* Re: [PATCH net] af_key: free SKBs under RCU protection
2018-09-21 17:40 ` Eric Dumazet
@ 2018-09-21 18:44 ` stranche
0 siblings, 0 replies; 10+ messages in thread
From: stranche @ 2018-09-21 18:44 UTC (permalink / raw)
To: Eric Dumazet; +Cc: netdev, steffen.klassert
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On 2018-09-21 11:40, Eric Dumazet wrote:
> On 09/21/2018 10:09 AM, stranche@codeaurora.org wrote:
>
>> I also tried reverting 7f6b9dbd5afb ("af_key: locking change") and
>> running the
>> test there and I still see the crash, so it doesn't seem to be an RCU
>> specific
>> issue.
>>
>> Is there anything else that could be causing this?
>
> What about you share your repro ?
Sure. Syzkaller reproducer source is attached.
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// autogenerated by syzkaller (http://github.com/google/syzkaller)
#define _GNU_SOURCE
#include <endian.h>
#include <sys/syscall.h>
#include <unistd.h>
#include <linux/futex.h>
#include <pthread.h>
#include <stdlib.h>
#include <errno.h>
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <time.h>
#include <sys/prctl.h>
#include <dirent.h>
#include <sys/mount.h>
#include <errno.h>
#include <sched.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <arpa/inet.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/uio.h>
#include <linux/net.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/mount.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>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <setjmp.h>
#include <signal.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);
}
static void exitf(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(kRetryStatus);
}
static __thread int skip_segv;
static __thread jmp_buf segv_env;
static void segv_handler(int sig, siginfo_t* info, void* uctx) {
uintptr_t addr = (uintptr_t) info->si_addr;
const uintptr_t prog_start = 1 << 20;
const uintptr_t prog_end = 100 << 20;
if (__atomic_load_n(&skip_segv, __ATOMIC_RELAXED) &&
(addr < prog_start || addr > prog_end)) {
_longjmp(segv_env, 1);
}
doexit(sig);
}
static void install_segv_handler() {
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(...) { __atomic_fetch_add(&skip_segv, 1, __ATOMIC_SEQ_CST); if (_setjmp(segv_env) == 0) { __VA_ARGS__; } __atomic_fetch_sub(&skip_segv, 1, __ATOMIC_SEQ_CST); }
static uint64_t current_time_ms() {
struct timespec ts;
if (clock_gettime(CLOCK_MONOTONIC, &ts)) fail("clock_gettime failed");
return (uint64_t) ts.tv_sec * 1000 + (uint64_t) ts.tv_nsec / 1000000;
}
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);
va_end(args);
rv = system(command);
if (rv) {
if (panic) fail("command '%s' failed: %d", &command[0], rv);
}
}
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", "team" };
const char* devnames[] = {
"lo", "sit0", "bridge0", "vcan0", "tunl0", "gre0", "gretap0", "ip_vti0",
"ip6_vti0", "ip6tnl0", "ip6gre0", "ip6gretap0", "erspan0", "bond0", "veth0",
"veth1", "team0", "veth0_to_bridge", "veth1_to_bridge", "veth0_to_bond",
"veth1_to_bond", "veth0_to_team", "veth1_to_team"
};
const char* devmasters[] = { "bridge", "bond", "team" };
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 type veth");
for (i = 0; i < sizeof(devmasters) / (sizeof(devmasters[0])); i++) {
execute_command(
