// https://syzkaller.appspot.com/bug?id=4f0ccff293413eb0cf0a128ffe289b40727de986 // 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 #include #include #include static __thread int skip_segv; static __thread jmp_buf segv_env; static void segv_handler(int sig, siginfo_t* info, void* ctx) { 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); } #define BITMASK(bf_off, bf_len) (((1ull << (bf_len)) - 1) << (bf_off)) #define STORE_BY_BITMASK(type, htobe, addr, val, bf_off, bf_len) \ *(type*)(addr) = \ htobe((htobe(*(type*)(addr)) & ~BITMASK((bf_off), (bf_len))) | \ (((type)(val) << (bf_off)) & BITMASK((bf_off), (bf_len)))) 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 SQ_HEAD_OFFSET 0 #define SQ_TAIL_OFFSET 64 #define SQ_RING_MASK_OFFSET 256 #define SQ_RING_ENTRIES_OFFSET 264 #define SQ_FLAGS_OFFSET 276 #define SQ_DROPPED_OFFSET 272 #define CQ_HEAD_OFFSET 128 #define CQ_TAIL_OFFSET 192 #define CQ_RING_MASK_OFFSET 260 #define CQ_RING_ENTRIES_OFFSET 268 #define CQ_RING_OVERFLOW_OFFSET 284 #define CQ_FLAGS_OFFSET 280 #define CQ_CQES_OFFSET 320 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 resv2; }; struct io_cqring_offsets { uint32_t head; uint32_t tail; uint32_t ring_mask; uint32_t ring_entries; uint32_t overflow; uint32_t cqes; uint64_t resv[2]; }; 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; }; #define IORING_OFF_SQ_RING 0 #define IORING_OFF_SQES 0x10000000ULL #define sys_io_uring_setup 425 static long syz_io_uring_setup(volatile long a0, volatile long a1, volatile long a2, volatile long a3, volatile long a4, volatile long a5) { uint32_t entries = (uint32_t)a0; struct io_uring_params* setup_params = (struct io_uring_params*)a1; void* vma1 = (void*)a2; void* vma2 = (void*)a3; void** ring_ptr_out = (void**)a4; void** sqes_ptr_out = (void**)a5; uint32_t fd_io_uring = syscall(sys_io_uring_setup, entries, setup_params); uint32_t sq_ring_sz = setup_params->sq_off.array + setup_params->sq_entries * sizeof(uint32_t); uint32_t cq_ring_sz = setup_params->cq_off.cqes + setup_params->cq_entries * SIZEOF_IO_URING_CQE; uint32_t ring_sz = sq_ring_sz > cq_ring_sz ? sq_ring_sz : cq_ring_sz; *ring_ptr_out = mmap(vma1, ring_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE | MAP_FIXED, fd_io_uring, IORING_OFF_SQ_RING); uint32_t sqes_sz = setup_params->sq_entries * SIZEOF_IO_URING_SQE; *sqes_ptr_out = mmap(vma2, sqes_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE | MAP_FIXED, fd_io_uring, IORING_OFF_SQES); return fd_io_uring; } static long syz_io_uring_submit(volatile long a0, volatile long a1, volatile long a2, volatile long a3) { char* ring_ptr = (char*)a0; char* sqes_ptr = (char*)a1; char* sqe = (char*)a2; uint32_t sqes_index = (uint32_t)a3; uint32_t sq_ring_entries = *(uint32_t*)(ring_ptr + SQ_RING_ENTRIES_OFFSET); uint32_t cq_ring_entries = *(uint32_t*)(ring_ptr + CQ_RING_ENTRIES_OFFSET); uint32_t sq_array_off = (CQ_CQES_OFFSET + cq_ring_entries * SIZEOF_IO_URING_CQE + 63) & ~63; if (sq_ring_entries) sqes_index %= sq_ring_entries; char* sqe_dest = sqes_ptr + sqes_index * SIZEOF_IO_URING_SQE; memcpy(sqe_dest, sqe, SIZEOF_IO_URING_SQE); uint32_t sq_ring_mask = *(uint32_t*)(ring_ptr + SQ_RING_MASK_OFFSET); uint32_t* sq_tail_ptr = (uint32_t*)(ring_ptr + SQ_TAIL_OFFSET); uint32_t sq_tail = *sq_tail_ptr & sq_ring_mask; uint32_t sq_tail_next = *sq_tail_ptr + 1; uint32_t* sq_array = (uint32_t*)(ring_ptr + sq_array_off); *(sq_array + sq_tail) = sqes_index; __atomic_store_n(sq_tail_ptr, sq_tail_next, __ATOMIC_RELEASE); return 0; } #define MAX_FDS 30 static void setup_common() { if (mount(0, "/sys/fs/fuse/connections", "fusectl", 0, 0)) { } } static void loop(); static void sandbox_common() { prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0); setsid(); struct rlimit rlim; rlim.rlim_cur = rlim.rlim_max = (200 << 20); setrlimit(RLIMIT_AS, &rlim); rlim.rlim_cur = rlim.rlim_max = 32 << 20; setrlimit(RLIMIT_MEMLOCK, &rlim); rlim.rlim_cur = rlim.rlim_max = 136 << 20; setrlimit(RLIMIT_FSIZE, &rlim); rlim.rlim_cur = rlim.rlim_max = 1 << 20; setrlimit(RLIMIT_STACK, &rlim); rlim.rlim_cur = rlim.rlim_max = 0; setrlimit(RLIMIT_CORE, &rlim); rlim.rlim_cur = rlim.rlim_max = 256; setrlimit(RLIMIT_NOFILE, &rlim); if (unshare(CLONE_NEWNS)) { } if (mount(NULL, "/", NULL, MS_REC | MS_PRIVATE, NULL)) { } if (unshare(CLONE_NEWIPC)) { } if (unshare(0x02000000)) { } if (unshare(CLONE_NEWUTS)) { } if (unshare(CLONE_SYSVSEM)) { } typedef struct { const char* name; const char* value; } sysctl_t; static const sysctl_t sysctls[] = { {"/proc/sys/kernel/shmmax", "16777216"}, {"/proc/sys/kernel/shmall", "536870912"}, {"/proc/sys/kernel/shmmni", "1024"}, {"/proc/sys/kernel/msgmax", "8192"}, {"/proc/sys/kernel/msgmni", "1024"}, {"/proc/sys/kernel/msgmnb", "1024"}, {"/proc/sys/kernel/sem", "1024 1048576 500 1024"}, }; unsigned i; for (i = 0; i < sizeof(sysctls) / sizeof(sysctls[0]); i++) write_file(sysctls[i].name, sysctls[i].value); } static int wait_for_loop(int pid) { if (pid < 0) exit(1); int status = 0; while (waitpid(-1, &status, __WALL) != pid) { } return WEXITSTATUS(status); } static void drop_caps(void) { struct __user_cap_header_struct cap_hdr = {}; struct __user_cap_data_struct cap_data[2] = {}; cap_hdr.version = _LINUX_CAPABILITY_VERSION_3; cap_hdr.pid = getpid(); if (syscall(SYS_capget, &cap_hdr, &cap_data)) exit(1); const int drop = (1 << CAP_SYS_PTRACE) | (1 << CAP_SYS_NICE); cap_data[0].effective &= ~drop; cap_data[0].permitted &= ~drop; cap_data[0].inheritable &= ~drop; if (syscall(SYS_capset, &cap_hdr, &cap_data)) exit(1); } static int do_sandbox_none(void) { if (unshare(CLONE_NEWPID)) { } int pid = fork(); if (pid != 0) return wait_for_loop(pid); setup_common(); sandbox_common(); drop_caps(); if (unshare(CLONE_NEWNET)) { } loop(); exit(1); } #define FS_IOC_SETFLAGS _IOW('f', 2, long) static void remove_dir(const char* dir) { int iter = 0; DIR* dp = 0; retry: while (umount2(dir, MNT_DETACH) == 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, MNT_DETACH) == 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, MNT_DETACH)) 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, MNT_DETACH)) 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"); } static void close_fds() { for (int fd = 3; fd < MAX_FDS; fd++) close(fd); } 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(); close_fds(); exit(0); } int status = 0; uint64_t start = current_time_ms(); for (;;) { if (waitpid(-1, &status, WNOHANG | WAIT_FLAGS) == pid) break; sleep_ms(1); if (current_time_ms() - start < 5000) continue; kill_and_wait(pid, &status); break; } remove_dir(cwdbuf); } } #ifndef __NR_io_uring_enter #define __NR_io_uring_enter 426 #endif uint64_t r[3] = {0xffffffffffffffff, 0x0, 0x0}; void execute_one(void) { intptr_t res = 0; NONFAILING(*(uint32_t*)0x2001d000 = 1); NONFAILING(*(uint32_t*)0x2001d004 = 0x80); NONFAILING(*(uint8_t*)0x2001d008 = 0); NONFAILING(*(uint8_t*)0x2001d009 = 0); NONFAILING(*(uint8_t*)0x2001d00a = 0); NONFAILING(*(uint8_t*)0x2001d00b = 0); NONFAILING(*(uint32_t*)0x2001d00c = 0); NONFAILING(*(uint64_t*)0x2001d010 = 4); NONFAILING(*(uint64_t*)0x2001d018 = 0); NONFAILING(*(uint64_t*)0x2001d020 = 0); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 0, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 1, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 2, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 3, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 4, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 5, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 6, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 7, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 8, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 9, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 10, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 11, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 12, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 13, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 14, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 15, 2)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 17, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 18, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 19, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 20, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 21, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 22, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 23, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 24, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 25, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 26, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 27, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 28, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 29, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 30, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 31, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 32, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 33, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 34, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 35, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 36, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 37, 1)); NONFAILING(STORE_BY_BITMASK(uint64_t, , 0x2001d028, 0, 38, 26)); NONFAILING(*(uint32_t*)0x2001d030 = 0); NONFAILING(*(uint32_t*)0x2001d034 = 0); NONFAILING(*(uint64_t*)0x2001d038 = 0); NONFAILING(*(uint64_t*)0x2001d040 = 0); NONFAILING(*(uint64_t*)0x2001d048 = 0); NONFAILING(*(uint64_t*)0x2001d050 = 0); NONFAILING(*(uint32_t*)0x2001d058 = 0); NONFAILING(*(uint32_t*)0x2001d05c = 0); NONFAILING(*(uint64_t*)0x2001d060 = 0); NONFAILING(*(uint32_t*)0x2001d068 = 0); NONFAILING(*(uint16_t*)0x2001d06c = 0); NONFAILING(*(uint16_t*)0x2001d06e = 0); NONFAILING(*(uint32_t*)0x2001d070 = 0); NONFAILING(*(uint32_t*)0x2001d074 = 0); NONFAILING(*(uint64_t*)0x2001d078 = 0); syscall(__NR_perf_event_open, 0x2001d000ul, 0, 0ul, -1, 0ul); NONFAILING(*(uint32_t*)0x20000244 = 0); NONFAILING(*(uint32_t*)0x20000248 = 0); NONFAILING(*(uint32_t*)0x2000024c = 0); NONFAILING(*(uint32_t*)0x20000250 = 0); NONFAILING(*(uint32_t*)0x20000258 = 0); NONFAILING(memset((void*)0x2000025c, 0, 12)); res = -1; NONFAILING(res = syz_io_uring_setup(0x2de1, 0x20000240, 0x20002000, 0x20ffd000, 0x20000100, 0x20000140)); if (res != -1) { r[0] = res; NONFAILING(r[1] = *(uint64_t*)0x20000100); NONFAILING(r[2] = *(uint64_t*)0x20000140); } NONFAILING(*(uint8_t*)0x200001c0 = 1); NONFAILING(*(uint8_t*)0x200001c1 = 2); NONFAILING(*(uint16_t*)0x200001c2 = 0); NONFAILING(*(uint32_t*)0x200001c4 = 4); NONFAILING(*(uint64_t*)0x200001c8 = 0); NONFAILING(*(uint64_t*)0x200001d0 = 0); NONFAILING(*(uint32_t*)0x200001d8 = 0); NONFAILING(*(uint32_t*)0x200001dc = 0); NONFAILING(*(uint64_t*)0x200001e0 = 0); NONFAILING(*(uint16_t*)0x200001e8 = 0); NONFAILING(*(uint16_t*)0x200001ea = 0); NONFAILING(memset((void*)0x200001ec, 0, 20)); NONFAILING(syz_io_uring_submit(r[1], r[2], 0x200001c0, 0)); syscall(__NR_io_uring_enter, r[0], 0x302, 0x1100, 0ul, 0ul, 1ul); } int main(void) { syscall(__NR_mmap, 0x1ffff000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x32ul, -1, 0ul); syscall(__NR_mmap, 0x21000000ul, 0x1000ul, 0ul, 0x32ul, -1, 0ul); install_segv_handler(); use_temporary_dir(); do_sandbox_none(); return 0; }