| // KASAN: use-after-free Read in ip6_xmit |
| // https://syzkaller.appspot.com/bug?id=8af2597890938b642c3bf44a85859691fb9d5cfa |
| // status:fixed |
| // autogenerated by syzkaller (http://github.com/google/syzkaller) |
| |
| #define _GNU_SOURCE |
| #include <arpa/inet.h> |
| #include <endian.h> |
| #include <errno.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <fcntl.h> |
| #include <linux/capability.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 <sched.h> |
| #include <signal.h> |
| #include <stdarg.h> |
| #include <stdarg.h> |
| #include <stdbool.h> |
| #include <stdbool.h> |
| #include <stdio.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <sys/ioctl.h> |
| #include <sys/mman.h> |
| #include <sys/mount.h> |
| #include <sys/prctl.h> |
| #include <sys/resource.h> |
| #include <sys/stat.h> |
| #include <sys/stat.h> |
| #include <sys/syscall.h> |
| #include <sys/time.h> |
| #include <sys/uio.h> |
| #include <sys/wait.h> |
| #include <unistd.h> |
| |
| __attribute__((noreturn)) static void doexit(int status) |
| { |
| volatile unsigned i; |
| syscall(__NR_exit_group, status); |
| for (i = 0;; i++) { |
| } |
| } |
| #include <errno.h> |
| #include <stdarg.h> |
| #include <stdint.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/stat.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); |
| } |
| |
| static void use_temporary_dir() |
| { |
| char tmpdir_template[] = "./syzkaller.XXXXXX"; |
| char* tmpdir = mkdtemp(tmpdir_template); |
| if (!tmpdir) |
| fail("failed to mkdtemp"); |
| if (chmod(tmpdir, 0777)) |
| fail("failed to chmod"); |
| if (chdir(tmpdir)) |
| fail("failed to chdir"); |
| } |
| |
| 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 TUN_IFACE "syz_tun" |
| |
| #define LOCAL_MAC "aa:aa:aa:aa:aa:aa" |
| #define REMOTE_MAC "aa:aa:aa:aa:aa:bb" |
| |
| #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 = 252; |
| if (dup2(tunfd, kTunFd) < 0) |
| fail("dup2(tunfd, kTunFd) failed"); |
| 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) |
| 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; |
| |
| execute_command(1, "sysctl -w net.ipv6.conf.%s.accept_dad=0", TUN_IFACE); |
| |
| execute_command(1, "sysctl -w net.ipv6.conf.%s.router_solicitations=0", |
| TUN_IFACE); |
| |
| execute_command(1, "ip link set dev %s address %s", TUN_IFACE, LOCAL_MAC); |
| execute_command(1, "ip addr add %s/24 dev %s", LOCAL_IPV4, TUN_IFACE); |
| execute_command(1, "ip -6 addr add %s/120 dev %s", LOCAL_IPV6, TUN_IFACE); |
| execute_command(1, "ip neigh add %s lladdr %s dev %s nud permanent", |
| REMOTE_IPV4, REMOTE_MAC, TUN_IFACE); |
| execute_command(1, "ip -6 neigh add %s lladdr %s dev %s nud permanent", |
| REMOTE_IPV6, REMOTE_MAC, TUN_IFACE); |
| execute_command(1, "ip link set dev %s up", TUN_IFACE); |
| } |
| |
| #define DEV_IPV4 "172.20.20.%d" |
| #define DEV_IPV6 "fe80::%02hx" |
| #define DEV_MAC "aa:aa:aa:aa:aa:%02hx" |
| |
| static void initialize_netdevices(void) |
| { |
| unsigned i; |
| const char* devtypes[] = {"ip6gretap", "bridge", "vcan", "bond", "veth"}; |
| const char* devnames[] = {"lo", "sit0", "bridge0", "vcan0", |
| "tunl0", "gre0", "gretap0", "ip_vti0", |
| "ip6_vti0", "ip6tnl0", "ip6gre0", "ip6gretap0", |
| "erspan0", "bond0", "veth0", "veth1"}; |
| |
| for (i = 0; i < sizeof(devtypes) / (sizeof(devtypes[0])); i++) |
| execute_command(0, "ip link add dev %s0 type %s", devtypes[i], devtypes[i]); |
| execute_command(0, "ip link add dev veth1 type veth"); |
