| // general protection fault in tun_queue_purge |
| // https://syzkaller.appspot.com/bug?id=5a0bd18cddb052aa9f5d9368f102d0a8dba1c194 |
| // status:fixed |
| // autogenerated by syzkaller (http://github.com/google/syzkaller) |
| |
| #define _GNU_SOURCE |
| #include <arpa/inet.h> |
| #include <endian.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <linux/if.h> |
| #include <linux/if_ether.h> |
| #include <linux/if_tun.h> |
| #include <linux/ip.h> |
| #include <linux/tcp.h> |
| #include <net/if_arp.h> |
| #include <stdarg.h> |
| #include <stdbool.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <sys/ioctl.h> |
| #include <sys/stat.h> |
| #include <sys/syscall.h> |
| #include <sys/uio.h> |
| #include <unistd.h> |
| |
| __attribute__((noreturn)) static void doexit(int status) |
| { |
| volatile unsigned i; |
| syscall(__NR_exit_group, status); |
| for (i = 0;; i++) { |
| } |
| } |
| #include <stdint.h> |
| #include <string.h> |
| |
| const int kFailStatus = 67; |
| const int kRetryStatus = 69; |
| |
| static void fail(const char* msg, ...) |
| { |
| int e = errno; |
| va_list args; |
| va_start(args, msg); |
| vfprintf(stderr, msg, args); |
| va_end(args); |
| fprintf(stderr, " (errno %d)\n", e); |
| doexit((e == ENOMEM || e == EAGAIN) ? kRetryStatus : kFailStatus); |
| } |
| |
| #define BITMASK_LEN(type, bf_len) (type)((1ull << (bf_len)) - 1) |
| |
| #define BITMASK_LEN_OFF(type, bf_off, bf_len) \ |
| (type)(BITMASK_LEN(type, (bf_len)) << (bf_off)) |
| |
| #define STORE_BY_BITMASK(type, addr, val, bf_off, bf_len) \ |
| if ((bf_off) == 0 && (bf_len) == 0) { \ |
| *(type*)(addr) = (type)(val); \ |
| } else { \ |
| type new_val = *(type*)(addr); \ |
| new_val &= ~BITMASK_LEN_OFF(type, (bf_off), (bf_len)); \ |
| new_val |= ((type)(val)&BITMASK_LEN(type, (bf_len))) << (bf_off); \ |
| *(type*)(addr) = new_val; \ |
| } |
| |
| struct csum_inet { |
| uint32_t acc; |
| }; |
| |
| static void csum_inet_init(struct csum_inet* csum) |
| { |
| csum->acc = 0; |
| } |
| |
| static void csum_inet_update(struct csum_inet* csum, const uint8_t* data, |
| size_t length) |
| { |
| if (length == 0) |
| return; |
| |
| size_t i; |
| for (i = 0; i < length - 1; i += 2) |
| csum->acc += *(uint16_t*)&data[i]; |
| |
| if (length & 1) |
| csum->acc += (uint16_t)data[length - 1]; |
| |
| while (csum->acc > 0xffff) |
| csum->acc = (csum->acc & 0xffff) + (csum->acc >> 16); |
| } |
| |
| static uint16_t csum_inet_digest(struct csum_inet* csum) |
| { |
| return ~csum->acc; |
| } |
| |
| static void vsnprintf_check(char* str, size_t size, const char* format, |
| va_list args) |
| { |
| int rv; |
| |
| rv = vsnprintf(str, size, format, args); |
| if (rv < 0) |
| fail("tun: snprintf failed"); |
