// https://syzkaller.appspot.com/bug?id=2f3bb444cf8f5e32469353a19ac6519d87b885dc // 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include unsigned long long procid; 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; } struct nlmsg { char* pos; int nesting; struct nlattr* nested[8]; char buf[1024]; }; static struct nlmsg nlmsg; 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; memcpy(attr + 1, data, size); nlmsg->pos += NLMSG_ALIGN(attr->nla_len); } static void netlink_nest(struct nlmsg* nlmsg, int typ) { struct nlattr* attr = (struct nlattr*)nlmsg->pos; attr->nla_type = typ; nlmsg->pos += sizeof(*attr); nlmsg->nested[nlmsg->nesting++] = attr; } static void netlink_done(struct nlmsg* nlmsg) { struct nlattr* attr = nlmsg->nested[--nlmsg->nesting]; attr->nla_len = nlmsg->pos - (char*)attr; } static int netlink_send_ext(struct nlmsg* nlmsg, int sock, uint16_t reply_type, int* reply_len) { 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; unsigned n = sendto(sock, nlmsg->buf, hdr->nlmsg_len, 0, (struct sockaddr*)&addr, sizeof(addr)); if (n != hdr->nlmsg_len) exit(1); n = recv(sock, nlmsg->buf, sizeof(nlmsg->buf), 0); if (hdr->nlmsg_type == NLMSG_DONE) { *reply_len = 0; return 0; } if (n < sizeof(struct nlmsghdr)) exit(1); if (reply_len && hdr->nlmsg_type == reply_type) { *reply_len = n; return 0; } if (n < sizeof(struct nlmsghdr) + sizeof(struct nlmsgerr)) exit(1); if (hdr->nlmsg_type != NLMSG_ERROR) exit(1); return -((struct nlmsgerr*)(hdr + 1))->error; } static int netlink_send(struct nlmsg* nlmsg, int sock) { return netlink_send_ext(nlmsg, sock, 0, NULL); } static int netlink_next_msg(struct nlmsg* nlmsg, unsigned int offset, unsigned int total_len) { struct nlmsghdr* hdr = (struct nlmsghdr*)(nlmsg->buf + offset); if (offset == total_len || offset + hdr->nlmsg_len > total_len) return -1; return hdr->nlmsg_len; } static void netlink_add_device_impl(struct nlmsg* nlmsg, const char* type, const char* name) { struct ifinfomsg hdr; memset(&hdr, 0, sizeof(hdr)); netlink_init(nlmsg, RTM_NEWLINK, NLM_F_EXCL | NLM_F_CREATE, &hdr, sizeof(hdr)); if (name) netlink_attr(nlmsg, IFLA_IFNAME, name, strlen(name)); netlink_nest(nlmsg, IFLA_LINKINFO); netlink_attr(nlmsg, IFLA_INFO_KIND, type, strlen(type)); } static void netlink_add_device(struct nlmsg* nlmsg, int sock, const char* type, const char* name) { netlink_add_device_impl(nlmsg, type, name); netlink_done(nlmsg); int err = netlink_send(nlmsg, sock); (void)err; } static void netlink_add_veth(struct nlmsg* nlmsg, int sock, const char* name, const char* peer) { netlink_add_device_impl(nlmsg, "veth", name); netlink_nest(nlmsg, IFLA_INFO_DATA); netlink_nest(nlmsg, VETH_INFO_PEER); nlmsg->pos += sizeof(struct ifinfomsg); netlink_attr(nlmsg, IFLA_IFNAME, peer, strlen(peer)); netlink_done(nlmsg); netlink_done(nlmsg); netlink_done(nlmsg); int err = netlink_send(nlmsg, sock); (void)err; } static void netlink_add_hsr(struct nlmsg* nlmsg, int sock, const