| for (i = 0; i < sizeof(devnames) / (sizeof(devnames[0])); i++) { |
| char addr[32]; |
| snprintf_check(addr, sizeof(addr), DEV_IPV4, i + 10); |
| execute_command(0, "ip -4 addr add %s/24 dev %s", addr, devnames[i]); |
| snprintf_check(addr, sizeof(addr), DEV_IPV6, i + 10); |
| execute_command(0, "ip -6 addr add %s/120 dev %s", addr, devnames[i]); |
| snprintf_check(addr, sizeof(addr), DEV_MAC, i + 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]); |
| } |
| } |
| |
| #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); |
| } |
| |
| 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 = 128 << 20; |
| setrlimit(RLIMIT_AS, &rlim); |
| rlim.rlim_cur = rlim.rlim_max = 8 << 20; |
| setrlimit(RLIMIT_MEMLOCK, &rlim); |
| rlim.rlim_cur = rlim.rlim_max = 1 << 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); |
| |
| #define CLONE_NEWCGROUP 0x02000000 |
| |
| if (unshare(CLONE_NEWNS)) { |
| } |
| if (unshare(CLONE_NEWIPC)) { |
| } |
| if (unshare(CLONE_NEWCGROUP)) { |
| } |
| if (unshare(CLONE_NEWUTS)) { |
| } |
| if (unshare(CLONE_SYSVSEM)) { |
| } |
| } |
| |
| 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) { |
| close(fd); |
| return false; |
| } |
| close(fd); |
| return true; |
| } |
| |
| static int real_uid; |
| static int real_gid; |
| __attribute__((aligned(64 << 10))) static char sandbox_stack[1 << 20]; |
| |
| static int namespace_sandbox_proc(void* arg) |
| { |
| sandbox_common(); |
| |
| write_file("/proc/self/setgroups", "deny"); |
| if (!write_file("/proc/self/uid_map", "0 %d 1\n", real_uid)) |
| fail("write of /proc/self/uid_map failed"); |
| if (!write_file("/proc/self/gid_map", "0 %d 1\n", real_gid)) |
| fail("write of /proc/self/gid_map failed"); |
| |
| if (unshare(CLONE_NEWNET)) |
| fail("unshare(CLONE_NEWNET)"); |
| initialize_tun(); |
| initialize_netdevices(); |
| |
| if (mkdir("./syz-tmp", 0777)) |
| fail("mkdir(syz-tmp) failed"); |
| if (mount("", "./syz-tmp", "tmpfs", 0, NULL)) |
| fail("mount(tmpfs) failed"); |
| if (mkdir("./syz-tmp/newroot", 0777)) |
| fail("mkdir failed"); |
| if (mkdir("./syz-tmp/newroot/dev", 0700)) |
| fail("mkdir failed"); |
| unsigned mount_flags = MS_BIND | MS_REC | MS_PRIVATE; |
| if (mount("/dev", "./syz-tmp/newroot/dev", NULL, mount_flags, NULL)) |
| fail("mount(dev) failed"); |
| if (mkdir("./syz-tmp/newroot/proc", 0700)) |
| fail("mkdir failed"); |
| if (mount(NULL, "./syz-tmp/newroot/proc", "proc", 0, NULL)) |
| fail("mount(proc) failed"); |
| if (mkdir("./syz-tmp/newroot/selinux", 0700)) |
| fail("mkdir failed"); |
| const char* selinux_path = "./syz-tmp/newroot/selinux"; |
| if (mount("/selinux", selinux_path, NULL, mount_flags, NULL)) { |
| if (errno != ENOENT) |
| fail("mount(/selinux) failed"); |
| if (mount("/sys/fs/selinux", selinux_path, NULL, mount_flags, NULL) && |
| errno != ENOENT) |
| fail("mount(/sys/fs/selinux) failed"); |
| } |
| if (mkdir("./syz-tmp/pivot", 0777)) |
| fail("mkdir failed"); |
| if (syscall(SYS_pivot_root, "./syz-tmp", "./syz-tmp/pivot")) { |
| if (chdir("./syz-tmp")) |
| fail("chdir failed"); |
| } else { |
| if (chdir("/")) |
| fail("chdir failed"); |
| if (umount2("./pivot", MNT_DETACH)) |
| fail("umount failed"); |
| } |
| if (chroot("./newroot")) |
| fail("chroot failed"); |
| if (chdir("/")) |
| fail("chdir failed"); |
| |
| 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)) |
| fail("capget failed"); |
| cap_data[0].effective &= ~(1 << CAP_SYS_PTRACE); |
