[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... [ OK ] Started Update UTMP about System Runlevel Changes. Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.180' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 30.373059] block nbd0: NBD_DISCONNECT [ 30.377470] kasan: CONFIG_KASAN_INLINE enabled [ 30.382044] kasan: GPF could be caused by NULL-ptr deref or user memory access [ 30.390157] general protection fault: 0000 [#1] PREEMPT SMP KASAN [ 30.397339] Modules linked in: [ 30.400754] CPU: 1 PID: 7975 Comm: syz-executor785 Not tainted 4.14.232-syzkaller #0 [ 30.409193] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 30.420133] task: ffff8880b37de000 task.stack: ffff888095880000 [ 30.426672] RIP: 0010:__lock_acquire+0x1cc/0x3f20 [ 30.431516] RSP: 0018:ffff8880958873b0 EFLAGS: 00010006 [ 30.437167] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 30.444704] RDX: 0000000000000022 RSI: 0000000000000000 RDI: 0000000000000110 [ 30.452429] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 [ 30.460013] R10: 0000000000000001 R11: ffff8880b37de000 R12: 0000000000000110 [ 30.468077] R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8bebbd40 [ 30.475901] FS: 0000000000f8b300(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 [ 30.484412] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 30.490616] CR2: 0000000020000080 CR3: 00000000af7fc000 CR4: 00000000001406e0 [ 30.499316] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 30.508004] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 30.517149] Call Trace: [ 30.519734] ? vprintk_emit+0x170/0x620 [ 30.523785] ? dev_vprintk_emit+0x1da/0x440 [ 30.528537] ? trace_hardirqs_on+0x10/0x10 [ 30.533090] ? dev_driver_string+0x160/0x160 [ 30.538411] ? trace_hardirqs_on+0x10/0x10 [ 30.543521] lock_acquire+0x170/0x3f0 [ 30.547331] ? flush_workqueue+0xcb/0x1310 [ 30.551858] flush_workqueue+0xfa/0x1310 [ 30.556443] ? flush_workqueue+0xcb/0x1310 [ 30.560929] ? nbd_disconnect_and_put+0x99/0x140 [ 30.566347] ? lock_downgrade+0x740/0x740 [ 30.570668] ? check_flush_dependency+0x2a0/0x2a0 [ 30.576117] nbd_disconnect_and_put+0xc3/0x140 [ 30.581322] nbd_genl_disconnect+0x1fa/0x320 [ 30.586037] genl_family_rcv_msg+0x572/0xb20 [ 30.590605] ? genl_rcv+0x40/0x40 [ 30.594577] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 30.600369] ? trace_hardirqs_on+0x10/0x10 [ 30.604857] ? sock_sendmsg+0xb5/0x100 [ 30.609023] genl_rcv_msg+0xaf/0x140 [ 30.612824] netlink_rcv_skb+0x125/0x390 [ 30.617134] ? genl_family_rcv_msg+0xb20/0xb20 [ 30.621708] ? netlink_ack+0x9a0/0x9a0 [ 30.625764] ? lock_acquire+0x170/0x3f0 [ 30.629811] genl_rcv+0x24/0x40 [ 30.633097] netlink_unicast+0x437/0x610 [ 30.637235] ? netlink_sendskb+0xd0/0xd0 [ 30.641308] ? __check_object_size+0x179/0x230 [ 30.645969] netlink_sendmsg+0x62e/0xb80 [ 30.650448] ? nlmsg_notify+0x170/0x170 [ 30.654405] ? kernel_recvmsg+0x210/0x210 [ 30.658658] ? security_socket_sendmsg+0x83/0xb0 [ 30.663741] ? nlmsg_notify+0x170/0x170 [ 30.667723] sock_sendmsg+0xb5/0x100 [ 30.671605] ___sys_sendmsg+0x6c8/0x800 [ 30.675834] ? copy_msghdr_from_user+0x3b0/0x3b0 [ 30.680689] ? netlink_dump+0xad0/0xad0 [ 30.684982] ? nlmsg_notify+0x170/0x170 [ 30.689071] ? security_socket_recvmsg+0x8b/0xc0 [ 30.693906] ? SyS_recvfrom+0x27f/0x340 [ 30.698528] ? SyS_send+0x40/0x40 [ 30.702092] ? __fdget+0x167/0x1f0 [ 30.705952] ? sockfd_lookup_light+0xb2/0x160 [ 30.711248] __sys_sendmsg+0xa3/0x120 [ 30.715553] ? SyS_shutdown+0x160/0x160 [ 30.719717] ? move_addr_to_kernel+0x60/0x60 [ 30.724202] ? __do_page_fault+0x159/0xad0 [ 30.728428] SyS_sendmsg+0x27/0x40 [ 30.731950] ? __sys_sendmsg+0x120/0x120 [ 30.736519] do_syscall_64+0x1d5/0x640 [ 30.740918] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 30.746408] RIP: 0033:0x444019 [ 30.750028] RSP: 002b:00007ffe360ee2f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 30.757903] RAX: ffffffffffffffda RBX: 00000000004004b8 RCX: 0000000000444019 [ 30.765962] RDX: 0000000000000000 RSI: 0000000020000540 RDI: 0000000000000004 [ 30.773879] RBP: 0000000000403640 R08: 0000000000000000 R09: 00000000004004b8 [ 30.781690] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004036d0 [ 30.789257] R13: 0000000000000000 R14: 00000000004b1018 R15: 00000000004004b8 [ 30.797509] Code: 18 00 00 00 00 48 81 c4 80 01 00 00 44 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 67 2a 00 00 49 81 3c 24 a0 77 2e 8b 0f 84 5f [ 30.817197] RIP: __lock_acquire+0x1cc/0x3f20 RSP: ffff8880958873b0 [ 30.823678] ---[ end trace 4956651e24430652 ]--- [ 30.828412] Kernel panic - not syncing: Fatal exception [ 30.835583] Kernel Offset: disabled [ 30.839487] Rebooting in 86400 seconds..