char* name, const char* slave1, const char* slave2) { netlink_add_device_impl(nlmsg, "hsr", name); netlink_nest(nlmsg, IFLA_INFO_DATA); int ifindex1 = if_nametoindex(slave1); netlink_attr(nlmsg, IFLA_HSR_SLAVE1, &ifindex1, sizeof(ifindex1)); int ifindex2 = if_nametoindex(slave2); netlink_attr(nlmsg, IFLA_HSR_SLAVE2, &ifindex2, sizeof(ifindex2)); netlink_done(nlmsg); netlink_done(nlmsg); int err = netlink_send(nlmsg, sock); (void)err; } static void netlink_add_virt_wifi(struct nlmsg* nlmsg, int sock, const char* name, const char* link) { netlink_add_device_impl(nlmsg, "virt_wifi", name); netlink_done(nlmsg); int ifindex = if_nametoindex(link); netlink_attr(nlmsg, IFLA_LINK, &ifindex, sizeof(ifindex)); int err = netlink_send(nlmsg, sock); (void)err; } static void netlink_add_vlan(struct nlmsg* nlmsg, int sock, const char* name, const char* link, uint16_t id, uint16_t proto) { netlink_add_device_impl(nlmsg, "vlan", name); netlink_nest(nlmsg, IFLA_INFO_DATA); netlink_attr(nlmsg, IFLA_VLAN_ID, &id, sizeof(id)); netlink_attr(nlmsg, IFLA_VLAN_PROTOCOL, &proto, sizeof(proto)); netlink_done(nlmsg); netlink_done(nlmsg); int ifindex = if_nametoindex(link); netlink_attr(nlmsg, IFLA_LINK, &ifindex, sizeof(ifindex)); int err = netlink_send(nlmsg, sock); (void)err; } static void netlink_add_macvlan(struct nlmsg* nlmsg, int sock, const char* name, const char* link) { netlink_add_device_impl(nlmsg, "macvlan", name); netlink_nest(nlmsg, IFLA_INFO_DATA); uint32_t mode = MACVLAN_MODE_BRIDGE; netlink_attr(nlmsg, IFLA_MACVLAN_MODE, &mode, sizeof(mode)); netlink_done(nlmsg); netlink_done(nlmsg); int ifindex = if_nametoindex(link); netlink_attr(nlmsg, IFLA_LINK, &ifindex, sizeof(ifindex)); int err = netlink_send(nlmsg, sock); (void)err; } #define IFLA_IPVLAN_FLAGS 2 #define IPVLAN_MODE_L3S 2 #undef IPVLAN_F_VEPA #define IPVLAN_F_VEPA 2 static void netlink_add_ipvlan(struct nlmsg* nlmsg, int sock, const char* name, const char* link, uint16_t mode, uint16_t flags) { netlink_add_device_impl(nlmsg, "ipvlan", name); netlink_nest(nlmsg, IFLA_INFO_DATA); netlink_attr(nlmsg, IFLA_IPVLAN_MODE, &mode, sizeof(mode)); netlink_attr(nlmsg, IFLA_IPVLAN_FLAGS, &flags, sizeof(flags)); netlink_done(nlmsg); netlink_done(nlmsg); int ifindex = if_nametoindex(link); netlink_attr(nlmsg, IFLA_LINK, &ifindex, sizeof(ifindex)); int err = netlink_send(nlmsg, sock); (void)err; } static void netlink_device_change(struct nlmsg* nlmsg, int sock, const char* name, bool up, const char* master, const void* mac, int macsize, const char* new_name) { struct ifinfomsg hdr; memset(&hdr, 0, sizeof(hdr)); if (up) hdr.ifi_flags = hdr.ifi_change = IFF_UP; hdr.ifi_index = if_nametoindex(name); netlink_init(nlmsg, RTM_NEWLINK, 0, &hdr, sizeof(hdr)); if (new_name) netlink_attr(nlmsg, IFLA_IFNAME, new_name, strlen(new_name)); if (master) { int ifindex = if_nametoindex(master); netlink_attr(nlmsg, IFLA_MASTER, &ifindex, sizeof(ifindex)); } if (macsize) netlink_attr(nlmsg, IFLA_ADDRESS, mac, macsize); int err = netlink_send(nlmsg, sock); (void)err; } static int netlink_add_addr(struct nlmsg* nlmsg, int sock, const char* dev, const void* addr, int addrsize) { struct ifaddrmsg hdr; memset(&hdr, 0, sizeof(hdr)); hdr.ifa_family = addrsize == 4 ? AF_INET : AF_INET6; hdr.ifa_prefixlen = addrsize == 4 ? 