[....] Starting enhanced syslogd: rsyslogd[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting periodic command scheduler: cron[?25l[?1c7[ ok 8[?25h[?0c. [....] Starting OpenBSD Secure Shell server: sshd[?25l[?1c7[ ok 8[?25h[?0c. [ 76.260327][ T27] kauditd_printk_skb: 4 callbacks suppressed [ 76.260337][ T27] audit: type=1800 audit(1584437931.533:29): pid=9866 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rc.local" dev="sda1" ino=2432 res=0 [ 76.304156][ T27] audit: type=1800 audit(1584437931.533:30): pid=9866 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="startpar" name="rmnologin" dev="sda1" ino=2423 res=0 Debian GNU/Linux 7 syzkaller ttyS0 Warning: Permanently added '10.128.0.235' (ECDSA) to the list of known hosts. 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 syzkaller login: [ 88.094184][T10208] general protection fault, probably for non-canonical address 0xdffffc0000000021: 0000 [#1] PREEMPT SMP KASAN [ 88.105923][T10208] KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f] [ 88.114309][T10208] CPU: 0 PID: 10208 Comm: blkid Not tainted 5.6.0-rc3-next-20200228-syzkaller #0 [ 88.123384][T10208] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 88.133422][T10208] RIP: 0010:destroy_workqueue+0x2e/0x6b0 [ 88.139052][T10208] Code: 49 89 fe 41 55 41 54 55 53 48 83 ec 08 e8 8a 6a 26 00 49 8d be 08 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 e0 05 00 00 49 8b 9e 08 01 00 00 48 85 db 74 19 [ 88.158811][T10208] RSP: 0018:ffffc90002227c30 EFLAGS: 00010206 [ 88.164913][T10208] RAX: dffffc0000000000 RBX: 0000000000000002 RCX: 0000000000000000 [ 88.172865][T10208] RDX: 0000000000000021 RSI: ffffffff814c2af6 RDI: 0000000000000108 [ 88.180813][T10208] RBP: ffff8880a1ae80f0 R08: ffff888094138380 R09: fffffbfff185270a [ 88.188870][T10208] R10: fffffbfff1852709 R11: ffffffff8c29384f R12: ffff8880a1ae8000 [ 88.196830][T10208] R13: ffff888091fe7b20 R14: 0000000000000000 R15: ffff888091fe7900 [ 88.204780][T10208] FS: 00007f516ab3a740(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 [ 88.213680][T10208] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 88.220244][T10208] CR2: 00007fee79ea3518 CR3: 0000000094fee000 CR4: 00000000001406f0 [ 88.228223][T10208] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 88.236187][T10208] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 88.244136][T10208] Call Trace: [ 88.247434][T10208] __loop_clr_fd+0x185/0x1280 [ 88.252111][T10208] lo_release+0x1ad/0x1e7 [ 88.256444][T10208] ? lo_compat_ioctl+0x110/0x110 [ 88.261488][T10208] __blkdev_put+0x509/0x690 [ 88.265985][T10208] ? freeze_bdev+0x1f0/0x1f0 [ 88.270553][T10208] ? blkdev_put+0x520/0x520 [ 88.275040][T10208] ? blkdev_put+0x85/0x520 [ 88.279481][T10208] ? blkdev_put+0x520/0x520 [ 88.284080][T10208] blkdev_close+0x86/0xb0 [ 88.288453][T10208] __fput+0x2da/0x850 [ 88.292417][T10208] task_work_run+0x13f/0x1b0 [ 88.296989][T10208] exit_to_usermode_loop+0x2fa/0x360 [ 88.302260][T10208] do_syscall_64+0x672/0x790 [ 88.306849][T10208] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 88.312732][T10208] RIP: 0033:0x7f516a4422b0 [ 88.317131][T10208] Code: 40 75 0b 31 c0 48 83 c4 08 e9 0c ff ff ff 48 8d 3d c5 32 08 00 e8 c0 07 02 00 83 3d 45 a3 2b 00 00 75 10 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ce 8a 01 00 48 89 04 24 [ 88.336738][T10208] RSP: 002b:00007fffd118fd48 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 [ 88.345141][T10208] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f516a4422b0 [ 88.353090][T10208] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 [ 88.361036][T10208] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 88.368979][T10208] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000021e8030 [ 88.376937][T10208] R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000005 [ 88.384893][T10208] Modules linked in: [ 88.389248][T10208] ---[ end trace 2b1aa5150b9419be ]--- [ 88.394896][T10208] RIP: 0010:destroy_workqueue+0x2e/0x6b0 [ 88.400693][T10208] Code: 49 89 fe 41 55 41 54 55 53 48 83 ec 08 e8 8a 6a 26 00 49 8d be 08 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 e0 05 00 00 49 8b 9e 08 01 00 00 48 85 db 74 19 [ 88.420426][T10208] RSP: 0018:ffffc90002227c30 EFLAGS: 00010206 [ 88.426522][T10208] RAX: dffffc0000000000 RBX: 0000000000000002 RCX: 0000000000000000 [ 88.434533][T10208] RDX: 0000000000000021 RSI: ffffffff814c2af6 RDI: 0000000000000108 [ 88.442525][T10208] RBP: ffff8880a1ae80f0 R08: ffff888094138380 R09: fffffbfff185270a [ 88.450503][T10208] R10: fffffbfff1852709 R11: ffffffff8c29384f R12: ffff8880a1ae8000 [ 88.458500][T10208] R13: ffff888091fe7b20 R14: 0000000000000000 R15: ffff888091fe7900 [ 88.466524][T10208] FS: 00007f516ab3a740(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 [ 88.475462][T10208] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 88.482144][T10208] CR2: 00007fee79ea3518 CR3: 0000000094fee000 CR4: 00000000001406f0 [ 88.490180][T10208] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 88.498198][T10208] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 88.506182][T10208] Kernel panic - not syncing: Fatal exception [ 88.513172][T10208] Kernel Offset: disabled [ 88.517492][T10208] Rebooting in 86400 seconds..