0, "ip link add name %s_slave_0 type veth peer name veth0_to_%s",
devmasters[i], devmasters[i]);
execute_command(
0, "ip link add name %s_slave_1 type veth peer name veth1_to_%s",
devmasters[i], devmasters[i]);
execute_command(0, "ip link set %s_slave_0 master %s0", devmasters[i],
devmasters[i]);
execute_command(0, "ip link set %s_slave_1 master %s0", devmasters[i],
devmasters[i]);
execute_command(0, "ip link set veth0_to_%s up", devmasters[i]);
execute_command(0, "ip link set veth1_to_%s up", devmasters[i]);
}
execute_command(0, "ip link set bridge_slave_0 up");
execute_command(0, "ip link set bridge_slave_1 up");
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]);
}
}
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;
fail("tun: read failed with %d", rv);
}
return rv;
}
static void flush_tun() {
char data[SYZ_TUN_MAX_PACKET_SIZE];
while (read_tun(&data[0], sizeof(data)) != -1)
;
}
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;
}
static void setup_cgroups() {
if (mkdir("/syzcgroup", 0777)) {
}
if (mkdir("/syzcgroup/unified", 0777)) {
}
if (mount("none", "/syzcgroup/unified", "cgroup2", 0, NULL)) {
}
if (chmod("/syzcgroup/unified", 0777)) {
}
if (!write_file("/syzcgroup/unified/cgroup.subtree_control",
"+cpu +memory +io +pids +rdma")) {
}
if (mkdir("/syzcgroup/cpu", 0777)) {
}
if (mount("none", "/syzcgroup/cpu", "cgroup", 0,
"cpuset,cpuacct,perf_event,hugetlb")) {
}
if (!write_file("/syzcgroup/cpu/cgroup.clone_children", "1")) {
}
if (chmod("/syzcgroup/cpu", 0777)) {
}
if (mkdir("/syzcgroup/net", 0777)) {
}
if (mount("none", "/syzcgroup/net", "cgroup", 0,
"net_cls,net_prio,devices,freezer")) {
}
if (chmod("/syzcgroup/net", 0777)) {
}
}
static void setup_binfmt_misc() {
if (!write_file("/proc/sys/fs/binfmt_misc/register",
":syz0:M:0:syz0::./file0:")) {
}
if (!write_file("/proc/sys/fs/binfmt_misc/register",
":syz1:M:1:yz1::./file0:POC")) {
}
}
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 = 160 << 20;
setrlimit(RLIMIT_AS, &rlim);
rlim.rlim_cur = rlim.rlim_max = 8 << 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);
/*if (unshare(CLONE_NEWNS)) {
}
if (unshare(CLONE_NEWIPC)) {
}
if (unshare(0x02000000)) {
}
if (unshare(CLONE_NEWUTS)) {
}
if (unshare(CLONE_SYSVSEM)) {
}*/
}
static int do_sandbox_none(void) {
int pid = fork();
if (pid < 0) fail("sandbox fork failed");
if (pid) return pid;
sandbox_common();
initialize_tun();
loop();
doexit(1);
}
#define XT_TABLE_SIZE 1536
#define XT_MAX_ENTRIES 10
struct xt_counters {
uint64_t pcnt, bcnt;
};
struct ipt_getinfo {
char name[32];
unsigned int valid_hooks;
unsigned int hook_entry[5];
unsigned int underflow[5];
unsigned int num_entries;
unsigned int size;
};
struct ipt_get_entries {
char name[32];
unsigned int size;
void* entrytable[XT_TABLE_SIZE / sizeof(void*)];
};
struct ipt_replace {
char name[32];
unsigned int valid_hooks;
unsigned int num_entries;
unsigned int size;
unsigned int hook_entry[5];
unsigned int underflow[5];
unsigned int num_counters;
struct xt_counters* counters;
char entrytable[XT_TABLE_SIZE];
};
struct ipt_table_desc {
const char* name;
struct ipt_getinfo info;
struct ipt_replace replace;
};
static struct ipt_table_desc ipv4_tables[] = {
{.name = "filter" }, {.name = "nat" }, {.name = "mangle" }, {.name = "raw" },
{.name = "security" },
};
static struct ipt_table_desc ipv6_tables[] = {