| if ((size_t)rv >= size) |
| fail("tun: string '%s...' doesn't fit into buffer", str); |
| } |
| |
| static void snprintf_check(char* str, size_t size, const char* format, ...) |
| { |
| va_list args; |
| |
| va_start(args, format); |
| vsnprintf_check(str, size, format, args); |
| va_end(args); |
| } |
| |
| #define COMMAND_MAX_LEN 128 |
| #define PATH_PREFIX \ |
| "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin " |
| #define PATH_PREFIX_LEN (sizeof(PATH_PREFIX) - 1) |
| |
| static void execute_command(bool panic, const char* format, ...) |
| { |
| va_list args; |
| char command[PATH_PREFIX_LEN + COMMAND_MAX_LEN]; |
| int rv; |
| |
| va_start(args, format); |
| memcpy(command, PATH_PREFIX, PATH_PREFIX_LEN); |
| vsnprintf_check(command + PATH_PREFIX_LEN, COMMAND_MAX_LEN, format, args); |
| rv = system(command); |
| if (panic && rv != 0) |
| fail("tun: command \"%s\" failed with code %d", &command[0], rv); |
| |
| va_end(args); |
| } |
| |
| static int tunfd = -1; |
| static int tun_frags_enabled; |
| |
| #define SYZ_TUN_MAX_PACKET_SIZE 1000 |
| |
| #define MAX_PIDS 32 |
| #define ADDR_MAX_LEN 32 |
| |
| #define LOCAL_MAC "aa:aa:aa:aa:%02hx:aa" |
| #define REMOTE_MAC "aa:aa:aa:aa:%02hx:bb" |
| |
| #define LOCAL_IPV4 "172.20.%d.170" |
| #define REMOTE_IPV4 "172.20.%d.187" |
| |
| #define LOCAL_IPV6 "fe80::%02hx:aa" |
| #define REMOTE_IPV6 "fe80::%02hx:bb" |
| |
| #define IFF_NAPI 0x0010 |
| #define IFF_NAPI_FRAGS 0x0020 |
| |
| static void initialize_tun(int id) |
| { |
| if (id >= MAX_PIDS) |
| fail("tun: no more than %d executors", MAX_PIDS); |
| |
| tunfd = open("/dev/net/tun", O_RDWR | O_NONBLOCK); |
| if (tunfd == -1) { |
| printf("tun: can't open /dev/net/tun: please enable CONFIG_TUN=y\n"); |
| printf("otherwise fuzzing or reproducing might not work as intended\n"); |
| return; |
| } |
| |
| char iface[IFNAMSIZ]; |
| snprintf_check(iface, sizeof(iface), "syz%d", id); |
| |
| struct ifreq ifr; |
| memset(&ifr, 0, sizeof(ifr)); |
| strncpy(ifr.ifr_name, iface, IFNAMSIZ); |
| ifr.ifr_flags = IFF_TAP | IFF_NO_PI | IFF_NAPI | IFF_NAPI_FRAGS; |
| if (ioctl(tunfd, TUNSETIFF, (void*)&ifr) < 0) { |
| ifr.ifr_flags = IFF_TAP | IFF_NO_PI; |
| if (ioctl(tunfd, TUNSETIFF, (void*)&ifr) < 0) |
| fail("tun: ioctl(TUNSETIFF) failed"); |
| } |
| if (ioctl(tunfd, TUNGETIFF, (void*)&ifr) < 0) |
| fail("tun: ioctl(TUNGETIFF) failed"); |
| tun_frags_enabled = (ifr.ifr_flags & IFF_NAPI_FRAGS) != 0; |
| |
| char local_mac[ADDR_MAX_LEN]; |
| snprintf_check(local_mac, sizeof(local_mac), LOCAL_MAC, id); |
| char remote_mac[ADDR_MAX_LEN]; |
| snprintf_check(remote_mac, sizeof(remote_mac), REMOTE_MAC, id); |
| |
| char local_ipv4[ADDR_MAX_LEN]; |
