[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [ 61.339488][ T27] audit: type=1800 audit(1575985608.320:25): pid=8967 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="cron" dev="sda1" ino=2414 res=0 [ 61.360105][ T27] audit: type=1800 audit(1575985608.320:26): pid=8967 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="mcstrans" dev="sda1" ino=2457 res=0 [ 61.405397][ T27] audit: type=1800 audit(1575985608.330:27): pid=8967 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 '10.128.0.225' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 69.864389][ T9119] BUG: kernel NULL pointer dereference, address: 0000000000000003 [ 69.872204][ T9119] #PF: supervisor write access in kernel mode [ 69.878278][ T9119] #PF: error_code(0x0002) - not-present page [ 69.884233][ T9119] PGD a97e6067 P4D a97e6067 PUD a8ddb067 PMD 0 [ 69.890455][ T9119] Oops: 0002 [#1] PREEMPT SMP KASAN [ 69.895649][ T9119] CPU: 0 PID: 9119 Comm: syz-executor861 Not tainted 5.5.0-rc1-syzkaller #0 [ 69.904295][ T9119] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 69.914352][ T9119] RIP: 0010:mem_serial_out+0x70/0x90 [ 69.919615][ T9119] Code: e9 00 00 00 49 8d 7c 24 40 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 d3 e3 80 3c 02 00 75 19 48 63 db 49 03 5c 24 40 <44> 88 2b 5b 41 5c 41 5d 5d c3 e8 61 45 cf fd eb c0 e8 ba 45 cf fd [ 69.939201][ T9119] RSP: 0018:ffffc90002ed7908 EFLAGS: 00010206 [ 69.945256][ T9119] RAX: dffffc0000000000 RBX: 0000000000000003 RCX: 0000000000000000 [ 69.953234][ T9119] RDX: 1ffffffff182080e RSI: ffffffff83e38076 RDI: ffffffff8c104070 [ 69.961286][ T9119] RBP: ffffc90002ed7920 R08: ffff888095492180 R09: ffffed104313a1c6 [ 69.969238][ T9119] R10: ffffed104313a1c5 R11: ffff8882189d0e2b R12: ffffffff8c104030 [ 69.977186][ T9119] R13: 00000000000000bf R14: ffffc90002ed7a40 R15: ffffffff8c104188 [ 69.985152][ T9119] FS: 0000000000f1c880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 [ 69.994071][ T9119] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 70.000638][ T9119] CR2: 0000000000000003 CR3: 00000000a8da6000 CR4: 00000000001406f0 [ 70.008613][ T9119] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 70.016666][ T9119] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 70.024886][ T9119] Call Trace: [ 70.028167][ T9119] serial8250_do_startup+0x12b9/0x1cf0 [ 70.033632][ T9119] serial8250_startup+0x62/0x80 [ 70.038603][ T9119] uart_startup+0x452/0x980 [ 70.043144][ T9119] ? uart_proc_show+0x13f0/0x13f0 [ 70.048155][ T9119] ? serial8250_request_std_resource+0x159/0x3d0 [ 70.054464][ T9119] ? serial8250_probe+0x680/0x680 [ 70.059477][ T9119] ? serial8250_request_port+0x16/0x20 [ 70.065031][ T9119] uart_set_info_user+0x13b4/0x1cf0 [ 70.070225][ T9119] ? uart_port_activate+0x200/0x200 [ 70.075412][ T9119] tty_ioctl+0xf60/0x14f0 [ 70.079739][ T9119] ? tty_vhangup+0x30/0x30 [ 70.084206][ T9119] ? tomoyo_path_number_perm+0x454/0x520 [ 70.089837][ T9119] ? __sanitizer_cov_trace_const_cmp1+0x1a/0x20 [ 70.096335][ T9119] ? tty_vhangup+0x30/0x30 [ 70.100739][ T9119] do_vfs_ioctl+0x977/0x14e0 [ 70.105315][ T9119] ? compat_ioctl_preallocate+0x220/0x220 [ 70.111015][ T9119] ? kmem_cache_free+0x26b/0x320 [ 70.115931][ T9119] ? putname+0xf4/0x130 [ 70.120077][ T9119] ? do_sys_open+0x31d/0x5d0 [ 70.124647][ T9119] ? tomoyo_file_ioctl+0x23/0x30 [ 70.129563][ T9119] ? __sanitizer_cov_trace_const_cmp4+0x16/0x20 [ 70.135779][ T9119] ? security_file_ioctl+0x8d/0xc0 [ 70.140874][ T9119] ksys_ioctl+0xab/0xd0 [ 70.145024][ T9119] __x64_sys_ioctl+0x73/0xb0 [ 70.149611][ T9119] do_syscall_64+0xfa/0x790 [ 70.154125][ T9119] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 70.160002][ T9119] RIP: 0033:0x440219 [ 70.163879][ T9119] Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00 [ 70.183750][ T9119] RSP: 002b:00007ffe693a0888 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 70.192181][ T9119] RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440219 [ 70.200133][ T9119] RDX: 0000000020000080 RSI: 000000000000541f RDI: 0000000000000003 [ 70.208084][ T9119] RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8 [ 70.216044][ T9119] R10: 0000000000401b30 R11: 0000000000000246 R12: 0000000000401aa0 [ 70.224003][ T9119] R13: 0000000000401b30 R14: 0000000000000000 R15: 0000000000000000 [ 70.231956][ T9119] Modules linked in: [ 70.235842][ T9119] CR2: 0000000000000003 [ 70.240322][ T9119] ---[ end trace 7a3cd380eb05e04d ]--- [ 70.245943][ T9119] RIP: 0010:mem_serial_out+0x70/0x90 [ 70.251213][ T9119] Code: e9 00 00 00 49 8d 7c 24 40 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 d3 e3 80 3c 02 00 75 19 48 63 db 49 03 5c 24 40 <44> 88 2b 5b 41 5c 41 5d 5d c3 e8 61 45 cf fd eb c0 e8 ba 45 cf fd [ 70.270840][ T9119] RSP: 0018:ffffc90002ed7908 EFLAGS: 00010206 [ 70.276926][ T9119] RAX: dffffc0000000000 RBX: 0000000000000003 RCX: 0000000000000000 [ 70.284964][ T9119] RDX: 1ffffffff182080e RSI: ffffffff83e38076 RDI: ffffffff8c104070 [ 70.292955][ T9119] RBP: ffffc90002ed7920 R08: ffff888095492180 R09: ffffed104313a1c6 [ 70.300941][ T9119] R10: ffffed104313a1c5 R11: ffff8882189d0e2b R12: ffffffff8c104030 [ 70.308946][ T9119] R13: 00000000000000bf R14: ffffc90002ed7a40 R15: ffffffff8c104188 [ 70.316936][ T9119] FS: 0000000000f1c880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 [ 70.325881][ T9119] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 70.332454][ T9119] CR2: 0000000000000003 CR3: 00000000a8da6000 CR4: 00000000001406f0 [ 70.341949][ T9119] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 70.349973][ T9119] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 70.358211][ T9119] Kernel panic - not syncing: Fatal exception [ 70.365653][ T9119] Kernel Offset: disabled [ 70.370020][ T9119] Rebooting in 86400 seconds..