{.name = "filter" }, {.name = "nat" }, {.name = "mangle" }, {.name = "raw" },
{.name = "security" },
};
#define IPT_BASE_CTL 64
#define IPT_SO_SET_REPLACE (IPT_BASE_CTL)
#define IPT_SO_GET_INFO (IPT_BASE_CTL)
#define IPT_SO_GET_ENTRIES (IPT_BASE_CTL + 1)
struct arpt_getinfo {
char name[32];
unsigned int valid_hooks;
unsigned int hook_entry[3];
unsigned int underflow[3];
unsigned int num_entries;
unsigned int size;
};
struct arpt_get_entries {
char name[32];
unsigned int size;
void* entrytable[XT_TABLE_SIZE / sizeof(void*)];
};
struct arpt_replace {
char name[32];
unsigned int valid_hooks;
unsigned int num_entries;
unsigned int size;
unsigned int hook_entry[3];
unsigned int underflow[3];
unsigned int num_counters;
struct xt_counters* counters;
char entrytable[XT_TABLE_SIZE];
};
struct arpt_table_desc {
const char* name;
struct arpt_getinfo info;
struct arpt_replace replace;
};
static struct arpt_table_desc arpt_tables[] = { {.name = "filter" }, };
#define ARPT_BASE_CTL 96
#define ARPT_SO_SET_REPLACE (ARPT_BASE_CTL)
#define ARPT_SO_GET_INFO (ARPT_BASE_CTL)
#define ARPT_SO_GET_ENTRIES (ARPT_BASE_CTL + 1)
static void checkpoint_iptables(struct ipt_table_desc* tables, int num_tables,
int family, int level) {
struct ipt_get_entries entries;
socklen_t optlen;
int fd, i;
fd = socket(family, SOCK_STREAM, IPPROTO_TCP);
if (fd == -1) {
switch (errno) {
case EAFNOSUPPORT:
case ENOPROTOOPT:
return;
}
fail("socket(%d, SOCK_STREAM, IPPROTO_TCP)", family);
}
for (i = 0; i < num_tables; i++) {
struct ipt_table_desc* table = &tables[i];
strcpy(table->info.name, table->name);
strcpy(table->replace.name, table->name);
optlen = sizeof(table->info);
if (getsockopt(fd, level, IPT_SO_GET_INFO, &table->info, &optlen)) {
switch (errno) {
case EPERM:
case ENOENT:
case ENOPROTOOPT:
continue;
}
fail("getsockopt(IPT_SO_GET_INFO)");
}
if (table->info.size > sizeof(table->replace.entrytable))
fail("table size is too large: %u", table->info.size);
if (table->info.num_entries > XT_MAX_ENTRIES)
fail("too many counters: %u", table->info.num_entries);
memset(&entries, 0, sizeof(entries));
strcpy(entries.name, table->name);
entries.size = table->info.size;
optlen = sizeof(entries) - sizeof(entries.entrytable) + table->info.size;
if (getsockopt(fd, level, IPT_SO_GET_ENTRIES, &entries, &optlen))
fail("getsockopt(IPT_SO_GET_ENTRIES)");
table->replace.valid_hooks = table->info.valid_hooks;
table->replace.num_entries = table->info.num_entries;
table->replace.size = table->info.size;
memcpy(table->replace.hook_entry, table->info.hook_entry,
sizeof(table->replace.hook_entry));
memcpy(table->replace.underflow, table->info.underflow,
sizeof(table->replace.underflow));
memcpy(table->replace.entrytable, entries.entrytable, table->info.size);
}
close(fd);
}
static void reset_iptables(struct ipt_table_desc* tables, int num_tables,
int family, int level) {
struct xt_counters counters[XT_MAX_ENTRIES];
struct ipt_get_entries entries;
struct ipt_getinfo info;
socklen_t optlen;
int fd, i;
fd = socket(family, SOCK_STREAM, IPPROTO_TCP);
if (fd == -1) {
switch (errno) {
case EAFNOSUPPORT:
case ENOPROTOOPT:
return;
}
fail("socket(%d, SOCK_STREAM, IPPROTO_TCP)", family);
}
for (i = 0; i < num_tables; i++) {
struct ipt_table_desc* table = &tables[i];