24 : 120; hdr.ifa_scope = RT_SCOPE_UNIVERSE; hdr.ifa_index = if_nametoindex(dev); netlink_init(nlmsg, RTM_NEWADDR, NLM_F_CREATE | NLM_F_REPLACE, &hdr, sizeof(hdr)); netlink_attr(nlmsg, IFA_LOCAL, addr, addrsize); netlink_attr(nlmsg, IFA_ADDRESS, addr, addrsize); return netlink_send(nlmsg, sock); } static void netlink_add_addr4(struct nlmsg* nlmsg, int sock, const char* dev, const char* addr) { struct in_addr in_addr; inet_pton(AF_INET, addr, &in_addr); int err = netlink_add_addr(nlmsg, sock, dev, &in_addr, sizeof(in_addr)); (void)err; } static void netlink_add_addr6(struct nlmsg* nlmsg, int sock, const char* dev, const char* addr) { struct in6_addr in6_addr; inet_pton(AF_INET6, addr, &in6_addr); int err = netlink_add_addr(nlmsg, sock, dev, &in6_addr, sizeof(in6_addr)); (void)err; } static void netlink_add_neigh(struct nlmsg* nlmsg, int sock, const char* name, const void* addr, int addrsize, const void* mac, int macsize) { struct ndmsg hdr; memset(&hdr, 0, sizeof(hdr)); hdr.ndm_family = addrsize == 4 ? AF_INET : AF_INET6; hdr.ndm_ifindex = if_nametoindex(name); hdr.ndm_state = NUD_PERMANENT; netlink_init(nlmsg, RTM_NEWNEIGH, NLM_F_EXCL | NLM_F_CREATE, &hdr, sizeof(hdr)); netlink_attr(nlmsg, NDA_DST, addr, addrsize); netlink_attr(nlmsg, NDA_LLADDR, mac, macsize); int err = netlink_send(nlmsg, sock); (void)err; } static int tunfd = -1; static int tun_frags_enabled; #define TUN_IFACE "syz_tun" #define LOCAL_MAC 0xaaaaaaaaaaaa #define REMOTE_MAC 0xaaaaaaaaaabb #define LOCAL_IPV4 "172.20.20.170" #define REMOTE_IPV4 "172.20.20.187" #define LOCAL_IPV6 "fe80::aa" #define REMOTE_IPV6 "fe80::bb" #define IFF_NAPI 0x0010 #define IFF_NAPI_FRAGS 0x0020 static void initialize_tun(void) { 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; } const int kTunFd = 240; if (dup2(tunfd, kTunFd) < 0) exit(1); close(tunfd); tunfd = kTunFd; struct ifreq ifr; memset(&ifr, 0, sizeof(ifr)); strncpy(ifr.ifr_name, TUN_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) exit(1); } if (ioctl(tunfd, TUNGETIFF, (void*)&ifr) < 0) exit(1); tun_frags_enabled = (ifr.ifr_flags & IFF_NAPI_FRAGS) != 0; char sysctl[64]; sprintf(sysctl, "/proc/sys/net/ipv6/conf/%s/accept_dad", TUN_IFACE); write_file(sysctl, "0"); sprintf(sysctl, "/proc/sys/net/ipv6/conf/%s/router_solicitations", TUN_IFACE); write_file(sysctl, "0"); int sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); if (sock == -1) exit(1); netlink_add_addr4(&nlmsg, sock, TUN_IFACE, LOCAL_IPV4); netlink_add_addr6(&nlmsg, sock, TUN_IFACE, LOCAL_IPV6); uint64_t macaddr = REMOTE_MAC; struct in_addr in_addr; inet_pton(AF_INET, REMOTE_IPV4, &in_addr); netlink_add_neigh(&nlmsg, sock, TUN_IFACE, &in_addr, sizeof(in_addr), &macaddr, ETH_ALEN); struct