| snprintf_check(local_ipv4, sizeof(local_ipv4), LOCAL_IPV4, id); |
| char remote_ipv4[ADDR_MAX_LEN]; |
| snprintf_check(remote_ipv4, sizeof(remote_ipv4), REMOTE_IPV4, id); |
| |
| char local_ipv6[ADDR_MAX_LEN]; |
| snprintf_check(local_ipv6, sizeof(local_ipv6), LOCAL_IPV6, id); |
| char remote_ipv6[ADDR_MAX_LEN]; |
| snprintf_check(remote_ipv6, sizeof(remote_ipv6), REMOTE_IPV6, id); |
| |
| execute_command(1, "sysctl -w net.ipv6.conf.%s.accept_dad=0", iface); |
| |
| execute_command(1, "sysctl -w net.ipv6.conf.%s.router_solicitations=0", |
| iface); |
| |
| execute_command(1, "ip link set dev %s address %s", iface, local_mac); |
| execute_command(1, "ip addr add %s/24 dev %s", local_ipv4, iface); |
| execute_command(1, "ip -6 addr add %s/120 dev %s", local_ipv6, iface); |
| execute_command(1, "ip neigh add %s lladdr %s dev %s nud permanent", |
| remote_ipv4, remote_mac, iface); |
| execute_command(1, "ip -6 neigh add %s lladdr %s dev %s nud permanent", |
| remote_ipv6, remote_mac, iface); |
| execute_command(1, "ip link set dev %s up", iface); |
| } |
| |
| #define DEV_IPV4 "172.20.%d.%d" |
| #define DEV_IPV6 "fe80::%02hx:%02hx" |
| #define DEV_MAC "aa:aa:aa:aa:%02hx:%02hx" |
| |
| static void initialize_netdevices(int id) |
| { |
| unsigned i; |
| const char* devtypes[] = {"ip6gretap", "bridge", "vcan"}; |
| const char* devnames[] = {"lo", "sit0", "bridge0", "vcan0", |
| "tunl0", "gre0", "gretap0", "ip_vti0", |
| "ip6_vti0", "ip6tnl0", "ip6gre0", "ip6gretap0", |
| "erspan0"}; |
| |
| for (i = 0; i < sizeof(devtypes) / (sizeof(devtypes[0])); i++) |
| execute_command(0, "ip link add dev %s0 type %s", devtypes[i], devtypes[i]); |
| for (i = 0; i < sizeof(devnames) / (sizeof(devnames[0])); i++) { |
| char addr[ADDR_MAX_LEN]; |
| snprintf_check(addr, sizeof(addr), DEV_IPV4, id, id + 10); |
| execute_command(0, "ip -4 addr add %s/24 dev %s", addr, devnames[i]); |
| snprintf_check(addr, sizeof(addr), DEV_IPV6, id, id + 10); |
| execute_command(0, "ip -6 addr add %s/120 dev %s", addr, devnames[i]); |
| snprintf_check(addr, sizeof(addr), DEV_MAC, id, id + 10); |
| execute_command(0, "ip link set dev %s address %s", devnames[i], addr); |
| execute_command(0, "ip link set dev %s up", devnames[i]); |
| } |
| } |
| |
| static void setup_tun(uint64_t pid, bool enable_tun) |
| { |
| if (enable_tun) { |
| initialize_tun(pid); |
| initialize_netdevices(pid); |
| } |
| } |
| |
| #define MAX_FRAGS 4 |
| struct vnet_fragmentation { |
| uint32_t full; |
| uint32_t count; |
| uint32_t frags[MAX_FRAGS]; |
| }; |
| |
| static uintptr_t syz_emit_ethernet(uintptr_t a0, uintptr_t a1, uintptr_t a2) |
| { |
| if (tunfd < 0) |
| return (uintptr_t)-1; |
| |
| uint32_t length = a0; |
| char* data = (char*)a1; |
| |