if (table->info.valid_hooks == 0) continue;
memset(&info, 0, sizeof(info));
strcpy(info.name, table->name);
optlen = sizeof(info);
if (getsockopt(fd, level, IPT_SO_GET_INFO, &info, &optlen))
fail("getsockopt(IPT_SO_GET_INFO)");
if (memcmp(&table->info, &info, sizeof(table->info)) == 0) {
memset(&entries, 0, sizeof(entries));
strcpy(entries.name, table->name);
entries.size = table->info.size;
optlen = sizeof(entries) - sizeof(entries.entrytable) + entries.size;
if (getsockopt(fd, level, IPT_SO_GET_ENTRIES, &entries, &optlen))
fail("getsockopt(IPT_SO_GET_ENTRIES)");
if (memcmp(table->replace.entrytable, entries.entrytable,
table->info.size) == 0)
continue;
}
table->replace.num_counters = info.num_entries;
table->replace.counters = counters;
optlen = sizeof(table->replace) - sizeof(table->replace.entrytable) +
table->replace.size;
if (setsockopt(fd, level, IPT_SO_SET_REPLACE, &table->replace, optlen))
fail("setsockopt(IPT_SO_SET_REPLACE)");
}
close(fd);
}
static void checkpoint_arptables(void) {
struct arpt_get_entries entries;
socklen_t optlen;
unsigned i;
int fd;
fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (fd == -1) fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)");
for (i = 0; i < sizeof(arpt_tables) / sizeof(arpt_tables[0]); i++) {
struct arpt_table_desc* table = &arpt_tables[i];
strcpy(table->info.name, table->name);
strcpy(table->replace.name, table->name);
optlen = sizeof(table->info);
if (getsockopt(fd, SOL_IP, ARPT_SO_GET_INFO, &table->info, &optlen)) {
switch (errno) {
case EPERM:
case ENOENT:
case ENOPROTOOPT:
continue;
}
fail("getsockopt(ARPT_SO_GET_INFO)");
}
if (table->info.size > sizeof(table->replace.entrytable))
fail("table size is too large: %u", table->info.size);
if (table->info.num_entries > XT_MAX_ENTRIES)
fail("too many counters: %u", table->info.num_entries);
memset(&entries, 0, sizeof(entries));
strcpy(entries.name, table->name);
entries.size = table->info.size;
optlen = sizeof(entries) - sizeof(entries.entrytable) + table->info.size;
if (getsockopt(fd, SOL_IP, ARPT_SO_GET_ENTRIES, &entries, &optlen))
fail("getsockopt(ARPT_SO_GET_ENTRIES)");
table->replace.valid_hooks = table->info.valid_hooks;
table->replace.num_entries = table->info.num_entries;
table->replace.size = table->info.size;
memcpy(table->replace.hook_entry, table->info.hook_entry,
sizeof(table->replace.hook_entry));
memcpy(table->replace.underflow, table->info.underflow,
sizeof(table->replace.underflow));
memcpy(table->replace.entrytable, entries.entrytable, table->info.size);
}
close(fd);
}
static void reset_arptables() {
struct xt_counters counters[XT_MAX_ENTRIES];
struct arpt_get_entries entries;
struct arpt_getinfo info;
socklen_t optlen;
unsigned i;
int fd;
fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (fd == -1) fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)");
for (i = 0; i < sizeof(arpt_tables) / sizeof(arpt_tables[0]); i++) {
struct arpt_table_desc* table = &arpt_tables[i];
if (table->info.valid_hooks == 0) continue;
memset(&info, 0, sizeof(info));
strcpy(info.name, table->name);
optlen = sizeof(info);
if (getsockopt(fd, SOL_IP, ARPT_SO_GET_INFO, &info, &optlen))
fail("getsockopt(ARPT_SO_GET_INFO)");
if (memcmp(&table->info, &info, sizeof(table->info)) == 0) {
memset(&entries, 0, sizeof(entries));
strcpy(entries.name, table->name);