| cap_data[0].permitted &= ~(1 << CAP_SYS_PTRACE); |
| cap_data[0].inheritable &= ~(1 << CAP_SYS_PTRACE); |
| if (syscall(SYS_capset, &cap_hdr, &cap_data)) |
| fail("capset failed"); |
| |
| loop(); |
| doexit(1); |
| } |
| |
| static int do_sandbox_namespace(void) |
| { |
| int pid; |
| |
| real_uid = getuid(); |
| real_gid = getgid(); |
| mprotect(sandbox_stack, 4096, PROT_NONE); |
| pid = |
| clone(namespace_sandbox_proc, &sandbox_stack[sizeof(sandbox_stack) - 64], |
| CLONE_NEWUSER | CLONE_NEWPID, 0); |
| if (pid < 0) |
| fail("sandbox clone failed"); |
| return pid; |
| } |
| |
| uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff}; |
| void loop() |
| { |
| long res; |
| res = syscall(__NR_socket, 0xa, 2, 0); |
| if (res != -1) |
| r[0] = res; |
| *(uint16_t*)0x20000000 = 0xa; |
| *(uint16_t*)0x20000002 = htobe16(0x4e20); |
| *(uint32_t*)0x20000004 = 0; |
| *(uint8_t*)0x20000008 = 0; |
| *(uint8_t*)0x20000009 = 0; |
| *(uint8_t*)0x2000000a = 0; |
| *(uint8_t*)0x2000000b = 0; |
| *(uint8_t*)0x2000000c = 0; |
| *(uint8_t*)0x2000000d = 0; |
| *(uint8_t*)0x2000000e = 0; |
| *(uint8_t*)0x2000000f = 0; |
| *(uint8_t*)0x20000010 = 0; |
| *(uint8_t*)0x20000011 = 0; |
| *(uint8_t*)0x20000012 = -1; |
| *(uint8_t*)0x20000013 = -1; |
| *(uint32_t*)0x20000014 = htobe32(0x7f000001); |
| *(uint32_t*)0x20000018 = 5; |
| syscall(__NR_connect, r[0], 0x20000000, 0x1c); |
| *(uint16_t*)0x20000040 = 0xa; |
| *(uint16_t*)0x20000042 = htobe16(0x4e24); |
| *(uint32_t*)0x20000044 = 0xda23; |
| *(uint64_t*)0x20000048 = htobe64(0); |
| *(uint64_t*)0x20000050 = htobe64(1); |
| *(uint32_t*)0x20000058 = 4; |
| syscall(__NR_connect, r[0], 0x20000040, 0x1c); |
| res = syscall(__NR_socket, 0x18, 1, 1); |
| if (res != -1) |
| r[1] = res; |
| *(uint16_t*)0x205fafd2 = 0x18; |
| *(uint32_t*)0x205fafd4 = 1; |
| *(uint32_t*)0x205fafd8 = 0; |
| *(uint32_t*)0x205fafdc = r[0]; |
| *(uint16_t*)0x205fafe0 = 2; |
| *(uint16_t*)0x205fafe2 = htobe16(0x4e21); |
| *(uint32_t*)0x205fafe4 = htobe32(0xe0000002); |
| *(uint8_t*)0x205fafe8 = 0; |
| *(uint8_t*)0x205fafe9 = 0; |
| *(uint8_t*)0x205fafea = 0; |
| *(uint8_t*)0x205fafeb = 0; |
| *(uint8_t*)0x205fafec = 0; |
| *(uint8_t*)0x205fafed = 0; |
| *(uint8_t*)0x205fafee = 0; |
| *(uint8_t*)0x205fafef = 0; |
| *(uint32_t*)0x205faff0 = 4; |
| *(uint32_t*)0x205faff4 = 0; |
| *(uint32_t*)0x205faff8 = 2; |
| *(uint32_t*)0x205faffc = 0; |
| syscall(__NR_connect, r[1], 0x205fafd2, 0x2e); |
| *(uint64_t*)0x2037ffc8 = 0x20041000; |
| *(uint16_t*)0x20041000 = 0x10; |
| *(uint16_t*)0x20041002 = 0; |
| *(uint32_t*)0x20041004 = 0; |
| *(uint32_t*)0x20041008 = 2; |
| *(uint32_t*)0x2037ffd0 = 0xc; |
| *(uint64_t*)0x2037ffd8 = 0x20e6c000; |
| *(uint64_t*)0x20e6c000 = 0x20e6cff0; |
| *(uint32_t*)0x20e6cff0 = 0x10; |
| *(uint16_t*)0x20e6cff4 = 0x14; |
| *(uint16_t*)0x20e6cff6 = 0x200; |
| *(uint32_t*)0x20e6cff8 = 0; |
| *(uint32_t*)0x20e6cffc = 3; |
| *(uint64_t*)0x20e6c008 = 0x10; |
| *(uint64_t*)0x2037ffe0 = 1; |
| *(uint64_t*)0x2037ffe8 = 0; |
| *(uint64_t*)0x2037fff0 = 0; |
| *(uint32_t*)0x2037fff8 = 0x8800; |
| syscall(__NR_sendmsg, r[1], 0x2037ffc8, 0x81); |
| *(uint32_t*)0x20007000 = 0x42424242; |
| *(uint32_t*)0x20007004 = 0x42424242; |
| syz_emit_ethernet(4, 0x20007000, 0); |
| } |
| |
| int main() |
| { |
| syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0); |
| use_temporary_dir(); |
| int pid = do_sandbox_namespace(); |
| int status = 0; |
| while (waitpid(pid, &status, __WALL) != pid) { |
| } |
| return 0; |
| } |