// https://syzkaller.appspot.com/bug?id=36017a84a0af6b7b7a70517870d4416c63bbc01d // 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 #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 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; } #define SIZEOF_IO_URING_SQE 64 #define SIZEOF_IO_URING_CQE 16 #define IORING_SETUP_SQE128 (1U << 10) #define IORING_SETUP_CQE32 (1U << 11) struct io_sqring_offsets { uint32_t head; uint32_t tail; uint32_t ring_mask; uint32_t ring_entries; uint32_t flags; uint32_t dropped; uint32_t array; uint32_t resv1; uint64_t user_addr; }; struct io_cqring_offsets { uint32_t head; uint32_t tail; uint32_t ring_mask; uint32_t ring_entries; uint32_t overflow; uint32_t cqes; uint32_t flags; uint32_t resv1; uint64_t user_addr; }; struct io_uring_params { uint32_t sq_entries; uint32_t cq_entries; uint32_t flags; uint32_t sq_thread_cpu; uint32_t sq_thread_idle; uint32_t features; uint32_t resv[4]; struct io_sqring_offsets sq_off; struct io_cqring_offsets cq_off; }; static long io_uring_sqe_size(struct io_uring_params* params) { return SIZEOF_IO_URING_SQE << !!(params->flags & IORING_SETUP_SQE128); } static long syz_io_uring_submit(volatile long a0, volatile long a1, volatile long a2, volatile long a3) { struct io_uring_params* params = (struct io_uring_params*)a0; char* ring_ptr = (char*)a1; char* sqes_ptr = (char*)a2; char* sqe = (char*)a3; uint32_t sq_ring_mask = *(uint32_t*)(ring_ptr + params->sq_off.ring_mask); uint32_t* sq_tail_ptr = (uint32_t*)(ring_ptr + params->sq_off.tail); uint32_t sq_tail = *sq_tail_ptr & sq_ring_mask; uint32_t sqe_size = io_uring_sqe_size(params); char* sqe_dest = sqes_ptr + sq_tail * sqe_size; memcpy(sqe_dest, sqe, sqe_size); uint32_t sq_tail_next = *sq_tail_ptr + 1; __atomic_store_n(sq_tail_ptr, sq_tail_next, __ATOMIC_RELEASE); return 0; } #define UBLK_F_USER_COPY (1UL << 7) #define UBLK_IO_RES_OK 0 #define UBLK_IO_RES_NEED_GET_DATA 1 #define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21 #define UBLK_IO_NEED_GET_DATA 0x22 #define UBLK_U_IO_COMMIT_AND_FETCH_REQ \ _IOWR('u', UBLK_IO_COMMIT_AND_FETCH_REQ, struct ublksrv_io_cmd) #define UBLK_U_IO_NEED_GET_DATA \ _IOWR('u', UBLK_IO_NEED_GET_DATA, struct ublksrv_io_cmd) struct ublksrv_ctrl_cmd { __u32 dev_id; __u16 queue_id; __u16 len; __u64 addr; __u64 data[1]; __u16 dev_path_len; __u16 pad; __u32 reserved; }; struct ublksrv_ctrl_dev_info { __u16 nr_hw_queues; __u16 queue_depth; __u16 state; __u16 pad0; __u32 max_io_buf_bytes; __u32 dev_id; __s32 ublksrv_pid; __u32 pad1; __u64 flags; __u64 ublksrv_flags; __u32 owner_uid; __u32 owner_gid; __u64 reserved1; __u64 reserved2; }; struct ublksrv_io_desc { __u32 op_flags; union { __u32 nr_sectors; __u32 nr_zones; }; __u64 start_sector; __u64 addr; }; struct ublksrv_io_cmd { __u16 q_id; __u16 tag; __s32 result; union { __u64 addr; __u64 zone_append_lba; }; }; struct io_uring_sqe { __u8 opcode; __u8 flags; __u16 ioprio; __s32 fd; union { __u64 off; __u64 addr2; struct { __u32 cmd_op; __u32 __pad1; }; }; union { __u64 addr; __u64 splice_off_in; struct { __u32 level; __u32 optname; }; }; __u32 len; union { __kernel_rwf_t rw_flags; __u32 fsync_flags; __u16 poll_events; __u32 poll32_events; __u32 sync_range_flags; __u32 msg_flags; __u32 timeout_flags; __u32 accept_flags; __u32 cancel_flags; __u32 open_flags; __u32 statx_flags; __u32 fadvise_advice; __u32 splice_flags; __u32 rename_flags; __u32 unlink_flags; __u32 hardlink_flags; __u32 xattr_flags; __u32 msg_ring_flags; __u32 uring_cmd_flags; __u32 waitid_flags; __u32 futex_flags; __u32 