git: 26c1772071f7 - main - stress2: Added a syzkaller reproducer
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Date: Mon, 18 Oct 2021 07:40:25 UTC
The branch main has been updated by pho:
URL: https://cgit.FreeBSD.org/src/commit/?id=26c1772071f70b6266fe95a2f235c7a50813732b
commit 26c1772071f70b6266fe95a2f235c7a50813732b
Author: Peter Holm <pho@FreeBSD.org>
AuthorDate: 2021-10-18 07:39:55 +0000
Commit: Peter Holm <pho@FreeBSD.org>
CommitDate: 2021-10-18 07:39:55 +0000
stress2: Added a syzkaller reproducer
---
syzkaller45.sh | 289 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 289 insertions(+)
diff --git a/syzkaller45.sh b/syzkaller45.sh
new file mode 100755
index 000000000000..6c38b96ab12b
--- /dev/null
+++ b/syzkaller45.sh
@@ -0,0 +1,289 @@
+#!/bin/sh
+
+# panic: Assertion (cnp->cn_flags & (LOCKPARENT | WANTPARENT)) == 0 failed at ../../../kern/vfs_cache.c:4790
+# cpuid = 5
+# time = 1634453452
+# KDB: stack backtrace:
+# db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe0146912830
+# vpanic() at vpanic+0x187/frame 0xfffffe0146912890
+# panic() at panic+0x43/frame 0xfffffe01469128f0
+# cache_fplookup_emptypath() at cache_fplookup_emptypath+0x1b2/frame 0xfffffe0146912930
+# cache_fplookup_noentry() at cache_fplookup_noentry+0xbc/frame 0xfffffe01469129a0
+# cache_fplookup() at cache_fplookup+0x605/frame 0xfffffe0146912a90
+# namei() at namei+0x203/frame 0xfffffe0146912b50
+# vn_open_cred() at vn_open_cred+0x12c/frame 0xfffffe0146912cb0
+# kern_openat() at kern_openat+0x285/frame 0xfffffe0146912e00
+# amd64_syscall() at amd64_syscall+0x147/frame 0xfffffe0146912f30
+# fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe0146912f30
+# --- syscall (0, FreeBSD ELF64, nosys), rip = 0x8003aeafa, rsp = 0x7fffdfffdf28, rbp = 0x7fffdfffdf70 ---
+# KDB: enter: panic
+# [ thread pid 2864 tid 100315 ]
+# Stopped at kdb_enter+0x37: movq $0,0x126f74e(%rip)
+# db> x/s version
+# version: FreeBSD 14.0-CURRENT #0 main-n250087-a7d137fcbcac: Sun Oct 17 08:46:08 CEST 2021
+# pho@mercat1.netperf.freebsd.org:/usr/src/sys/amd64/compile/PHO\012
+# db>
+
+# Fixed by 1045352f1503
+
+[ `uname -p` != "amd64" ] && exit 0
+[ `id -u ` -ne 0 ] && echo "Must be root!" && exit 1
+
+. ../default.cfg
+cat > /tmp/syzkaller45.c <<EOF
+// https://syzkaller.appspot.com/bug?id=283995ae4346041c1757f62f3322a3545d0a62a4
+// autogenerated by syzkaller (https://github.com/google/syzkaller)
+// Reported-by: syzbot+bd48ee0843206a09e6b8@syzkaller.appspotmail.com
+
+#define _GNU_SOURCE
+
+#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/syscall.h>
+#include <time.h>
+#include <unistd.h>
+
+static __thread int skip_segv;
+static __thread jmp_buf segv_env;
+
+static void segv_handler(int sig, siginfo_t* info, void* ctx __unused)
+{
+ 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 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 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;
+}
+
+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 loop(void)
+{
+ int i, call, thread;
+ int collide = 0;
+again:
+ for (call = 0; call < 3; 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 (collide && (call % 2) == 0)
+ break;
+ event_timedwait(&th->done, 50);
+ break;
+ }
+ }
+ for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++)
+ sleep_ms(1);
+ if (!collide) {
+ collide = 1;
+ goto again;
+ }
+}
+
+uint64_t r[1] = {0xffffffffffffffff};
+
+void execute_call(int call)
+{
+ intptr_t res = 0;
+ switch (call) {
+ case 0:
+ NONFAILING(memcpy((void*)0x20000480, "./file0\000", 8));
+ res = syscall(SYS_open, 0x20000480ul, 0x80400000000206ul, 0ul);
+ if (res != -1)
+ r[0] = res;
+ break;
+ case 1:
+ syscall(SYS_mmap, 0x20000000ul, 0x200000ul, 1ul, 0x12ul, r[0], 0ul);
+ break;
+ case 2:
+ syscall(SYS_ftruncate, r[0], 5ul);
+ break;
+ }
+}
+int main(void)
+{
+ syscall(SYS_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x1012ul, -1, 0ul);
+ install_segv_handler();
+ loop();
+ return 0;
+}
+EOF
+mycc -o /tmp/syzkaller45 -Wall -Wextra -O0 /tmp/syzkaller45.c -lpthread || exit 1
+
+(cd /tmp; ./syzkaller45)
+
+rm -rf /tmp/syzkaller45 /tmp/syzkaller45.c /tmp/syzkaller.* /tmp/file0
+exit 0