entries.size = table->info.size;
optlen = sizeof(entries) - sizeof(entries.entrytable) + entries.size;
if (getsockopt(fd, SOL_IP, ARPT_SO_GET_ENTRIES, &entries, &optlen))
fail("getsockopt(ARPT_SO_GET_ENTRIES)");
if (memcmp(table->replace.entrytable, entries.entrytable,
table->info.size) == 0)
continue;
}
table->replace.num_counters = info.num_entries;
table->replace.counters = counters;
optlen = sizeof(table->replace) - sizeof(table->replace.entrytable) +
table->replace.size;
if (setsockopt(fd, SOL_IP, ARPT_SO_SET_REPLACE, &table->replace, optlen))
fail("setsockopt(ARPT_SO_SET_REPLACE)");
}
close(fd);
}
#include <linux/if.h>
#include <linux/netfilter_bridge/ebtables.h>
struct ebt_table_desc {
const char* name;
struct ebt_replace replace;
char entrytable[XT_TABLE_SIZE];
};
static struct ebt_table_desc ebt_tables[] = {
{.name = "filter" }, {.name = "nat" }, {.name = "broute" },
};
static void checkpoint_ebtables(void) {
socklen_t optlen;
unsigned i;
int fd;
fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (fd == -1) fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)");
for (i = 0; i < sizeof(ebt_tables) / sizeof(ebt_tables[0]); i++) {
struct ebt_table_desc* table = &ebt_tables[i];
strcpy(table->replace.name, table->name);
optlen = sizeof(table->replace);
if (getsockopt(fd, SOL_IP, EBT_SO_GET_INIT_INFO, &table->replace,
&optlen)) {
switch (errno) {
case EPERM:
case ENOENT:
case ENOPROTOOPT:
continue;
}
fail("getsockopt(EBT_SO_GET_INIT_INFO)");
}
if (table->replace.entries_size > sizeof(table->entrytable))
fail("table size is too large: %u", table->replace.entries_size);
table->replace.num_counters = 0;
table->replace.entries = table->entrytable;
optlen = sizeof(table->replace) + table->replace.entries_size;
if (getsockopt(fd, SOL_IP, EBT_SO_GET_INIT_ENTRIES, &table->replace,
&optlen))
fail("getsockopt(EBT_SO_GET_INIT_ENTRIES)");
}
close(fd);
}
static void reset_ebtables() {
struct ebt_replace replace;
char entrytable[XT_TABLE_SIZE];
socklen_t optlen;
unsigned i, j, h;
int fd;
fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (fd == -1) fail("socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)");
for (i = 0; i < sizeof(ebt_tables) / sizeof(ebt_tables[0]); i++) {
struct ebt_table_desc* table = &ebt_tables[i];
if (table->replace.valid_hooks == 0) continue;
memset(&replace, 0, sizeof(replace));
strcpy(replace.name, table->name);
optlen = sizeof(replace);
if (getsockopt(fd, SOL_IP, EBT_SO_GET_INFO, &replace, &optlen))
fail("getsockopt(EBT_SO_GET_INFO)");
replace.num_counters = 0;
table->replace.entries = 0;
for (h = 0; h < NF_BR_NUMHOOKS; h++)
table->replace.hook_entry[h] = 0;
if (memcmp(&table->replace, &replace, sizeof(table->replace)) == 0) {
memset(&entrytable, 0, sizeof(entrytable));
replace.entries = entrytable;
optlen = sizeof(replace) + replace.entries_size;
if (getsockopt(fd, SOL_IP, EBT_SO_GET_ENTRIES, &replace, &optlen))
fail("getsockopt(EBT_SO_GET_ENTRIES)");
if (memcmp(table->entrytable, entrytable, replace.entries_size) == 0)
continue;
}
for (j = 0, h = 0; h < NF_BR_NUMHOOKS; h++) {
if (table->replace.valid_hooks & (1 << h)) {
table->replace.hook_entry[h] =
(struct ebt_entries*)table->entrytable + j;
j++;
}
}
table->replace.entries = table->entrytable;
optlen = sizeof(table->replace) + table->replace.entries_size;