in6_addr in6_addr; inet_pton(AF_INET6, REMOTE_IPV6, &in6_addr); netlink_add_neigh(&nlmsg, sock, TUN_IFACE, &in6_addr, sizeof(in6_addr), &macaddr, ETH_ALEN); macaddr = LOCAL_MAC; netlink_device_change(&nlmsg, sock, TUN_IFACE, true, 0, &macaddr, ETH_ALEN, NULL); close(sock); } #define DEVLINK_FAMILY_NAME "devlink" #define DEVLINK_CMD_PORT_GET 5 #define DEVLINK_ATTR_BUS_NAME 1 #define DEVLINK_ATTR_DEV_NAME 2 #define DEVLINK_ATTR_NETDEV_NAME 7 static int netlink_devlink_id_get(struct nlmsg* nlmsg, int sock) { struct genlmsghdr genlhdr; struct nlattr* attr; int err, n; uint16_t id = 0; 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, DEVLINK_FAMILY_NAME, strlen(DEVLINK_FAMILY_NAME) + 1); err = netlink_send_ext(nlmsg, sock, GENL_ID_CTRL, &n); if (err) { return -1; } 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) { return -1; } recv(sock, nlmsg->buf, sizeof(nlmsg->buf), 0); /* recv ack */ return id; } static struct nlmsg nlmsg2; static void initialize_devlink_ports(const char* bus_name, const char* dev_name, const char* netdev_prefix) { struct genlmsghdr genlhdr; int len, total_len, id, err, offset; uint16_t netdev_index; int sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC); if (sock == -1) exit(1); int rtsock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); if (rtsock == -1) exit(1); id = netlink_devlink_id_get(&nlmsg, sock); if (id == -1) goto error; memset(&genlhdr, 0, sizeof(genlhdr)); genlhdr.cmd = DEVLINK_CMD_PORT_GET; netlink_init(&nlmsg, id, NLM_F_DUMP, &genlhdr, sizeof(genlhdr)); netlink_attr(&nlmsg, DEVLINK_ATTR_BUS_NAME, bus_name, strlen(bus_name) + 1); netlink_attr(&nlmsg, DEVLINK_ATTR_DEV_NAME, dev_name, strlen(dev_name) + 1); err = netlink_send_ext(&nlmsg, sock, id, &total_len); if (err) { goto error; } offset = 0; netdev_index = 0; while ((len = netlink_next_msg(&nlmsg, offset, total_len)) != -1) { struct nlattr* attr = (struct nlattr*)(nlmsg.buf + offset + NLMSG_HDRLEN + NLMSG_ALIGN(sizeof(genlhdr))); for (; (char*)attr < nlmsg.buf + offset + len; attr = (struct nlattr*)((char*)attr + NLMSG_ALIGN(attr->nla_len))) { if (attr->nla_type == DEVLINK_ATTR_NETDEV_NAME) { char* port_name; char netdev_name[IFNAMSIZ]; port_name = (char*)(attr + 1); snprintf(netdev_name, sizeof(netdev_name), "%s%d", netdev_prefix, netdev_index); netlink_device_change(&nlmsg2, rtsock, port_name, true, 0, 0, 0, netdev_name); break; } } offset += len; netdev_index++; } error: close(rtsock); close(sock); } #define DEV_IPV4 "172.20.20.