[....] Starting enhanced syslogd: rsyslogd[ 13.117796] audit: type=1400 audit(1516156616.047:5): avc: denied { syslog } for pid=3505 comm="rsyslogd" capability=34 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=capability2 permissive=1 [?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. Starting mcstransd: [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 19.168278] audit: type=1400 audit(1516156622.097:6): avc: denied { map } for pid=3644 comm="bash" path="/bin/bash" dev="sda1" ino=1457 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 Warning: Permanently added '10.128.15.237' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program [ 40.152494] audit: type=1400 audit(1516156643.082:7): avc: denied { map } for pid=3661 comm="syzkaller479670" path="/root/syzkaller479670559" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program executing program [ 40.530345] ------------[ cut here ]------------ [ 40.535205] refcount_t: increment on 0; use-after-free. [ 40.540824] WARNING: CPU: 1 PID: 3697 at lib/refcount.c:153 refcount_inc+0x47/0x50 [ 40.548509] Kernel panic - not syncing: panic_on_warn set ... [ 40.548509] [ 40.555846] CPU: 1 PID: 3697 Comm: syzkaller479670 Not tainted 4.15.0-rc8+ #174 [ 40.563263] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 40.572588] Call Trace: [ 40.575151] dump_stack+0x194/0x257 [ 40.578756] ? arch_local_irq_restore+0x53/0x53 [ 40.583400] ? vsnprintf+0x1ed/0x1900 [ 40.587179] panic+0x1e4/0x41c [ 40.590345] ? refcount_error_report+0x214/0x214 [ 40.595074] ? show_regs_print_info+0x18/0x18 [ 40.599549] ? __warn+0x1c1/0x200 [ 40.602978] ? refcount_inc+0x47/0x50 [ 40.606749] __warn+0x1dc/0x200 [ 40.610000] ? console_unlock+0x983/0xd80 [ 40.614122] ? refcount_inc+0x47/0x50 [ 40.617897] report_bug+0x211/0x2d0 [ 40.621502] fixup_bug.part.11+0x37/0x80 [ 40.625537] do_error_trap+0x2d7/0x3e0 [ 40.629398] ? __down_trylock_console_sem+0x10d/0x1e0 [ 40.634563] ? math_error+0x400/0x400 [ 40.638337] ? vprintk_emit+0x3ea/0x590 [ 40.642295] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.647113] do_invalid_op+0x1b/0x20 [ 40.650800] invalid_op+0x22/0x40 [ 40.654227] RIP: 0010:refcount_inc+0x47/0x50 [ 40.658604] RSP: 0018:ffff8801d9077788 EFLAGS: 00010286 [ 40.663948] RAX: dffffc0000000008 RBX: ffff8801d94f48c0 RCX: ffffffff8159dade [ 40.671190] RDX: 0000000000000000 RSI: 1ffff1003b20eeac RDI: ffff8801d9077490 [ 40.678432] RBP: ffff8801d9077790 R08: 1ffff1003b20ee6e R09: 0000000000000000 [ 40.685674] R10: ffff8801d9077658 R11: 0000000000000000 R12: 0000000000000000 [ 40.692915] R13: 0000000000000000 R14: ffff8801bc2540c0 R15: ffff8801d2cb6800 [ 40.700169] ? vprintk_func+0x5e/0xc0 [ 40.703949] ? refcount_inc+0x47/0x50 [ 40.707727] l2tp_session_register+0x9cb/0xe20 [ 40.712291] ? l2tp_tunnel_get+0x690/0x690 [ 40.716497] ? pppol2tp_connect+0x11ee/0x1dd0 [ 40.720966] ? lock_downgrade+0x980/0x980 [ 40.725087] ? ipv4_mtu+0x34d/0x4c0 [ 40.728688] ? rt_cpu_seq_show+0x2c0/0x2c0 [ 40.732896] ? refcount_add+0x60/0x60 [ 40.736670] ? __lock_is_held+0xb6/0x140 [ 40.740717] pppol2tp_connect+0x134b/0x1dd0 [ 40.745023] ? pppol2tp_recv_payload_hook+0x1b0/0x1b0 [ 40.750194] ? selinux_netlbl_socket_connect+0x76/0x1b0 [ 40.755535] ? selinux_socket_connect+0x311/0x730 [ 40.760349] ? lock_downgrade+0x980/0x980 [ 40.764484] ? selinux_socket_setsockopt+0x80/0x80 [ 40.769383] ? lock_release+0xa40/0xa40 [ 40.773331] ? trace_event_raw_event_sched_switch+0x800/0x800 [ 40.779188] ? __check_object_size+0x25d/0x4f0 [ 40.783749] ? __might_sleep+0x95/0x190 [ 40.787707] ? security_socket_connect+0x89/0xb0 [ 40.792442] SYSC_connect+0x213/0x4a0 [ 40.796217] ? SYSC_bind+0x410/0x410 [ 40.799906] ? handle_mm_fault+0x410/0x8d0 [ 40.804113] ? __do_page_fault+0x32d/0xc90 [ 40.808320] ? __handle_mm_fault+0x3ce0/0x3ce0 [ 40.812871] ? vmacache_find+0x5f/0x280 [ 40.816821] ? up_read+0x1a/0x40 [ 40.820162] ? __do_page_fault+0x3d6/0xc90 [ 40.824381] SyS_connect+0x24/0x30 [ 40.827892] ? SyS_accept+0x30/0x30 [ 40.831491] do_fast_syscall_32+0x3ee/0xf9d [ 40.835790] ? do_int80_syscall_32+0x9d0/0x9d0 [ 40.840343] ? trace_hardirqs_on_thunk+0x1a/0x1c [ 40.845090] ? syscall_return_slowpath+0x2ad/0x550 [ 40.849991] ? prepare_exit_to_usermode+0x340/0x340 [ 40.854985] ? retint_user+0x18/0x18 [ 40.858679] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 40.863502] entry_SYSENTER_compat+0x54/0x63 [ 40.867881] RIP: 0023:0xf7fbac79 [ 40.871216] RSP: 002b:00000000ff9c653c EFLAGS: 00000207 ORIG_RAX: 000000000000016a [ 40.878896] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00000000205fafd2 [ 40.886137] RDX: 000000000000002e RSI: 0000000000000167 RDI: 0000000000000018 [ 40.893381] RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 [ 40.900622] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 [ 40.907863] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 40.915598] Dumping ftrace buffer: [ 40.919171] (ftrace buffer empty) [ 40.922857] Kernel Offset: disabled [ 40.926459] Rebooting in 86400 seconds..