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|
#!/bin/sh
# Fatal trap 12: page fault while in kernel mode
# cpuid = 6; apic id = 06
# fault virtual address = 0xb8
# fault code = supervisor read data, page not present
# instruction pointer = 0x20:0xffffffff80d3c17b
# stack pointer = 0x28:0xfffffe00e49fab80
# frame pointer = 0x28:0xfffffe00e49facc0
# code segment = base 0x0, limit 0xfffff, type 0x1b
# = DPL 0, pres 1, long 1, def32 0, gran 1
# processor eflags = interrupt enabled, resume, IOPL = 0
# current process = 12 (swi1: netisr 0)
# rdi: fffff802d2d8daa0 rsi: fffffe00e49fab48 rdx: ffffffff819d5a90
# rcx: ffffffff819d5a98 r8: 00000000ffffffff r9: 0000000000000000
# rax: 0000000000000000 rbx: 0000000000000002 rbp: fffffe00e49facc0
# r10: fffff802d2d8daa0 r11: 0000000000010000 r12: 0000000000000000
# r13: fffff802d2d8da80 r14: 0000000000000060 r15: fffff802d2d8dab8
# trap number = 12
# panic: page fault
# cpuid = 6
# time = 1689053386
# KDB: stack backtrace:
# db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe00e49fa930
# vpanic() at vpanic+0x149/frame 0xfffffe00e49fa980
# panic() at panic+0x43/frame 0xfffffe00e49fa9e0
# trap_fatal() at trap_fatal+0x40c/frame 0xfffffe00e49faa40
# trap_pfault() at trap_pfault+0xae/frame 0xfffffe00e49faab0
# calltrap() at calltrap+0x8/frame 0xfffffe00e49faab0
# --- trap 0xc, rip = 0xffffffff80d3c17b, rsp = 0xfffffe00e49fab80, rbp = 0xfffffe00e49facc0 ---
# tcp_input_with_port() at tcp_input_with_port+0x70b/frame 0xfffffe00e49facc0
# tcp6_input_with_port() at tcp6_input_with_port+0x6a/frame 0xfffffe00e49facf0
# tcp6_input() at tcp6_input+0xb/frame 0xfffffe00e49fad00
# ip6_input() at ip6_input+0xc97/frame 0xfffffe00e49fade0
# swi_net() at swi_net+0x19b/frame 0xfffffe00e49fae60
# ithread_loop() at ithread_loop+0x266/frame 0xfffffe00e49faef0
# fork_exit() at fork_exit+0x82/frame 0xfffffe00e49faf30
# fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe00e49faf30
# --- trap 0, rip = 0, rsp = 0, rbp = 0 ---
# KDB: enter: panic
# [ thread pid 12 tid 100089 ]
# Stopped at kdb_enter+0x32: movq $0,0xde5053(%rip)
# db> x/s version
# version: FreeBSD 14.0-CURRENT #0 main-n264110-43ed91e00bbb1: Tue Jul 11 06:28:21 CEST 2023
# pho@mercat1.netperf.freebsd.org:/usr/src/sys/amd64/compile/PHO
# db>
uname -p | grep -Eq "amd64" || exit 0
[ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
. ../default.cfg
prog=$(basename "$0" .sh)
cat > /tmp/$prog.c <<EOF
// https://syzkaller.appspot.com/bug?id=44d933862f436b628c77db28122dbfa4e00990aa
// autogenerated by syzkaller (https://github.com/google/syzkaller)
// Reported-by: syzbot+e7d2e451f89fb444319b@syzkaller.appspotmail.com
#define _GNU_SOURCE
#include <sys/types.h>
#include <dirent.h>
#include <errno.h>
#include <pthread.h>
#include <pwd.h>
#include <setjmp.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/endian.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
static unsigned long long procid;
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 __unused)
{
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 (sig == SIGBUS)
valid = 1;
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_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; \
})
static void kill_and_wait(int pid, int* status)
{
kill(pid, SIGKILL);
