// https://syzkaller.appspot.com/bug?id=e1a20486172174dc619b82460ab909d36fe83101 // 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 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; \ }) struct nlmsg { char* pos; int nesting; struct nlattr* nested[8]; char buf[4096]; }; static void netlink_init(struct nlmsg* nlmsg, int typ, int flags, const void* data, int size) { memset(nlmsg, 0, sizeof(*nlmsg)); struct nlmsghdr* hdr = (struct nlmsghdr*)nlmsg->buf; hdr->nlmsg_type = typ; hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | flags; memcpy(hdr + 1, data, size); nlmsg->pos = (char*)(hdr + 1) + NLMSG_ALIGN(size); } static void netlink_attr(struct nlmsg* nlmsg, int typ, const void* data, int size) { struct nlattr* attr = (struct nlattr*)nlmsg->pos; attr->nla_len = sizeof(*attr) + size; attr->nla_type = typ; if (size > 0) memcpy(attr + 1, data, size); nlmsg->pos += NLMSG_ALIGN(attr->nla_len); } static int netlink_send_ext(struct nlmsg* nlmsg, int sock, uint16_t reply_type, int* reply_len, bool dofail) { if (nlmsg->pos > nlmsg->buf + sizeof(nlmsg->buf) || nlmsg->nesting) exit(1); struct nlmsghdr* hdr = (struct nlmsghdr*)nlmsg->buf; hdr->nlmsg_len = nlmsg->pos - nlmsg->buf; struct sockaddr_nl addr; memset(&addr, 0, sizeof(addr)); addr.nl_family = AF_NETLINK; ssize_t n = sendto(sock, nlmsg->buf, hdr->nlmsg_len, 0, (struct sockaddr*)&addr, sizeof(addr)); if (n != (ssize_t)hdr->nlmsg_len) { if (dofail) exit(1); return -1; } n = recv(sock, nlmsg->buf, sizeof(nlmsg->buf), 0); if (reply_len) *reply_len = 0; if (n < 0) { if (dofail) exit(1); return -1; } if (n < (ssize_t)sizeof(struct nlmsghdr)) { errno = EINVAL; if (dofail) exit(1); return -1; } if (hdr->nlmsg_type == NLMSG_DONE) return 0; if (reply_len && hdr->nlmsg_type == reply_type) { *reply_len = n; return 0; } if (n < (ssize_t)(sizeof(struct nlmsghdr) + sizeof(struct nlmsgerr))) { errno = EINVAL; if (dofail) exit(1); return -1; } if (hdr->nlmsg_type != NLMSG_ERROR) { errno = EINVAL; if (dofail) exit(1); return -1; } errno = -((struct nlmsgerr*)(hdr + 1))->error; return -errno; } static int netlink_query_family_id(struct nlmsg* nlmsg, int sock, const char* family_name, bool dofail) { struct genlmsghdr genlhdr; memset(&genlhdr, 0, sizeof(genlhdr)); genlhdr.cmd = CTRL_CMD_GETFAMILY; netlink_init(nlmsg, GENL_ID_CTRL, 0, &genlhdr, sizeof(genlhdr)); netlink_attr(nlmsg, CTRL_ATTR_FAMILY_NAME, family_name, strnlen(family_name, GENL_NAMSIZ - 1) + 1); int n = 0; int err = netlink_send_ext(nlmsg, sock, GENL_ID_CTRL, &n, dofail); if (err < 0) { return -1; } uint16_t id = 0; struct nlattr* attr = (struct nlattr*)(nlmsg->buf + NLMSG_HDRLEN + NLMSG_ALIGN(sizeof(genlhdr))); for (; (char*)attr < nlmsg->buf + n; attr = (struct nlattr*)((char*)attr + NLMSG_ALIGN(attr->nla_len))) { if (attr->nla_type == CTRL_ATTR_FAMILY_ID) { id = *(uint16_t*)(attr + 1); break; } } if (!id) { errno = EINVAL; return -1; } recv(sock, nlmsg->buf, sizeof(nlmsg->buf), 0); return id; } static long syz_genetlink_get_family_id(volatile long name, volatile long sock_arg) { int fd = sock_arg; if (fd < 0) { fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC); if (fd == -1) { return -1; } } struct nlmsg nlmsg_tmp; int ret = netlink_query_family_id(&nlmsg_tmp, fd, (char*)name, false); if ((int)sock_arg < 0) close(fd); if (ret < 0) { return -1; } return ret; } uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; 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(); intptr_t res = 0; if (write(1, "executing program\n", sizeof("executing program\n") - 1)) { } res = syscall(__NR_socket, /*domain=*/0x10ul, /*type=*/3ul, /*proto=*/0x10); if (res != -1) r[0] = res; NONFAILING(syz_genetlink_get_family_id(/*name=*/0, /*fd=*/-1)); syscall(__NR_sendmsg, /*fd=*/r[0], /*msg=*/0ul, /*f=*/0ul); NONFAILING(memcpy((void*)0x200000000040, "/dev/comedi0\000", 13)); res = syscall(__NR_openat, /*fd=*/0xffffffffffffff9cul, /*file=*/0x200000000040ul, /*flags=O_NONBLOCK*/ 0x800, /*mode=*/0); if (res != -1) r[1] = res; NONFAILING(memcpy( (void*)0x200000000080, "das16m1\000\000\000\000\000\000\000\000\000\000\000\000\000", 20)); NONFAILING(*(uint32_t*)0x200000000094 = 0x2003); NONFAILING(*(uint32_t*)0x200000000098 = 0x4000003); NONFAILING(*(uint32_t*)0x20000000009c = 0); NONFAILING(*(uint32_t*)0x2000000000a0 = 0x400); NONFAILING(*(uint32_t*)0x2000000000a4 = 0x3a0b); NONFAILING(*(uint32_t*)0x2000000000a8 = 0x388); NONFAILING(*(uint32_t*)0x2000000000ac = 0x871); NONFAILING(*(uint32_t*)0x2000000000b0 = 6); NONFAILING(*(uint32_t*)0x2000000000b4 = 0x7fffffff); NONFAILING(*(uint32_t*)0x2000000000b8 = 0x4800); NONFAILING(*(uint32_t*)0x2000000000bc = 0x80000001); NONFAILING(*(uint32_t*)0x2000000000c0 = 6); NONFAILING(*(uint32_t*)0x2000000000c4 = 9); NONFAILING(*(uint32_t*)0x2000000000c8 = 0); NONFAILING(*(uint32_t*)0x2000000000cc = 4); NONFAILING(*(uint32_t*)0x2000000000d0 = 0); NONFAILING(*(uint32_t*)0x2000000000d4 = 0xe); NONFAILING(*(uint32_t*)0x2000000000d8 = 0); NONFAILING(*(uint32_t*)0x2000000000dc = 2); NONFAILING(*(uint32_t*)0x2000000000e0 = 2); NONFAILING(*(uint32_t*)0x2000000000e4 = 7); NONFAILING(*(uint32_t*)0x2000000000e8 = 0xffff1a8f); NONFAILING(*(uint32_t*)0x2000000000ec = 0xe9); NONFAILING(*(uint32_t*)0x2000000000f0 = 9); NONFAILING(*(uint32_t*)0x2000000000f4 = 0xb); NONFAILING(*(uint32_t*)0x2000000000f8 = 0x7fe); NONFAILING(*(uint32_t*)0x2000000000fc = 8); NONFAILING(*(uint32_t*)0x200000000100 = 0xb73c); NONFAILING(*(uint32_t*)0x200000000104 = 5); NONFAILING(*(uint32_t*)0x200000000108 = 1); NONFAILING(*(uint32_t*)0x20000000010c = 1); NONFAILING(*(uint32_t*)0x200000000110 = 0); syscall(__NR_ioctl, /*fd=*/r[1], /*cmd=*/0x40946400, /*arg=*/0x200000000080ul); return 0; }