[....] Starting periodic command[ 39.223436][ T26] audit: type=1800 audit(1555810642.923:32): pid=7710 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="ssh" dev="sda1" ino=2417 res=0 scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting file context maintaining daemon: restorecond[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 39.987340][ T26] audit: type=1800 audit(1555810643.683:33): pid=7710 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:kernel_t:s0 op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 Debian GNU/Linux 7 syzkaller ttyS0 syzkaller login: [ 43.193699][ T26] kauditd_printk_skb: 1 callbacks suppressed [ 43.193713][ T26] audit: type=1400 audit(1555810646.893:35): avc: denied { map } for pid=7886 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 '10.128.0.192' (ECDSA) to the list of known hosts. executing program [ 49.614637][ T26] audit: type=1400 audit(1555810653.313:36): avc: denied { map } for pid=7898 comm="syz-executor646" path="/root/syz-executor646566671" dev="sda1" ino=15903 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 [ 52.087485][ T7941] ------------[ cut here ]------------ [ 52.093107][ T7941] percpu_ref_kill_and_confirm called more than once on io_ring_ctx_ref_free! [ 52.093338][ T7941] WARNING: CPU: 0 PID: 7941 at lib/percpu-refcount.c:335 percpu_ref_kill_and_confirm+0x341/0x3b0 [ 52.112563][ T7941] Kernel panic - not syncing: panic_on_warn set ... [ 52.119143][ T7941] CPU: 0 PID: 7941 Comm: syz-executor646 Not tainted 5.1.0-rc5+ #77 [ 52.127088][ T7941] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 52.137113][ T7941] Call Trace: [ 52.140387][ T7941] dump_stack+0x172/0x1f0 [ 52.144706][ T7941] ? percpu_ref_kill_and_confirm+0x340/0x3b0 [ 52.150661][ T7941] panic+0x2cb/0x65c [ 52.154531][ T7941] ? __warn_printk+0xf3/0xf3 [ 52.159101][ T7941] ? percpu_ref_kill_and_confirm+0x341/0x3b0 [ 52.165054][ T7941] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 52.171296][ T7941] ? __warn.cold+0x5/0x45 [ 52.175618][ T7941] ? __warn+0xe8/0x1d0 [ 52.179665][ T7941] ? percpu_ref_kill_and_confirm+0x341/0x3b0 [ 52.185620][ T7941] __warn.cold+0x20/0x45 [ 52.189845][ T7941] ? vprintk_emit+0x1ce/0x6d0 [ 52.194500][ T7941] ? percpu_ref_kill_and_confirm+0x341/0x3b0 [ 52.200457][ T7941] report_bug+0x263/0x2b0 [ 52.204767][ T7941] do_error_trap+0x11b/0x200 [ 52.209336][ T7941] do_invalid_op+0x37/0x50 [ 52.213736][ T7941] ? percpu_ref_kill_and_confirm+0x341/0x3b0 [ 52.219700][ T7941] invalid_op+0x14/0x20 [ 52.223832][ T7941] RIP: 0010:percpu_ref_kill_and_confirm+0x341/0x3b0 [ 52.230499][ T7941] Code: 42 e0 2a 06 01 48 89 fa 48 c1 ea 03 80 3c 02 00 75 76 49 8b 54 24 10 48 c7 c6 a0 71 a1 87 48 c7 c7 40 71 a1 87 e8 ad 92 13 fe <0f> 0b 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 80 3c 02 [ 52.250091][ T7941] RSP: 0018:ffff88808c6a7cf0 EFLAGS: 00010082 [ 52.256144][ T7941] RAX: 0000000000000000 RBX: 0000607f5142f86b RCX: 0000000000000000 [ 52.264090][ T7941] RDX: 0000000000000000 RSI: ffffffff815afcf6 RDI: ffffed10118d4f90 [ 52.272036][ T7941] RBP: ffff88808c6a7d20 R08: ffff8880a7e84680 R09: fffffbfff1133639 [ 52.279980][ T7941] R10: fffffbfff1133638 R11: ffffffff8899b1c3 R12: ffff8880a7c7a9c0 [ 52.287923][ T7941] R13: ffff8880a7c7a9c8 R14: 0000000000000286 R15: 0000000000000000 [ 52.295886][ T7941] ? vprintk_func+0x86/0x189 [ 52.300473][ T7941] __io_uring_register+0xa7/0x1fe0 [ 52.305559][ T7941] ? __mutex_lock+0x3cd/0x1310 [ 52.310306][ T7941] ? __x64_sys_io_uring_register+0x182/0x1f0 [ 52.316258][ T7941] ? mutex_trylock+0x1e0/0x1e0 [ 52.321002][ T7941] ? io_sq_wq_submit_work+0x10f0/0x10f0 [ 52.326522][ T7941] ? kasan_check_write+0x14/0x20 [ 52.331438][ T7941] __x64_sys_io_uring_register+0x193/0x1f0 [ 52.337221][ T7941] do_syscall_64+0x103/0x610 [ 52.341788][ T7941] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 52.347653][ T7941] RIP: 0033:0x4467c9 [ 52.351521][ T7941] Code: e8 5c b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 0b 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 52.371096][ T7941] RSP: 002b:00007fb1ddbbcdb8 EFLAGS: 00000246 ORIG_RAX: 00000000000001ab [ 52.379490][ T7941] RAX: ffffffffffffffda RBX: 00000000006dbc38 RCX: 00000000004467c9 [ 52.387436][ T7941] RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000003 [ 52.395382][ T7941] RBP: 00000000006dbc30 R08: 00007fb1ddbbd700 R09: 0000000000000000 [ 52.403341][ T7941] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc3c [ 52.411288][ T7941] R13: 00007fffb51a643f R14: 00007fb1ddbbd9c0 R15: 20c49ba5e353f7cf [ 52.420435][ T7941] Kernel Offset: disabled [ 52.424847][ T7941] Rebooting in 86400 seconds..