if (setsockopt(fd, SOL_IP, EBT_SO_SET_ENTRIES, &table->replace, optlen))
fail("setsockopt(EBT_SO_SET_ENTRIES)");
}
close(fd);
}
static void checkpoint_net_namespace(void) {
checkpoint_ebtables();
checkpoint_arptables();
checkpoint_iptables(ipv4_tables, sizeof(ipv4_tables) / sizeof(ipv4_tables[0]),
AF_INET, SOL_IP);
checkpoint_iptables(ipv6_tables, sizeof(ipv6_tables) / sizeof(ipv6_tables[0]),
AF_INET6, SOL_IPV6);
}
static void reset_net_namespace(void) {
reset_ebtables();
reset_arptables();
reset_iptables(ipv4_tables, sizeof(ipv4_tables) / sizeof(ipv4_tables[0]),
AF_INET, SOL_IP);
reset_iptables(ipv6_tables, sizeof(ipv6_tables) / sizeof(ipv6_tables[0]),
AF_INET6, SOL_IPV6);
}
static void remove_dir(const char* dir) {
DIR* dp;
struct dirent* ep;
int iter = 0;
retry:
while (umount2(dir, MNT_DETACH) == 0) {
}
dp = opendir(dir);
if (dp == NULL) {
if (errno == EMFILE) {
exitf("opendir(%s) failed due to NOFILE, exiting", dir);
}
exitf("opendir(%s) failed", dir);
}
while ((ep = readdir(dp))) {
if (strcmp(ep->d_name, ".") == 0 || strcmp(ep->d_name, "..") == 0) continue;
char filename[FILENAME_MAX];
snprintf(filename, sizeof(filename), "%s/%s", dir, ep->d_name);
struct stat st;
if (lstat(filename, &st)) exitf("lstat(%s) failed", filename);
if (S_ISDIR(st.st_mode)) {
remove_dir(filename);
continue;
}
int i;
for (i = 0;; i++) {
if (unlink(filename) == 0) break;
if (errno == EROFS) {
break;
}
if (errno != EBUSY || i > 100) exitf("unlink(%s) failed", filename);
if (umount2(filename, MNT_DETACH)) exitf("umount(%s) failed", filename);
}
}
closedir(dp);
int i;
for (i = 0;; i++) {
if (rmdir(dir) == 0) break;
if (i < 100) {
if (errno == EROFS) {
break;
}
if (errno == EBUSY) {
if (umount2(dir, MNT_DETACH)) exitf("umount(%s) failed", dir);
continue;
}
if (errno == ENOTEMPTY) {
if (iter < 100) {
iter++;
goto retry;
}
}
}
exitf("rmdir(%s) failed", dir);
}
}
static void execute_one();
extern unsigned long long procid;
static void loop() {
if(0)
checkpoint_net_namespace();
char cgroupdir[64];
snprintf(cgroupdir, sizeof(cgroupdir), "/syzcgroup/unified/syz%llu", procid);
char cgroupdir_cpu[64];
snprintf(cgroupdir_cpu, sizeof(cgroupdir_cpu), "/syzcgroup/cpu/syz%llu",
procid);
char cgroupdir_net[64];
snprintf(cgroupdir_net, sizeof(cgroupdir_net), "/syzcgroup/net/syz%llu",
procid);
if (mkdir(cgroupdir, 0777)) {
}
if (mkdir(cgroupdir_cpu, 0777)) {
}
if (mkdir(cgroupdir_net, 0777)) {
}
int pid = getpid();
char procs_file[128];
snprintf(procs_file, sizeof(procs_file), "%s/cgroup.procs", cgroupdir);
if (!write_file(procs_file, "%d", pid)) {
}
snprintf(procs_file, sizeof(procs_file), "%s/cgroup.procs", cgroupdir_cpu);
if (!write_file(procs_file, "%d", pid)) {
}
snprintf(procs_file, sizeof(procs_file), "%s/cgroup.procs", cgroupdir_net);
if (!write_file(procs_file, "%d", pid)) {
}
int iter;
for (iter = 0;; iter++) {
char cwdbuf[32];
sprintf(cwdbuf, "./%d", iter);
if (mkdir(cwdbuf, 0777)) fail("failed to mkdir");
int pid = fork();
if (pid < 0) fail("clone failed");
if (pid == 0) {
prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0);
setpgrp();
if (chdir(cwdbuf)) fail("failed to chdir");
if (symlink(cgroupdir, "./cgroup")) {
}
if (symlink(cgroupdir_cpu, "./cgroup.cpu")) {
}
if (symlink(cgroupdir_net, "./cgroup.net")) {
}
flush_tun();
execute_one();
