[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 83.641441][ T27] audit: type=1800 audit(1580194034.953:25): pid=9534 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 83.661333][ T27] audit: type=1800 audit(1580194034.953:26): pid=9534 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 83.710271][ T27] audit: type=1800 audit(1580194034.963:27): pid=9534 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="restorecond" dev="sda1" ino=2436 res=0 [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.10.45' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 94.074364][ T157] kasan: CONFIG_KASAN_INLINE enabled [ 94.074451][ T157] kasan: GPF could be caused by NULL-ptr deref or user memory access [ 94.074518][ T157] general protection fault: 0000 [#1] PREEMPT SMP KASAN [ 94.074531][ T157] CPU: 0 PID: 157 Comm: kworker/u4:3 Not tainted 5.5.0-syzkaller #0 [ 94.074538][ T157] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 94.074554][ T157] Workqueue: events_unbound flush_to_ldisc [ 94.074573][ T157] RIP: 0010:do_con_write.part.0+0xa01/0x1ef0 [ 94.074585][ T157] Code: 7e fe ff ff 45 01 ef e8 bd 70 87 fd 48 8b 85 c8 fe ff ff 80 38 00 0f 85 71 12 00 00 49 8b 9e a0 03 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 14 20 48 89 d8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 [ 94.074592][ T157] RSP: 0018:ffffc900015b77c8 EFLAGS: 00010203 [ 94.074601][ T157] RAX: 0000000020000001 RBX: 000000010000000e RCX: ffffffff83ed8650 [ 94.074608][ T157] RDX: 0000000000000000 RSI: ffffffff83ed86a3 RDI: 0000000000000003 [ 94.074616][ T157] RBP: ffffc900015b7958 R08: ffff8880a9350100 R09: ffff8880a9350990 [ 94.074623][ T157] R10: fffffbfff14f6710 R11: ffffffff8a7b3887 R12: dffffc0000000000 [ 94.074630][ T157] R13: 0000000000000000 R14: ffff88809ee55000 R15: 000000000000075e [ 94.074640][ T157] FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 [ 94.074647][ T157] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 94.074655][ T157] CR2: 00007fed4ad2b000 CR3: 00000000923e4000 CR4: 00000000001406f0 [ 94.074665][ T157] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 94.074671][ T157] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 94.074675][ T157] Call Trace: [ 94.074700][ T157] ? do_con_trol+0x61b0/0x61b0 [ 94.074718][ T157] ? n_tty_receive_buf_common+0xc3a/0x2b70 [ 94.074736][ T157] ? do_con_write.part.0+0x1ef0/0x1ef0 [ 94.074750][ T157] con_put_char+0xfa/0x110 [ 94.074765][ T157] ? do_con_write.part.0+0x1ef0/0x1ef0 [ 94.074779][ T157] ? n_tty_receive_buf_common+0xc0e/0x2b70 [ 94.074793][ T157] ? mutex_trylock+0x2d0/0x2d0 [ 94.074809][ T157] tty_put_char+0xc5/0x160 [ 94.074821][ T157] ? tty_hung_up_p+0x70/0x70 [ 94.074835][ T157] ? wait_for_completion+0x440/0x440 [ 94.074852][ T157] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 94.074867][ T157] ? con_write_room+0x5d/0x70 [ 94.074882][ T157] __process_echoes+0x5c8/0xa40 [ 94.074901][ T157] n_tty_receive_buf_common+0xc77/0x2b70 [ 94.074928][ T157] n_tty_receive_buf2+0x34/0x40 [ 94.074940][ T157] tty_ldisc_receive_buf+0xad/0x1c0 [ 94.074952][ T157] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 94.074966][ T157] ? n_tty_receive_buf_common+0x2b70/0x2b70 [ 94.074980][ T157] tty_port_default_receive_buf+0x7d/0xb0 [ 94.074992][ T157] flush_to_ldisc+0x222/0x390 [ 94.075009][ T157] process_one_work+0x9af/0x1740 [ 94.075026][ T157] ? pwq_dec_nr_in_flight+0x320/0x320 [ 94.075037][ T157] ? lock_acquire+0x190/0x410 [ 94.075055][ T157] worker_thread+0x98/0xe40 [ 94.075074][ T157] kthread+0x361/0x430 [ 94.075091][ T157] ? process_one_work+0x1740/0x1740 [ 94.075103][ T157] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 94.075118][ T157] ret_from_fork+0x24/0x30 [ 94.075130][ T157] Modules linked in: [ 94.075146][ T157] ---[ end trace 69feb6828ad5cbf6 ]--- [ 94.075161][ T157] RIP: 0010:do_con_write.part.0+0xa01/0x1ef0 [ 94.075172][ T157] Code: 7e fe ff ff 45 01 ef e8 bd 70 87 fd 48 8b 85 c8 fe ff ff 80 38 00 0f 85 71 12 00 00 49 8b 9e a0 03 00 00 48 89 d8 48 c1 e8 03 <42> 0f b6 14 20 48 89 d8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 [ 94.075177][ T157] RSP: 0018:ffffc900015b77c8 EFLAGS: 00010203 [ 94.075185][ T157] RAX: 0000000020000001 RBX: 000000010000000e RCX: ffffffff83ed8650 [ 94.075190][ T157] RDX: 0000000000000000 RSI: ffffffff83ed86a3 RDI: 0000000000000003 [ 94.075197][ T157] RBP: ffffc900015b7958 R08: ffff8880a9350100 R09: ffff8880a9350990 [ 94.075204][ T157] R10: fffffbfff14f6710 R11: ffffffff8a7b3887 R12: dffffc0000000000 [ 94.075208][ T157] R13: 0000000000000000 R14: ffff88809ee55000 R15: 000000000000075e [ 94.075214][ T157] FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 [ 94.075219][ T157] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 94.075223][ T157] CR2: 00007fed4ad2b000 CR3: 00000000923e4000 CR4: 00000000001406f0 [ 94.075230][ T157] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 94.075234][ T157] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 94.075238][ T157] Kernel panic - not syncing: Fatal exception [ 94.076722][ T157] Kernel Offset: disabled