| struct vnet_fragmentation* frags = (struct vnet_fragmentation*)a2; |
| struct iovec vecs[MAX_FRAGS + 1]; |
| uint32_t nfrags = 0; |
| if (!tun_frags_enabled || frags == NULL) { |
| vecs[nfrags].iov_base = data; |
| vecs[nfrags].iov_len = length; |
| nfrags++; |
| } else { |
| bool full = true; |
| uint32_t i, count = 0; |
| full = frags->full; |
| count = frags->count; |
| if (count > MAX_FRAGS) |
| count = MAX_FRAGS; |
| for (i = 0; i < count && length != 0; i++) { |
| uint32_t size = 0; |
| size = frags->frags[i]; |
| if (size > length) |
| size = length; |
| vecs[nfrags].iov_base = data; |
| vecs[nfrags].iov_len = size; |
| nfrags++; |
| data += size; |
| length -= size; |
| } |
| if (length != 0 && (full || nfrags == 0)) { |
| vecs[nfrags].iov_base = data; |
| vecs[nfrags].iov_len = length; |
| nfrags++; |
| } |
| } |
| return writev(tunfd, vecs, nfrags); |
| } |
| |
| long r[2]; |
| void loop() |
| { |
| memset(r, -1, sizeof(r)); |
| syscall(__NR_mmap, 0x20000000, 0xfff000, 3, 0x32, -1, 0); |
| memcpy((void*)0x20ed0ed5, "\xd7\xec\x06\x00\xff\xff", 6); |
| *(uint8_t*)0x20ed0edb = 0xaa; |
| *(uint8_t*)0x20ed0edc = 0xaa; |
| *(uint8_t*)0x20ed0edd = 0xaa; |
| *(uint8_t*)0x20ed0ede = 0xaa; |
| *(uint8_t*)0x20ed0edf = 0; |
| *(uint8_t*)0x20ed0ee0 = 0; |
| *(uint16_t*)0x20ed0ee1 = htobe16(0x86dd); |
| STORE_BY_BITMASK(uint8_t, 0x20ed0ee3, 0, 0, 4); |
| STORE_BY_BITMASK(uint8_t, 0x20ed0ee3, 6, 4, 4); |
| memcpy((void*)0x20ed0ee4, "\xa5\x08\x07", 3); |
| *(uint16_t*)0x20ed0ee7 = htobe16(8); |
| *(uint8_t*)0x20ed0ee9 = 0x11; |
| *(uint8_t*)0x20ed0eea = 0; |
| *(uint8_t*)0x20ed0eeb = 0xfe; |
| *(uint8_t*)0x20ed0eec = 0x80; |
| *(uint8_t*)0x20ed0eed = 0; |
| *(uint8_t*)0x20ed0eee = 0; |
| *(uint8_t*)0x20ed0eef = 0; |
| *(uint8_t*)0x20ed0ef0 = 0; |
| *(uint8_t*)0x20ed0ef1 = 0; |
| *(uint8_t*)0x20ed0ef2 = 0; |
| *(uint8_t*)0x20ed0ef3 = 0; |
| *(uint8_t*)0x20ed0ef4 = 0; |
| *(uint8_t*)0x20ed0ef5 = 0; |
| *(uint8_t*)0x20ed0ef6 = 0; |
| *(uint8_t*)0x20ed0ef7 = 0; |
| *(uint8_t*)0x20ed0ef8 = 0; |
| *(uint8_t*)0x20ed0ef9 = 0; |
| *(uint8_t*)0x20ed0efa = 0xbb; |
| *(uint8_t*)0x20ed0efb = -1; |
| *(uint8_t*)0x20ed0efc = 2; |
| *(uint8_t*)0x20ed0efd = 0; |
| *(uint8_t*)0x20ed0efe = 0; |
| *(uint8_t*)0x20ed0eff = 0; |
| *(uint8_t*)0x20ed0f00 = 0; |
| *(uint8_t*)0x20ed0f01 = 0; |
| *(uint8_t*)0x20ed0f02 = 0; |
| *(uint8_t*)0x20ed0f03 = 0; |
| *(uint8_t*)0x20ed0f04 = 0; |
| *(uint8_t*)0x20ed0f05 = 0; |
| *(uint8_t*)0x20ed0f06 = 0; |
| *(uint8_t*)0x20ed0f07 = 0; |
| *(uint8_t*)0x20ed0f08 = 0; |
| *(uint8_t*)0x20ed0f09 = 0; |
| *(uint8_t*)0x20ed0f0a = 1; |
| *(uint16_t*)0x20ed0f0b = 0; |
| *(uint16_t*)0x20ed0f0d = htobe16(0x4e22); |
| *(uint16_t*)0x20ed0f0f = htobe16(8); |
| *(uint16_t*)0x20ed0f11 = 0; |