doexit(0);
}
int status = 0;
uint64_t start = current_time_ms();
for (;;) {
int res = waitpid(-1, &status, __WALL | WNOHANG);
if (res == pid) {
break;
}
usleep(1000);
if (current_time_ms() - start < 3 * 1000) continue;
kill(-pid, SIGKILL);
kill(pid, SIGKILL);
while (waitpid(-1, &status, __WALL) != pid) {
}
break;
}
remove_dir(cwdbuf);
if(0)
reset_net_namespace();
}
}
struct thread_t {
int created, running, call;
pthread_t th;
};
static struct thread_t threads[16];
static void execute_call(int call);
static int running;
static int collide;
static void* thr(void* arg) {
struct thread_t* th = (struct thread_t*)arg;
for (;;) {
while (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE))
syscall(SYS_futex, &th->running, FUTEX_WAIT, 0, 0);
execute_call(th->call);
__atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
__atomic_store_n(&th->running, 0, __ATOMIC_RELEASE);
syscall(SYS_futex, &th->running, FUTEX_WAKE);
}
return 0;
}
static void execute(int num_calls) {
int call, thread;
running = 0;
for (call = 0; call < num_calls; call++) {
for (thread = 0; thread < sizeof(threads) / sizeof(threads[0]); thread++) {
struct thread_t* th = &threads[thread];
if (!th->created) {
th->created = 1;
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setstacksize(&attr, 128 << 10);
pthread_create(&th->th, &attr, thr, th);
}
if (!__atomic_load_n(&th->running, __ATOMIC_ACQUIRE)) {
th->call = call;
__atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
__atomic_store_n(&th->running, 1, __ATOMIC_RELEASE);
syscall(SYS_futex, &th->running, FUTEX_WAKE);
if (collide && call % 2) break;
struct timespec ts;
ts.tv_sec = 0;
ts.tv_nsec = 20 * 1000 * 1000;
syscall(SYS_futex, &th->running, FUTEX_WAIT, 1, &ts);
if (running) usleep((call == num_calls - 1) ? 10000 : 1000);
break;
}
}
}
}
#ifndef __NR_mmap
#define __NR_mmap 222
#endif
#ifndef __NR_socket
#define __NR_socket 198
#endif
#ifndef __NR_sendmsg
#define __NR_sendmsg 211
#endif
uint64_t r[1] = {0xffffffffffffffff};
unsigned long long procid;
void execute_call(int call)
{
long res; switch (call) {
case 0:
res = syscall(__NR_socket, 0xf, 3, 2);
if (res != -1)
r[0] = res;
break;
case 1:
NONFAILING(*(uint64_t*)0x20000180 = 0);
NONFAILING(*(uint32_t*)0x20000188 = 0);
NONFAILING(*(uint64_t*)0x20000190 = 0x20000340);
NONFAILING(*(uint64_t*)0x20000340 = 0x20000080);
NONFAILING(memcpy((void*)0x20000080, "\x02\x0b\x80\x01\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16));
NONFAILING(*(uint64_t*)0x20000348 = 0x10);
NONFAILING(*(uint64_t*)0x20000198 = 1);
NONFAILING(*(uint64_t*)0x200001a0 = 0);
NONFAILING(*(uint64_t*)0x200001a8 = 0);
NONFAILING(*(uint32_t*)0x200001b0 = 0);
syscall(__NR_sendmsg, r[0], 0x20000180, 0);
break;
}
}
void execute_one()
{
syscall(SYS_write, 1, "executing program\n", strlen("executing program\n"));
execute(2);
collide = 1;
execute(2);
}
int main()
{
syscall(__NR_mmap, 0x20000000, 0x1000000, 3, 0x32, -1, 0);
char *cwd = get_current_dir_name();
for (procid = 0; procid < 18; procid++) {
if (fork() == 0) {
install_segv_handler();
for (;;) {
if (chdir(cwd))
fail("failed to chdir");
use_temporary_dir();
int pid = do_sandbox_none();
int status = 0;
while (waitpid(pid, &status, __WALL) != pid) {}
}
}
}
sleep(1000000);
return 0;
}
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