while (waitpid(-1, status, 0) != pid) {
}
}
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 void use_temporary_dir(void)
{
char tmpdir_template[] = "./syzkaller.XXXXXX";
char* tmpdir = mkdtemp(tmpdir_template);
if (!tmpdir)
exit(1);
if (chmod(tmpdir, 0777))
exit(1);
if (chdir(tmpdir))
exit(1);
}
static void reset_flags(const char* filename)
{
struct stat st;
if (lstat(filename, &st))
exit(1);
st.st_flags &= ~(SF_NOUNLINK | UF_NOUNLINK | SF_IMMUTABLE | UF_IMMUTABLE |
SF_APPEND | UF_APPEND);
if (lchflags(filename, st.st_flags))
exit(1);
}
static void __attribute__((noinline)) remove_dir(const char* dir)
{
DIR* dp = opendir(dir);
if (dp == NULL) {
if (errno == EACCES) {
if (rmdir(dir))
exit(1);
return;
}
exit(1);
}
struct dirent* ep = 0;
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))
exit(1);
if (S_ISDIR(st.st_mode)) {
remove_dir(filename);
continue;
}
if (unlink(filename)) {
if (errno == EPERM) {
reset_flags(filename);
reset_flags(dir);
if (unlink(filename) == 0)
continue;
}
exit(1);
}
}
closedir(dp);
while (rmdir(dir)) {
if (errno == EPERM) {
reset_flags(dir);
if (rmdir(dir) == 0)
break;
}
exit(1);
}
}
static void thread_start(void* (*fn)(void*), void* arg)
{
pthread_t th;
pthread_attr_t attr;
pthread_attr_init(&attr);
pthread_attr_setstacksize(&attr, 128 << 10);
int i = 0;
for (; i < 100; i++) {
if (pthread_create(&th, &attr, fn, arg) == 0) {
pthread_attr_destroy(&attr);
return;
}
if (errno == EAGAIN) {
usleep(50);
continue;
}
break;
}
exit(1);
}
typedef struct {
pthread_mutex_t mu;
pthread_cond_t cv;
int state;
} event_t;
static void event_init(event_t* ev)
{
if (pthread_mutex_init(&ev->mu, 0))
exit(1);
if (pthread_cond_init(&ev->cv, 0))
exit(1);
ev->state = 0;
}
static void event_reset(event_t* ev)
{
ev->state = 0;
}
static void event_set(event_t* ev)
{
pthread_mutex_lock(&ev->mu);
if (ev->state)
exit(1);
ev->state = 1;
pthread_mutex_unlock(&ev->mu);
pthread_cond_broadcast(&ev->cv);
}
static void event_wait(event_t* ev)
{
pthread_mutex_lock(&ev->mu);
while (!ev->state)
pthread_cond_wait(&ev->cv, &ev->mu);
pthread_mutex_unlock(&ev->mu);
}
static int event_isset(event_t* ev)
{
pthread_mutex_lock(&ev->mu);
int res = ev->state;
pthread_mutex_unlock(&ev->mu);
return res;
}
static int event_timedwait(event_t* ev, uint64_t timeout)
{
uint64_t start = current_time_ms();
uint64_t now = start;
pthread_mutex_lock(&ev->mu);
for (;;) {
if (ev->state)
break;
uint64_t remain = timeout - (now - start);
struct timespec ts;
ts.tv_sec = remain / 1000;
ts.tv_nsec = (remain % 1000) * 1000 * 1000;
pthread_cond_timedwait(&ev->cv, &ev->mu, &ts);
now = current_time_ms();
if (now - start > timeout)
break;
}
int res = ev->state;
pthread_mutex_unlock(&ev->mu);
return res;
}
static void sandbox_common()
{
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);
rlim.rlim_cur = rlim.rlim_max = 256;
setrlimit(RLIMIT_NOFILE, &rlim);
}
static void loop();
static int do_sandbox_none(void)
{
sandbox_common();
loop();
return 0;
}
struct thread_t {
int created, call;
event_t ready, done;
};
static struct thread_t threads[16];
static void execute_call(int call);
static int running;
static void* thr(void* arg)
{
struct thread_t* th = (struct thread_t*)arg;
for (;;) {
event_wait(&th->ready);
event_reset(&th->ready);
execute_call(th->call);
