[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 68.844284][ T26] audit: type=1800 audit(1580018159.251:25): pid=9603 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 68.875584][ T26] audit: type=1800 audit(1580018159.261:26): pid=9603 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 68.902350][ T26] audit: type=1800 audit(1580018159.261:27): pid=9603 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 '10.128.1.27' (ECDSA) to the list of known hosts. executing program executing program executing program executing program executing program executing program syzkaller login: [ 86.399138][ T426] kasan: CONFIG_KASAN_INLINE enabled [ 86.399162][ T426] kasan: GPF could be caused by NULL-ptr deref or user memory access [ 86.399180][ T426] general protection fault: 0000 [#1] PREEMPT SMP KASAN [ 86.399193][ T426] CPU: 1 PID: 426 Comm: kworker/u4:6 Not tainted 5.5.0-rc7-syzkaller #0 [ 86.399200][ T426] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 86.399216][ T426] Workqueue: events_unbound flush_to_ldisc [ 86.399237][ T426] RIP: 0010:do_con_write.part.0+0xa01/0x1ef0 [ 86.399250][ T426] Code: 7e fe ff ff 45 01 ef e8 fd 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 [ 86.399262][ T426] RSP: 0018:ffffc900025f77c8 EFLAGS: 00010203 [ 86.399273][ T426] RAX: 0000000020000001 RBX: 000000010000000e RCX: ffffffff83ed8610 [ 86.399281][ T426] RDX: 0000000000000000 RSI: ffffffff83ed8663 RDI: 0000000000000003 [ 86.399290][ T426] RBP: ffffc900025f7958 R08: ffff8880a8084400 R09: ffff8880a8084c90 [ 86.399299][ T426] R10: fffffbfff14f66d8 R11: ffffffff8a7b36c7 R12: dffffc0000000000 [ 86.399306][ T426] R13: 0000000000000000 R14: ffff88808d470000 R15: 000000000000075e [ 86.399317][ T426] FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 [ 86.399326][ T426] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 86.399334][ T426] CR2: 00007fc5380bb000 CR3: 00000000a6fbc000 CR4: 00000000001406e0 [ 86.399345][ T426] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 86.399353][ T426] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 86.399357][ T426] Call Trace: [ 86.399383][ T426] ? do_con_trol+0x61b0/0x61b0 [ 86.399401][ T426] ? n_tty_receive_buf_common+0xc3a/0x2b70 [ 86.399418][ T426] ? do_con_write.part.0+0x1ef0/0x1ef0 [ 86.399432][ T426] con_put_char+0xfa/0x110 [ 86.399448][ T426] ? do_con_write.part.0+0x1ef0/0x1ef0 [ 86.399463][ T426] ? n_tty_receive_buf_common+0xc4e/0x2b70 [ 86.399478][ T426] ? mutex_trylock+0x2d0/0x2d0 [ 86.399494][ T426] tty_put_char+0xc5/0x160 [ 86.399507][ T426] ? tty_hung_up_p+0x70/0x70 [ 86.399522][ T426] ? wait_for_completion+0x440/0x440 [ 86.399539][ T426] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 86.399553][ T426] ? con_write_room+0x5d/0x70 [ 86.399568][ T426] __process_echoes+0x5c8/0xa40 [ 86.399588][ T426] n_tty_receive_buf_common+0xc77/0x2b70 [ 86.399613][ T426] n_tty_receive_buf2+0x34/0x40 [ 86.399627][ T426] tty_ldisc_receive_buf+0xad/0x1c0 [ 86.399640][ T426] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 86.399654][ T426] ? n_tty_receive_buf_common+0x2b70/0x2b70 [ 86.399669][ T426] tty_port_default_receive_buf+0x7d/0xb0 [ 86.399682][ T426] flush_to_ldisc+0x222/0x390 [ 86.399700][ T426] process_one_work+0x9af/0x1740 [ 86.399716][ T426] ? pwq_dec_nr_in_flight+0x320/0x320 [ 86.399727][ T426] ? lock_acquire+0x190/0x410 [ 86.399744][ T426] worker_thread+0x98/0xe40 [ 86.399761][ T426] kthread+0x361/0x430 [ 86.399774][ T426] ? process_one_work+0x1740/0x1740 [ 86.399784][ T426] ? kthread_mod_delayed_work+0x1f0/0x1f0 [ 86.399797][ T426] ret_from_fork+0x24/0x30 [ 86.399807][ T426] Modules linked in: [ 86.399865][ T426] ---[ end trace 954f37c039fa5e10 ]--- [ 86.399880][ T426] RIP: 0010:do_con_write.part.0+0xa01/0x1ef0 [ 86.399893][ T426] Code: 7e fe ff ff 45 01 ef e8 fd 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 [ 86.399899][ T426] RSP: 0018:ffffc900025f77c8 EFLAGS: 00010203 [ 86.399908][ T426] RAX: 0000000020000001 RBX: 000000010000000e RCX: ffffffff83ed8610 [ 86.399915][ T426] RDX: 0000000000000000 RSI: ffffffff83ed8663 RDI: 0000000000000003 [ 86.399924][ T426] RBP: ffffc900025f7958 R08: ffff8880a8084400 R09: ffff8880a8084c90 [ 86.399937][ T426] R10: fffffbfff14f66d8 R11: ffffffff8a7b36c7 R12: dffffc0000000000 [ 86.399945][ T426] R13: 0000000000000000 R14: ffff88808d470000 R15: 000000000000075e [ 86.399955][ T426] FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 [ 86.399964][ T426] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 86.399972][ T426] CR2: 00007fc5380bb000 CR3: 00000000a6fbc000 CR4: 00000000001406e0 [ 86.399980][ T426] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 86.399987][ T426] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 86.399993][ T426] Kernel panic - not syncing: Fatal exception [ 86.401431][ T426] Kernel Offset: disabled