| struct csum_inet csum_1; |
| csum_inet_init(&csum_1); |
| csum_inet_update(&csum_1, (const uint8_t*)0x20ed0eeb, 16); |
| csum_inet_update(&csum_1, (const uint8_t*)0x20ed0efb, 16); |
| uint32_t csum_1_chunk_2 = 0x8000000; |
| csum_inet_update(&csum_1, (const uint8_t*)&csum_1_chunk_2, 4); |
| uint32_t csum_1_chunk_3 = 0x11000000; |
| csum_inet_update(&csum_1, (const uint8_t*)&csum_1_chunk_3, 4); |
| csum_inet_update(&csum_1, (const uint8_t*)0x20ed0f0b, 8); |
| *(uint16_t*)0x20ed0f11 = csum_inet_digest(&csum_1); |
| syz_emit_ethernet(0x3e, 0x20ed0ed5, 0x20000000); |
| r[0] = syscall(__NR_socket, 0x10, 2, 0); |
| *(uint8_t*)0x20184000 = 0x73; |
| *(uint8_t*)0x20184001 = 0x79; |
| *(uint8_t*)0x20184002 = 0x7a; |
| *(uint8_t*)0x20184003 = 0x30; |
| *(uint8_t*)0x20184004 = 0; |
| *(uint32_t*)0x20184010 = 0; |
| *(uint8_t*)0x20184014 = 0; |
| *(uint8_t*)0x20184015 = 0; |
| *(uint8_t*)0x20184016 = 0; |
| *(uint8_t*)0x20184017 = 0; |
| *(uint8_t*)0x20184018 = 0; |
| *(uint8_t*)0x20184019 = 0; |
| *(uint8_t*)0x2018401a = 0; |
| *(uint8_t*)0x2018401b = 0; |
| *(uint8_t*)0x2018401c = 0; |
| *(uint8_t*)0x2018401d = 0; |
| *(uint8_t*)0x2018401e = 0; |
| *(uint8_t*)0x2018401f = 0; |
| *(uint8_t*)0x20184020 = 0; |
| *(uint8_t*)0x20184021 = 0; |
| *(uint8_t*)0x20184022 = 0; |
| *(uint8_t*)0x20184023 = 0; |
| *(uint8_t*)0x20184024 = 0; |
| *(uint8_t*)0x20184025 = 0; |
| *(uint8_t*)0x20184026 = 0; |
| *(uint8_t*)0x20184027 = 0; |
| if (syscall(__NR_ioctl, r[0], 0x8933, 0x20184000) != -1) |
| r[1] = *(uint32_t*)0x20184010; |
| *(uint64_t*)0x20bf6000 = 0x20ba2ff4; |
| *(uint32_t*)0x20bf6008 = 0xc; |
| *(uint64_t*)0x20bf6010 = 0x20434ff0; |
| *(uint64_t*)0x20bf6018 = 1; |
| *(uint64_t*)0x20bf6020 = 0; |
| *(uint64_t*)0x20bf6028 = 0; |
| *(uint32_t*)0x20bf6030 = 0; |
| *(uint16_t*)0x20ba2ff4 = 0x10; |
| *(uint16_t*)0x20ba2ff6 = 0; |
| *(uint32_t*)0x20ba2ff8 = 0; |
| *(uint32_t*)0x20ba2ffc = 0; |
| *(uint64_t*)0x20434ff0 = 0x201a4000; |
| *(uint64_t*)0x20434ff8 = 0x30; |
| *(uint32_t*)0x201a4000 = 0x30; |
| *(uint16_t*)0x201a4004 = 0x10; |
| *(uint16_t*)0x201a4006 = 9; |
| *(uint32_t*)0x201a4008 = 0; |
| *(uint32_t*)0x201a400c = 0; |
| *(uint8_t*)0x201a4010 = 0; |
| *(uint8_t*)0x201a4011 = 0; |
| *(uint16_t*)0x201a4012 = 0; |
| *(uint32_t*)0x201a4014 = r[1]; |
| *(uint32_t*)0x201a4018 = 0; |
| *(uint32_t*)0x201a401c = 0; |
| *(uint16_t*)0x201a4020 = 8; |
| *(uint16_t*)0x201a4022 = 0xd; |
| *(uint32_t*)0x201a4024 = -1; |
| *(uint16_t*)0x201a4028 = 8; |
| *(uint16_t*)0x201a402a = 0x16; |
| *(uint16_t*)0x201a402c = 4; |
| *(uint16_t*)0x201a402e = 1; |
| syscall(__NR_sendmsg, r[0], 0x20bf6000, 0); |
| } |
| |
| int main() |
| { |
| setup_tun(0, true); |
| loop(); |
| return 0; |
| } |