// https://syzkaller.appspot.com/bug?id=a3878154d644f046cccf305a1f9ac723d25015bf // 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 __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; } static long syz_open_dev(volatile long a0, volatile long a1, volatile long a2) { if (a0 == 0xc || a0 == 0xb) { char buf[128]; sprintf(buf, "/dev/%s/%d:%d", a0 == 0xc ? "char" : "block", (uint8_t)a1, (uint8_t)a2); return open(buf, O_RDWR, 0); } else { unsigned long nb = a1; char buf[1024]; char* hash; strncpy(buf, (char*)a0, sizeof(buf) - 1); buf[sizeof(buf) - 1] = 0; while ((hash = strchr(buf, '#'))) { *hash = '0' + (char)(nb % 10); nb /= 10; } return open(buf, a2, 0); } } 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)) { } // syz_open_dev$dri arguments: [ // dev: ptr[in, buffer] { // buffer: {2f 64 65 76 2f 64 72 69 2f 63 61 72 64 23 00} (length 0xf) // } // id: intptr = 0x20 (8 bytes) // flags: open_flags = 0x0 (8 bytes) // ] // returns fd_dri NONFAILING(memcpy((void*)0x200000000040, "/dev/dri/card#\000", 15)); res = -1; NONFAILING( res = syz_open_dev(/*dev=*/0x200000000040, /*id=*/0x20, /*flags=*/0)); if (res != -1) r[0] = res; // ioctl$KVM_SET_USER_MEMORY_REGION arguments: [ // fd: fd_kvmvm (resource) // cmd: const = 0x4020ae46 (4 bytes) // arg: ptr[in, kvm_userspace_memory_region] { // kvm_userspace_memory_region { // slot: kvm_mem_slots = 0x0 (4 bytes) // flags: kvm_mem_region_flags = 0x0 (4 bytes) // paddr: kvm_guest_addrs = 0x0 (8 bytes) // size: len = 0x20002000 (8 bytes) // addr: VMA[0x2000] // } // } // ] NONFAILING(*(uint32_t*)0x200000000400 = 0); NONFAILING(*(uint32_t*)0x200000000404 = 0); NONFAILING(*(uint64_t*)0x200000000408 = 0); NONFAILING(*(uint64_t*)0x200000000410 = 0x20002000); NONFAILING(*(uint64_t*)0x200000000418 = 0x200000000000); syscall(__NR_ioctl, /*fd=*/(intptr_t)-1, /*cmd=*/0x4020ae46, /*arg=*/0x200000000400ul); // mprotect arguments: [ // addr: VMA[0x4000] // len: len = 0x4000 (8 bytes) // prot: mmap_prot = 0x1 (8 bytes) // ] syscall(__NR_mprotect, /*addr=*/0x200000000000ul, /*len=*/0x4000ul, /*prot=PROT_READ*/ 1ul); // ioctl$DRM_IOCTL_SYNCOBJ_WAIT arguments: [ // fd: fd_dri (resource) // cmd: const = 0xc02864c3 (4 bytes) // arg: ptr[inout, drm_syncobj_wait] { // drm_syncobj_wait { // handles: nil // timeout_nsec: int64 = 0x800000000000002 (8 bytes) // count_handles: len = 0x0 (4 bytes) // flags: drm_syncobj_wait_flags = 0xb (4 bytes) // first_signaled: int32 = 0x0 (4 bytes) // pad: const = 0x0 (4 bytes) // } // } // ] NONFAILING(*(uint64_t*)0x200000000400 = 0); NONFAILING(*(uint64_t*)0x200000000408 = 0x800000000000002); NONFAILING(*(uint32_t*)0x200000000410 = 0); NONFAILING(*(uint32_t*)0x200000000414 = 0xb); NONFAILING(*(uint32_t*)0x20000000041c = 0); syscall(__NR_ioctl, /*fd=*/r[0], /*cmd=*/0xc02864c3, /*arg=*/0x200000000400ul); } int main(void) { syscall(__NR_mmap, /*addr=*/0x1ffffffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); syscall(__NR_mmap, /*addr=*/0x200000000000ul, /*len=*/0x1000000ul, /*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=*/0x1000ul, /*prot=*/0ul, /*flags=MAP_FIXED|MAP_ANONYMOUS|MAP_PRIVATE*/ 0x32ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); const char* reason; (void)reason; install_segv_handler(); loop(); return 0; }