install_fd_flags; __u32 nop_flags; __u32 pipe_flags; }; __u64 user_data; union { __u16 buf_index; __u16 buf_group; } __attribute__((packed)); __u16 personality; union { __s32 splice_fd_in; __u32 file_index; __u32 zcrx_ifq_idx; __u32 optlen; struct { __u16 addr_len; __u16 __pad3[1]; }; }; union { struct { __u64 addr3; __u64 __pad2[1]; }; struct { __u64 attr_ptr; __u64 attr_type_mask; }; __u64 optval; __u8 cmd[0]; }; }; static long syz_ublk_add_dev(volatile long a0, volatile long a1, volatile long a2, volatile long a3, volatile long a4, volatile long a5) { __u32 ring_fd = (__u32)a0; struct io_uring_params* params = (struct io_uring_params*)a1; char* ring_ptr = (char*)a2; char* sqes_ptr = (char*)a3; struct io_uring_sqe* sqe = (struct io_uring_sqe*)a4; void** dev_info_ptr_out = (void**)a5; struct ublksrv_ctrl_cmd* cmd = (struct ublksrv_ctrl_cmd*)(sqe->cmd); struct ublksrv_ctrl_dev_info* dev_info = (struct ublksrv_ctrl_dev_info*)(unsigned long)(cmd->addr); dev_info->flags |= UBLK_F_USER_COPY; int ret = syz_io_uring_submit((long)params, (long)ring_ptr, (long)sqes_ptr, (long)sqe); if (ret < 0) return (long)ret; syscall(__NR_io_uring_enter, ring_fd, 1, 1, 1, NULL, _NSIG / 8); *dev_info_ptr_out = (void*)dev_info; return dev_info->dev_id; } 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 setup_sysctl() { int cad_pid = fork(); if (cad_pid < 0) exit(1); if (cad_pid == 0) { for (;;) sleep(100); } char tmppid[32]; snprintf(tmppid, sizeof(tmppid), "%d", cad_pid); struct { const char* name; const char* data; } files[] = { {"/sys/kernel/debug/x86/nmi_longest_ns", "10000000000"}, {"/proc/sys/kernel/hung_task_check_interval_secs", "20"}, {"/proc/sys/net/core/bpf_jit_kallsyms", "1"}, {"/proc/sys/net/core/bpf_jit_harden", "0"}, {"/proc/sys/kernel/kptr_restrict", "0"}, {"/proc/sys/kernel/softlockup_all_cpu_backtrace", "1"}, {"/proc/sys/fs/mount-max", "100"}, {"/proc/sys/vm/oom_dump_tasks", "0"}, {"/proc/sys/debug/exception-trace", "0"}, {"/proc/sys/kernel/printk", "7 4 1 3"}, {"/proc/sys/kernel/keys/gc_delay", "1"}, {"/proc/sys/vm/oom_kill_allocating_task", "1"}, {"/sys/kernel/debug/failslab/task-filter", "Y"}, {"/sys/kernel/debug/fail_page_alloc/task-filter", "Y"}, {"/sys/kernel/debug/fail_futex/task-filter", "Y"}, {"/sys/kernel/debug/fail_usercopy/task-filter", "Y"}, {"/sys/kernel/debug/fail_make_request/task-filter", "Y"}, {"/sys/kernel/debug/fail_io_timeout/task-filter", "Y"}, {"/sys/kernel/debug/fail_iommufd/task-filter", "Y"}, {"/proc/sys/kernel/ctrl-alt-del", "0"}, {"/proc/sys/kernel/cad_pid", tmppid}, }; for (size_t i = 0; i < sizeof(files) / sizeof(files[0]); i++) { if (!write_file(files[i].name, files[i].data)) { } } kill(cad_pid, SIGKILL); while (waitpid(cad_pid, NULL, 0) != cad_pid) ; } 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[2] = {0xffffffffffffffff, 0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } // syz_ublk_add_dev arguments: [ // fd_io_uring: fd_io_uring (resource) // ring_params_ptr: ring_params_ptr (resource) // ring_ptr: ring_ptr (resource) // sqes_ptr: sqes_ptr (resource) // sqe: nil // dev_info_ptr: nil // ] // returns ublk_dev_id NONFAILING(syz_ublk_add_dev(/*fd_io_uring=*/-1, /*ring_params_ptr=*/0, /*ring_ptr=*/0, /*sqes_ptr=*/0, /*sqe=*/0, /*dev_info_ptr=*/0)); // ioctl$SNDRV_CTL_IOCTL_ELEM_ADD arguments: [ // fd: fd_sndctrl (resource) // cmd: const = 0xc1105517 (4 bytes) // arg: nil // ] syscall(__NR_ioctl, /*fd=*/(intptr_t)-1, /*cmd=*/0xc1105517, /*arg=*/0ul); // openat$binder_debug arguments: [ // fd: const = 0xffffffffffffff9c (8 bytes) // file: nil // flags: const = 0x0 (4 bytes) // mode: const = 0x0 (2 bytes) // ] // returns fd syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0ul, /*flags=*/0, /*mode=*/0); // openat$binderfs arguments: [ // fd: const = 0xffffffffffffff9c (8 bytes) // file: nil // flags: binder_open_flags = 0x2 (4 bytes) // mode: const = 0x0 (2 bytes) // ] // returns fd_binder syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0ul, /*flags=O_RDWR*/ 2, /*mode=*/0); // mkdirat arguments: [ // fd: fd_dir (resource) // path: ptr[in, buffer] { // buffer: {2e 2f 67 61 64 67 65 74 00} (length 0x9) // } // mode: open_mode = 0x1ff (8 bytes) // ] NONFAILING(memcpy((void*)0x200000000040, "./gadget\000", 9)); syscall( __NR_mkdirat, /*fd=*/0xffffff9c, /*path=*/0x200000000040ul, /*mode=S_IXOTH|S_IWOTH|S_IROTH|S_IXGRP|S_IWGRP|S_IRGRP|S_IXUSR|S_IWUSR|0x100*/ 0x1fful); // close arguments: [ // fd: fd (resource) // ] syscall(__NR_close, /*fd=*/3); // setsockopt$sock_int arguments: [ // fd: sock (resource) // level: const = 0x1 (4 bytes) // optname: sockopt_opt_sock_int = 0x20 (4 bytes) // optval: nil // optlen: len = 0x0 (8 bytes) // ] syscall(__NR_setsockopt, /*fd=*/(intptr_t)-1, /*level=*/1, /*optname=SO_SNDBUFFORCE*/ 0x20, /*optval=*/0ul, /*optlen=*/0ul); // mount arguments: [ // src: nil // dst: ptr[in, buffer] { // buffer: {2e 2f 67 61 64 67 65 74 00} (length 0x9) // } // type: ptr[in, buffer] { // buffer: {67 61 64 67 65 74 66 73 00} (length 0x9) // } // flags: mount_flags = 0x0 (8 bytes) // data: nil // ] NONFAILING(memcpy((void*)0x200000000100, "./gadget\000", 9)); NONFAILING(memcpy((void*)0x200000000200, "gadgetfs\000", 9)); syscall(__NR_mount, /*src=*/0ul, /*dst=*/0x200000000100ul, /*type=*/0x200000000200ul, /*flags=*/0ul, /*data=*/0ul); // openat arguments: [ // fd: fd_dir (resource) // file: ptr[in, buffer] { // buffer: {2e 2f 67 61 64 67 65 74 2f 64 75 6d 6d 79 5f 75 64 63 00} // (length 0x13) // } // flags: open_flags = 0x802 (4 bytes) // mode: open_mode = 0x0 (2 bytes) // ] // returns fd NONFAILING(memcpy((void*)0x200000000300, "./gadget/dummy_udc\000", 19)); res = syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x200000000300ul, /*flags=O_NONBLOCK|O_RDWR*/ 0x802, /*mode=*/0); if (res != -1) r[0] = res; // write arguments: [ // fd: fd (resource) // buf: ptr[in, buffer] { // buffer: {00 00 00 00 09 02 09 00 01 01 00 80 32 12 01 00 02 00 00 00 // 40 25 05 a0 a4 00 01 00 00 00 01} (length 0x1f) // } // count: len = 0x1f (8 bytes) // ] NONFAILING( memcpy((void*)0x200000000400, "\x00\x00\x00\x00\x09\x02\x09\x00\x01\x01\x00\x80\x32\x12\x01\x00" "\x02\x00\x00\x00\x40\x25\x05\xa0\xa4\x00\x01\x00\x00\x00\x01", 31)); syscall(__NR_write, /*fd=*/r[0], /*buf=*/0x200000000400ul, /*count=*/0x1ful); // openat arguments: [ // fd: fd_dir (resource) // file: ptr[in, buffer] { // buffer: {2e 2f 67 61 64 67 65 74 2f 65 70 31 69 6e 2d 62 75 6c 6b 00} // (length 0x14) // } // flags: open_flags = 0x2 (4 bytes) // mode: open_mode = 0x0 (2 bytes) // ] // returns fd NONFAILING(memcpy((void*)0x200000000600, "./gadget/ep1in-bulk\000", 20)); res = syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x200000000600ul, /*flags=O_RDWR*/ 2, /*mode=*/0); if (res != -1) r[1] = res; // write arguments: [ // fd: fd (resource) // buf: nil // count: len = 0xb00 (8 bytes) // ] syscall(__NR_write, /*fd=*/r[1], /*buf=*/0ul, /*count=*/0xb00ul); } 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); setup_sysctl(); const char* reason; (void)reason; install_segv_handler(); for (procid = 0; procid < 5; procid++) { if (fork() == 0) { loop(); } } sleep(1000000); return 0; }