%d" #define DEV_IPV6 "fe80::%02x" #define DEV_MAC 0x00aaaaaaaaaa static void netdevsim_add(unsigned int addr, unsigned int port_count) { char buf[16]; sprintf(buf, "%u %u", addr, port_count); if (write_file("/sys/bus/netdevsim/new_device", buf)) { snprintf(buf, sizeof(buf), "netdevsim%d", addr); initialize_devlink_ports("netdevsim", buf, "netdevsim"); } } static void initialize_netdevices(void) { char netdevsim[16]; sprintf(netdevsim, "netdevsim%d", (int)procid); struct { const char* type; const char* dev; } devtypes[] = { {"ip6gretap", "ip6gretap0"}, {"bridge", "bridge0"}, {"vcan", "vcan0"}, {"bond", "bond0"}, {"team", "team0"}, {"dummy", "dummy0"}, {"nlmon", "nlmon0"}, {"caif", "caif0"}, {"batadv", "batadv0"}, {"vxcan", "vxcan1"}, {"netdevsim", netdevsim}, {"veth", 0}, {"xfrm", "xfrm0"}, }; const char* devmasters[] = {"bridge", "bond", "team"}; struct { const char* name; int macsize; bool noipv6; } devices[] = { {"lo", ETH_ALEN}, {"sit0", 0}, {"bridge0", ETH_ALEN}, {"vcan0", 0, true}, {"tunl0", 0}, {"gre0", 0}, {"gretap0", ETH_ALEN}, {"ip_vti0", 0}, {"ip6_vti0", 0}, {"ip6tnl0", 0}, {"ip6gre0", 0}, {"ip6gretap0", ETH_ALEN}, {"erspan0", ETH_ALEN}, {"bond0", ETH_ALEN}, {"veth0", ETH_ALEN}, {"veth1", ETH_ALEN}, {"team0", ETH_ALEN}, {"veth0_to_bridge", ETH_ALEN}, {"veth1_to_bridge", ETH_ALEN}, {"veth0_to_bond", ETH_ALEN}, {"veth1_to_bond", ETH_ALEN}, {"veth0_to_team", ETH_ALEN}, {"veth1_to_team", ETH_ALEN}, {"veth0_to_hsr", ETH_ALEN}, {"veth1_to_hsr", ETH_ALEN}, {"hsr0", 0}, {"dummy0", ETH_ALEN}, {"nlmon0", 0}, {"vxcan0", 0, true}, {"vxcan1", 0, true}, {"caif0", ETH_ALEN}, {"batadv0", ETH_ALEN}, {netdevsim, ETH_ALEN}, {"xfrm0", ETH_ALEN}, {"veth0_virt_wifi", ETH_ALEN}, {"veth1_virt_wifi", ETH_ALEN}, {"virt_wifi0", ETH_ALEN}, {"veth0_vlan", ETH_ALEN}, {"veth1_vlan", ETH_ALEN}, {"vlan0", ETH_ALEN}, {"vlan1", ETH_ALEN}, {"macvlan0", ETH_ALEN}, {"macvlan1", ETH_ALEN}, {"ipvlan0", ETH_ALEN}, {"ipvlan1", ETH_ALEN}, }; int sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); if (sock == -1) exit(1); unsigned i; for (i = 0; i < sizeof(devtypes) / sizeof(devtypes[0]); i++) netlink_add_device(&nlmsg, sock, devtypes[i].type, devtypes[i].dev); for (i = 0; i < sizeof(devmasters) / (sizeof(devmasters[0])); i++) { char master[32], slave0[32], veth0[32], slave1[32], veth1[32]; sprintf(slave0, "%s_slave_0", devmasters[i]); sprintf(veth0, "veth0_to_%s", devmasters[i]); netlink_add_veth(&nlmsg, sock, slave0, veth0); sprintf(slave1, "%s_slave_1", devmasters[i]); sprintf(veth1, "veth1_to_%s", devmasters[i]); netlink_add_veth(&nlmsg, sock, slave1, veth1); sprintf(master, "%s0", devmasters[i]); netlink_device_change(&nlmsg, sock, slave0, false, master, 0, 0, NULL); netlink_device_change(&nlmsg, sock, slave1, false, master, 0, 0, NULL); } netlink_device_change(&nlmsg, sock, "bridge_slave_0", true, 0, 0, 0, NULL); netlink_device_change(&nlmsg, sock, "bridge_slave_1", true, 0, 0, 0, NULL); netlink_add_veth(&nlmsg, sock, "hsr_slave_0", "veth0_to_hsr"); netlink_add_veth(&nlmsg, sock, "hsr_slave_1", "veth1_to_hsr"); netlink_add_hsr(&nlmsg, sock, "hsr0", "hsr_slave_0", "hsr_slave_1"); netlink_device_change(&nlmsg, sock, "hsr_slave_0", true, 0, 0, 0, NULL); netlink_device_change(&nlmsg, sock, "hsr_slave_1", true, 0, 0, 