#!/bin/sh # Fatal trap 12: page fault while in kernel mode # cpuid = 10; apic id = 0a # fault virtual address = 0x0 # fault code = supervisor read data, page not present # instruction pointer = 0x20:0xffffffff80e04f35 # stack pointer = 0x28:0xfffffe014fd0fbc0 # frame pointer = 0x28:0xfffffe014fd0fc00 # 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 = 13332 (repro77) # trap number = 12 # panic: page fault # cpuid = 10 # time = 1640585179 # KDB: stack backtrace: # db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe014fd0f980 # vpanic() at vpanic+0x17f/frame 0xfffffe014fd0f9d0 # panic() at panic+0x43/frame 0xfffffe014fd0fa30 # trap_fatal() at trap_fatal+0x385/frame 0xfffffe014fd0fa90 # trap_pfault() at trap_pfault+0xab/frame 0xfffffe014fd0faf0 # calltrap() at calltrap+0x8/frame 0xfffffe014fd0faf0 # --- trap 0xc, rip = 0xffffffff80e04f35, rsp = 0xfffffe014fd0fbc0, rbp = 0xfffffe014fd0fc00 --- # tcp_usr_rcvd() at tcp_usr_rcvd+0x65/frame 0xfffffe014fd0fc00 # soreceive_generic() at soreceive_generic+0xe44/frame 0xfffffe014fd0fcc0 # soreceive() at soreceive+0x4b/frame 0xfffffe014fd0fce0 # kern_recvit() at kern_recvit+0x1ba/frame 0xfffffe014fd0fd90 # sys_recvmsg() at sys_recvmsg+0x6f/frame 0xfffffe014fd0fe00 # amd64_syscall() at amd64_syscall+0x145/frame 0xfffffe014fd0ff30 # fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe014fd0ff30 # --- syscall (0, FreeBSD ELF64, nosys), rip = 0x8020e328a, rsp = 0x22f48, rbp = 0x22f70 --- # KDB: enter: panic # [ thread pid 13332 tid 103311 ] # Stopped at kdb_enter+0x37: movq $0,0x128720e(%rip) # db> x/s version # version: FreeBSD 14.0-CURRENT #0 ufs-n251956-c3008785b91: Mon Dec 27 06:11:30 CET 2021 # pho@mercat1.netperf.freebsd.org:/var/tmp/deviant3/sys/amd64/compile/PHO # db> . ../default.cfg [ `id -u` -ne 0 ] && echo "Must be root!" && exit 1 cat > /tmp/syzkaller49.c < #include #include #include #include #include #include #include #include #include #include #include #include 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; for (call = 0; call < 6; 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); event_timedwait(&th->done, 50); break; } } for (i = 0; i < 100 && __atomic_load_n(&running, __ATOMIC_RELAXED); i++) sleep_ms(1); } uint64_t r[1] = {0xffffffffffffffff}; void execute_call(int call) { intptr_t res = 0; switch (call) { case 0: res = syscall(SYS_socket, 2ul, 1ul, 0); if (res != -1) r[0] = res; break; case 1: *(uint8_t*)0x20000140 = 0x10; *(uint8_t*)0x20000141 = 2; *(uint16_t*)0x20000142 = htobe16(0x4e23); *(uint32_t*)0x20000144 = htobe32(0x7f000001); memset((void*)0x20000148, 0, 8); syscall(SYS_bind, r[0], 0x20000140ul, 0x10ul); break; case 2: *(uint8_t*)0x20000080 = 0x10; *(uint8_t*)0x20000081 = 2; *(uint16_t*)0x20000082 = htobe16(0x4e23); *(uint32_t*)0x20000084 = htobe32(0x7f000001); memset((void*)0x20000088, 0, 8); syscall(SYS_sendto, r[0], 0ul, 0ul, 0ul, 0x20000080ul, 0x10ul); break; case 3: memset((void*)0x20000100, 69, 1); syscall(SYS_sendto, r[0], 0x20000100ul, 0xfda4ul, 0ul, 0ul, 0ul); break; case 4: *(uint64_t*)0x200003c0 = 0; *(uint32_t*)0x200003c8 = 0; *(uint64_t*)0x200003d0 = 0x20000340; *(uint64_t*)0x20000340 = 0x20000680; *(uint64_t*)0x20000348 = 0x19000; *(uint64_t*)0x200003d8 = 1; *(uint64_t*)0x200003e0 = 0; *(uint64_t*)0x200003e8 = 0; *(uint32_t*)0x200003f0 = 0; syscall(SYS_recvmsg, r[0], 0x200003c0ul, 0x40ul); break; case 5: syscall(SYS_shutdown, r[0], 1ul); break; } } int main(void) { syscall(SYS_mmap, 0x20000000ul, 0x1000000ul, 7ul, 0x1012ul, -1, 0ul); loop(); return 0; } EOF set -e mount | grep "on $mntpoint " | grep -q /dev/md && umount -f $mntpoint [ -c /dev/md$mdstart ] && mdconfig -d -u $mdstart mdconfig -a -t swap -s 5g -u $mdstart newfs $newfs_flags -n md$mdstart > /dev/null mount /dev/md$mdstart $mntpoint set +e mkdir $mntpoint/work mycc -o $mntpoint/work/syzkaller49 -Wall -Wextra -O0 /tmp/syzkaller49.c -lpthread || exit 1 start=`date +%s` while [ $((`date +%s` - start)) -lt 120 ]; do (cd $mntpoint/work; ./syzkaller49) done for i in `jot 6`; do mount | grep -q "on $mntpoint " || break umount $mntpoint && break || sleep 10 [ $i -eq 6 ] && { echo FATAL; fstat -mf $mntpoint; exit 1; } done mdconfig -d -u $mdstart rm -rf /tmp/syzkaller49.c exit 0