*/r[0], /*buf=*/0x20000040ul, /*count=*/0xdul); // mkdirat arguments: [ // fd: fd_dir (resource) // path: ptr[in, buffer] { // buffer: {2e 2f 66 69 6c 65 30 00} (length 0x8) // } // mode: open_mode = 0x1ff (8 bytes) // ] memcpy((void*)0x20000b00, "./file0\000", 8); syscall( __NR_mkdirat, /*fd=*/0xffffff9c, /*path=*/0x20000b00ul, /*mode=S_IXOTH|S_IWOTH|S_IROTH|S_IXGRP|S_IWGRP|S_IRGRP|S_IXUSR|S_IWUSR|0x100*/ 0x1fful); // mount$afs arguments: [ // src: ptr[in, afs_source] { // union afs_source { // cell: afs_cell_source { // prefix: afs_cell_prefix = 0x23 (1 bytes) // cell: buffer: {73 79 7a 30 3a} (length 0x5) // volname: buffer: {73 79 7a 30} (length 0x4) // suffix: buffer: {} (length 0x0) // z: const = 0x0 (1 bytes) // } // } // } // dst: ptr[in, buffer] { // buffer: {2e 2f 66 69 6c 65 30 00} (length 0x8) // } // type: ptr[in, buffer] { // buffer: {61 66 73 00} (length 0x4) // } // flags: mount_flags = 0x0 (8 bytes) // opts: nil // ] *(uint8_t*)0x20000d00 = 0x23; memcpy((void*)0x20000d01, "syz0:", 5); memcpy((void*)0x20000d06, "syz0", 4); *(uint8_t*)0x20000d0a = 0; memcpy((void*)0x20000b00, "./file0\000", 8); memcpy((void*)0x20000c00, "afs\000", 4); syscall(__NR_mount, /*src=*/0x20000d00ul, /*dst=*/0x20000b00ul, /*type=*/0x20000c00ul, /*flags=*/0ul, /*opts=*/0ul); } 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 < 5; procid++) { if (fork() == 0) { loop(); } } sleep(1000000); return 0; }