0, NULL); netlink_add_veth(&nlmsg, sock, "veth0_virt_wifi", "veth1_virt_wifi"); netlink_add_virt_wifi(&nlmsg, sock, "virt_wifi0", "veth1_virt_wifi"); netlink_add_veth(&nlmsg, sock, "veth0_vlan", "veth1_vlan"); netlink_add_vlan(&nlmsg, sock, "vlan0", "veth0_vlan", 0, htons(ETH_P_8021Q)); netlink_add_vlan(&nlmsg, sock, "vlan1", "veth0_vlan", 1, htons(ETH_P_8021AD)); netlink_add_macvlan(&nlmsg, sock, "macvlan0", "veth1_vlan"); netlink_add_macvlan(&nlmsg, sock, "macvlan1", "veth1_vlan"); netlink_add_ipvlan(&nlmsg, sock, "ipvlan0", "veth0_vlan", IPVLAN_MODE_L2, 0); netlink_add_ipvlan(&nlmsg, sock, "ipvlan1", "veth0_vlan", IPVLAN_MODE_L3S, IPVLAN_F_VEPA); netdevsim_add((int)procid, 4); for (i = 0; i < sizeof(devices) / (sizeof(devices[0])); i++) { char addr[32]; sprintf(addr, DEV_IPV4, i + 10); netlink_add_addr4(&nlmsg, sock, devices[i].name, addr); if (!devices[i].noipv6) { sprintf(addr, DEV_IPV6, i + 10); netlink_add_addr6(&nlmsg, sock, devices[i].name, addr); } uint64_t macaddr = DEV_MAC + ((i + 10ull) << 40); netlink_device_change(&nlmsg, sock, devices[i].name, true, 0, &macaddr, devices[i].macsize, NULL); } close(sock); } static void initialize_netdevices_init(void) { int sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE); if (sock == -1) exit(1); struct { const char* type; int macsize; bool noipv6; bool noup; } devtypes[] = { {"nr", 7, true}, {"rose", 5, true, true}, }; unsigned i; for (i = 0; i < sizeof(devtypes) / sizeof(devtypes[0]); i++) { char dev[32], addr[32]; sprintf(dev, "%s%d", devtypes[i].type, (int)procid); sprintf(addr, "172.30.%d.%d", i, (int)procid + 1); netlink_add_addr4(&nlmsg, sock, dev, addr); if (!devtypes[i].noipv6) { sprintf(addr, "fe88::%02x:%02x", i, (int)procid + 1); netlink_add_addr6(&nlmsg, sock, dev, addr); } int macsize = devtypes[i].macsize; uint64_t macaddr = 0xbbbbbb + ((unsigned long long)i << (8 * (macsize - 2))) + (procid << (8 * (macsize - 1))); netlink_device_change(&nlmsg, sock, dev, !devtypes[i].noup, 0, &macaddr, macsize, NULL); } close(sock); } static int read_tun(char* data, int size) { if (tunfd < 0) return -1; int rv = read(tunfd, data, size); if (rv < 0) { if (errno == EAGAIN) return -1; if (errno == EBADFD) return -1; exit(1); } return rv; } static void flush_tun() { char data[1000]; while (read_tun(&data[0], sizeof(data)) != -1) { } } #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); setpgrp(); 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 (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); } 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(); initialize_netdevices_init(); if (unshare(CLONE_NEWNET)) { } initialize_tun(); initialize_netdevices(); loop(); exit(1); } static void kill_and_wait(int pid, int* status) { kill(-pid, SIGKILL); kill(pid, SIGKILL); int i; for (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"); flush_tun(); } static void close_fds() { int fd; for (fd = 3; fd < MAX_FDS; fd++) close(fd); } static void execute_one(void); #define WAIT_FLAGS __WALL static void loop(void) { int iter; for (iter = 0;; iter++) { int pid = fork(); if (pid < 0) exit(1); if (pid == 0) { 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 < 5 * 1000) continue; kill_and_wait(pid, &status); break; } } } uint64_t r[6] = {0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff, 0xffffffffffffffff}; void execute_one(void) { intptr_t res = 0; res = syscall(__NR_socketpair, 1ul, 1ul, 0ul, 0x20000000ul); if (res != -1) r[0] = *(uint32_t*)0x20000004; res = syscall(__NR_socket, 0x10ul, 3ul, 0ul); if (res != -1) r[1] = res; memcpy((void*)0x20000340, "erspan0\000\000\000\000\000\000\000\000\000", 16); *(uint32_t*)0x20000350 = 0; res = syscall(__NR_ioctl, r[0], 0x8933ul, 0x20000340ul); if (res != -1) r[2] = *(uint32_t*)0x20000350; syscall(__NR_socket, 0x10ul, 3ul, 0ul); res = syscall(__NR_socket, 0x10ul, 3ul, 0ul); if (res != -1) r[3] = res; res = syscall(__NR_socket, 0x10ul, 0x803ul, 0); if (res != -1) r[4] = res; *(uint64_t*)0x200001c0 = 0; *(uint32_t*)0x200001c8 = 0; *(uint64_t*)0x200001d0 = 0x20000180; *(uint64_t*)0x20000180 = 0; *(uint64_t*)0x20000188 = 0; *(uint64_t*)0x200001d8 = 1; *(uint64_t*)0x200001e0 = 0; *(uint64_t*)0x200001e8 = 0; *(uint32_t*)0x200001f0 = 0; syscall(__NR_sendmsg, r[4], 0x200001c0ul, 0ul); *(uint32_t*)0x20000200 = 0x14; res = syscall(__NR_getsockname, r[4], 0x20000100ul, 0x20000200ul); if (res != -1) r[5] = *(uint32_t*)0x20000104; *(uint64_t*)0x20000180 = 0; *(uint32_t*)0x20000188 = 0; *(uint64_t*)0x20000190 = 0x200000c0; *(uint64_t*)0x200000c0 = 0x20000380; *(uint32_t*)0x20000380 = 0x3c; *(uint16_t*)0x20000384 = 0x10; *(uint16_t*)0x20000386 = 0x401; *(uint32_t*)0x20000388 = 0; *(uint32_t*)0x2000038c = 0; *(uint8_t*)0x20000390 = 0; *(uint8_t*)0x20000391 = 0; *(uint16_t*)0x20000392 = 0; *(uint32_t*)0x20000394 = r[5]; *(uint32_t*)0x20000398 = 0; *(uint32_t*)0x2000039c = 0; *(uint16_t*)0x200003a0 = 0x1c; *(uint16_t*)0x200003a2 = 0x12; *(uint16_t*)0x200003a4 = 0xc; *(uint16_t*)0x200003a6 = 1; memcpy((void*)0x200003a8, "bridge\000", 7); *(uint16_t*)0x200003b0 = 0xc; *(uint16_t*)0x200003b2 = 2; *(uint16_t*)0x200003b4 = 8; *(uint16_t*)0x200003b6 = 7; *(uint8_t*)0x200003b8 = 5; *(uint64_t*)0x200000c8 = 0x3c; *(uint64_t*)0x20000198 = 1; *(uint64_t*)0x200001a0 = 0; *(uint64_t*)0x200001a8 = 0; *(uint32_t*)0x200001b0 = 0; syscall(__NR_sendmsg, r[3], 0x20000180ul, 0ul); *(uint64_t*)0x20000140 = 0; *(uint32_t*)0x20000148 = 0; *(uint64_t*)0x20000150 = 0x200006c0; *(uint64_t*)0x200006c0 = 0x200000c0; memcpy((void*)0x200000c0, "\x28\x00\x00\x00\x10\x00\x01\x04\x00\x00\x40\x00" "\x00\x00\x00\x00\x00\x00\x1e\xa6", 20); *(uint32_t*)0x200000d4 = r[2]; memcpy((void*)0x200000d8, "\000\000\000\000\000\000\000\000\b\000\n\000", 12); *(uint32_t*)0x200000e4 = r[5]; *(uint64_t*)0x200006c8 = 0x28; *(uint64_t*)0x20000158 = 1; *(uint64_t*)0x20000160 = 0; *(uint64_t*)0x20000168 = 0; *(uint32_t*)0x20000170 = 0; syscall(__NR_sendmsg, r[1], 0x20000140ul, 0ul); } int main(void) { syscall(__NR_mmap, 0x20000000ul, 0x1000000ul, 3ul, 0x32ul, -1, 0); do_sandbox_none(); return 0; }