__atomic_fetch_sub(&running, 1, __ATOMIC_RELAXED);
event_set(&th->done);
}
return 0;
}
static void execute_one(void)
{
int i, call, thread;
for (call = 0; call < 7; call++) {
for (thread = 0; thread < (int)(sizeof(threads) / sizeof(threads[0]));
thread++) {
struct thread_t* th = &threads[thread];
if (!th->created) {
th->created = 1;
event_init(&th->ready);
event_init(&th->done);
event_set(&th->done);
thread_start(thr, th);
}
if (!event_isset(&th->done))
continue;
event_reset(&th->done);
th->call = call;
__atomic_fetch_add(&running, 1, __ATOMIC_RELAXED);
event_set(&th->ready);
if (call == 3)
break;
event_timedwait(&th->done, 50);
break;
}
}
for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++)
sleep_ms(1);
}
static void execute_one(void);
#define WAIT_FLAGS 0
static void loop(void)
{
int iter = 0;
for (;; iter++) {
char cwdbuf[32];
sprintf(cwdbuf, "./%d", iter);
if (mkdir(cwdbuf, 0777))
exit(1);
int pid = fork();
if (pid < 0)
exit(1);
if (pid == 0) {
if (chdir(cwdbuf))
exit(1);
execute_one();
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 < 5000)
continue;
kill_and_wait(pid, &status);
break;
}
remove_dir(cwdbuf);
}
}
uint64_t r[2] = {0xffffffffffffffff, 0xffffffffffffffff};
void execute_call(int call)
{
intptr_t res = 0;
switch (call) {
case 0:
res = syscall(SYS_socket, 0x1cul, 1ul, 0);
if (res != -1)
r[0] = res;
break;
case 1:
NONFAILING(*(uint32_t*)0x20000080 = 9);
syscall(SYS_setsockopt, r[0], 0xffff, 0x10000, 0x20000080ul, 4ul);
break;
case 2:
NONFAILING(*(uint8_t*)0x200000c0 = 0x1c);
NONFAILING(*(uint8_t*)0x200000c1 = 0x1c);
NONFAILING(*(uint16_t*)0x200000c2 = htobe16(0x4e20 + procid * 4));
NONFAILING(*(uint32_t*)0x200000c4 = 0);
NONFAILING(memset((void*)0x200000c8, 0, 16));
NONFAILING(*(uint32_t*)0x200000d8 = 0);
syscall(SYS_bind, r[0], 0x200000c0ul, 0x1cul);
break;
case 3:
NONFAILING(*(uint32_t*)0x20000080 = 9);
syscall(SYS_setsockopt, r[0], 0xffff, 0x10000, 0x20000080ul, 4ul);
break;
case 4:
NONFAILING(*(uint32_t*)0x20000040 = 0x72);
NONFAILING(*(uint8_t*)0x20000048 = 0x10);
NONFAILING(*(uint8_t*)0x20000049 = 2);
NONFAILING(*(uint16_t*)0x2000004a = htobe16(0x4e21 + procid * 4));
NONFAILING(*(uint32_t*)0x2000004c = htobe32(0x7f000001));
NONFAILING(memset((void*)0x20000050, 0, 8));
NONFAILING(memset((void*)0x20000058, 0, 112));
syscall(SYS_setsockopt, r[0], 0, 0x51, 0x20000040ul, 0x88ul);
break;
case 5:
res = syscall(SYS_socket, 0x1cul, 1ul, 0);
if (res != -1)
r[1] = res;
break;
case 6:
NONFAILING(*(uint8_t*)0x20000140 = 0x1c);
NONFAILING(*(uint8_t*)0x20000141 = 0x1c);
NONFAILING(*(uint16_t*)0x20000142 = htobe16(0x4e20 + procid * 4));
NONFAILING(*(uint32_t*)0x20000144 = 0);
NONFAILING(memset((void*)0x20000148, 0, 16));
NONFAILING(*(uint32_t*)0x20000158 = 0);
syscall(SYS_connect, r[1], 0x20000140ul, 0x1cul);
break;
}
}
int main(void)
{
syscall(SYS_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x1012ul, -1, 0ul);
install_segv_handler();
for (procid = 0; procid < 4; procid++) {
if (fork() == 0) {
use_temporary_dir();
do_sandbox_none();
}
}
sleep(1000000);
return 0;
}
EOF
mycc -o /tmp/$prog -Wall -Wextra -O0 /tmp/$prog.c -lpthread || exit 1
(cd ../testcases/swap; ./swap -t 2m -i 10 -l 100 > /dev/null 2>&1) &
(cd /tmp; timeout 2m ./$prog)
wait
rm -rf /tmp/$prog /tmp/$prog.c /tmp/syzkaller.*
exit 0
|