// https://syzkaller.appspot.com/bug?id=886a081cde9d0bf08c2ad5040ba0e83ef53b4eb3 // autogenerated by syzkaller (https://github.com/google/syzkaller) #define _GNU_SOURCE #include #include #include #include #include #include #include #include #include #include #include #include #ifndef __NR_io_uring_setup #define __NR_io_uring_setup 425 #endif 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; \ }) #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 io_uring_cqe_size(struct io_uring_params* params) { return SIZEOF_IO_URING_CQE << !!(params->flags & IORING_SETUP_CQE32); } #define IORING_OFF_SQ_RING 0ULL #define IORING_OFF_SQES 0x10000000ULL static long syz_io_uring_setup(volatile long a0, volatile long a1, volatile long a2, volatile long a3, volatile long a4) { uint32_t entries = (uint32_t)a0; struct io_uring_params* setup_params = (struct io_uring_params*)a1; void** ring_params_ptr_out = (void**)a2; void** ring_ptr_out = (void**)a3; void** sqes_ptr_out = (void**)a4; uint32_t fd_io_uring = syscall(__NR_io_uring_setup, entries, setup_params); *ring_params_ptr_out = (void*)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 * io_uring_cqe_size(setup_params); uint32_t ring_sz = sq_ring_sz > cq_ring_sz ? sq_ring_sz : cq_ring_sz; *ring_ptr_out = mmap(0, ring_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd_io_uring, IORING_OFF_SQ_RING); uint32_t sqes_sz = setup_params->sq_entries * io_uring_sqe_size(setup_params); *sqes_ptr_out = mmap(0, sqes_sz, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_POPULATE, fd_io_uring, IORING_OFF_SQES); uint32_t* array = (uint32_t*)((uintptr_t)*ring_ptr_out + setup_params->sq_off.array); for (uint32_t index = 0; index < setup_params->sq_entries; index++) array[index] = index; return fd_io_uring; } 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; } uint64_t r[3] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; 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; install_segv_handler(); 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 73 79 73 00} (length 0x6) // } // mode: open_mode = 0x1ff (8 bytes) // ] NONFAILING(memcpy((void*)0x200000000000, "./sys\000", 6)); syscall( __NR_mkdirat, /*fd=*/0xffffff9c, /*path=*/0x200000000000ul, /*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 73 79 73 00} (length 0x6) // } // type: ptr[in, buffer] { // buffer: {73 79 73 66 73 00} (length 0x6) // } // flags: mount_flags = 0x0 (8 bytes) // data: nil // ] NONFAILING(memcpy((void*)0x200000000000, "./sys\000", 6)); NONFAILING(memcpy((void*)0x200000000040, "sysfs\000", 6)); syscall(__NR_mount, /*src=*/0ul, /*dst=*/0x200000000000ul, /*type=*/0x200000000040ul, /*flags=*/0ul, /*data=*/0ul); // openat arguments: [ // fd: fd_dir (resource) // file: ptr[in, buffer] { // buffer: {2e 2f 73 79 73 2f 62 75 73 2f 70 63 69 2f 64 65 76 69 63 65 // 73 2f 30 30 30 30 3a 30 30 3a 30 32 2e 30 2f 64 72 69 76 65 72 2f 75 // 6e 62 69 6e 64 00} (length 0x31) // } // flags: open_flags = 0x1 (4 bytes) // mode: open_mode = 0x0 (2 bytes) // ] // returns fd NONFAILING(memcpy((void*)0x200000000080, "./sys/bus/pci/devices/0000:00:02.0/driver/unbind\000", 49)); res = syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x200000000080ul, /*flags=O_WRONLY*/ 1, /*mode=*/0); if (res != -1) r[0] = res; // write arguments: [ // fd: fd (resource) // buf: ptr[in, buffer] { // buffer: {30 30 30 30 3a 30 30 3a 30 32 2e 30 00} (length 0xd) // } // count: len = 0xc (8 bytes) // ] NONFAILING(memcpy((void*)0x2000000000c0, "0000:00:02.0\000", 13)); syscall(__NR_write, /*fd=*/r[0], /*buf=*/0x2000000000c0ul, /*count=*/0xcul); // mmap arguments: [ // addr: VMA[0x1000] // len: len = 0x1000 (4 bytes) // prot: mmap_prot = 0x3 (8 bytes) // flags: mmap_flags = 0x11 (8 bytes) // fd: fd (resource) // offset: intptr = 0x0 (8 bytes) // ] syscall(__NR_mmap, /*addr=*/0x200000001000ul, /*len=*/0x1000, /*prot=PROT_WRITE|PROT_READ*/ 3ul, /*flags=MAP_FIXED|MAP_SHARED*/ 0x11ul, /*fd=*/(intptr_t)-1, /*offset=*/0ul); // openat arguments: [ // fd: fd_dir (resource) // file: nil // flags: open_flags = 0x2 (4 bytes) // mode: open_mode = 0x0 (2 bytes) // ] // returns fd syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0ul, /*flags=O_RDWR*/ 2, /*mode=*/0); // syz_io_uring_setup arguments: [ // entries: int32 = 0xf00 (4 bytes) // params: nil // ring_params_ptr: nil // ring_ptr: nil // sqes_ptr: nil // ] // returns fd_io_uring NONFAILING(syz_io_uring_setup(/*entries=*/0xf00, /*params=*/0, /*ring_params_ptr=*/0, /*ring_ptr=*/0, /*sqes_ptr=*/0)); // syz_io_uring_submit arguments: [ // ring_params_ptr: ring_params_ptr (resource) // ring_ptr: ring_ptr (resource) // sqes_ptr: sqes_ptr (resource) // sqe: nil // ] NONFAILING(syz_io_uring_submit(/*ring_params_ptr=*/0, /*ring_ptr=*/0, /*sqes_ptr=*/0, /*sqe=*/0)); // openat arguments: [ // fd: fd_dir (resource) // file: ptr[in, buffer] { // buffer: {2e 2f 73 79 73 2f 62 75 73 2f 70 63 69 2f 64 65 76 69 63 65 // 73 2f 30 30 30 30 3a 30 30 3a 30 32 2e 30 2f 64 72 69 76 65 72 5f 6f // 76 65 72 72 69 64 65 00} (length 0x33) // } // flags: open_flags = 0x1 (4 bytes) // mode: open_mode = 0x0 (2 bytes) // ] // returns fd NONFAILING(memcpy((void*)0x200000000200, "./sys/bus/pci/devices/0000:00:02.0/driver_override\000", 51)); res = syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x200000000200ul, /*flags=O_WRONLY*/ 1, /*mode=*/0); if (res != -1) r[1] = res; // write arguments: [ // fd: fd (resource) // buf: ptr[in, buffer] { // buffer: {65 31 30 30 00} (length 0x5) // } // count: len = 0x4 (8 bytes) // ] NONFAILING(memcpy((void*)0x200000000240, "e100\000", 5)); syscall(__NR_write, /*fd=*/r[1], /*buf=*/0x200000000240ul, /*count=*/4ul); // openat arguments: [ // fd: fd_dir (resource) // file: ptr[in, buffer] { // buffer: {2e 2f 73 79 73 2f 62 75 73 2f 70 63 69 2f 64 72 69 76 65 72 // 73 2f 65 31 30 30 2f 62 69 6e 64 00} (length 0x20) // } // flags: open_flags = 0x1 (4 bytes) // mode: open_mode = 0x0 (2 bytes) // ] // returns fd NONFAILING( memcpy((void*)0x200000000280, "./sys/bus/pci/drivers/e100/bind\000", 32)); res = syscall(__NR_openat, /*fd=*/0xffffff9c, /*file=*/0x200000000280ul, /*flags=O_WRONLY*/ 1, /*mode=*/0); if (res != -1) r[2] = res; // write arguments: [ // fd: fd (resource) // buf: ptr[in, buffer] { // buffer: {30 30 30 30 3a 30 30 3a 30 32 2e 30 00} (length 0xd) // } // count: len = 0xc (8 bytes) // ] NONFAILING(memcpy((void*)0x2000000002c0, "0000:00:02.0\000", 13)); syscall(__NR_write, /*fd=*/r[2], /*buf=*/0x2000000002c0ul, /*count=*/0xcul); return 0; }