[ OK ] Reached target Graphical Interface. Starting Update UTMP about System Runlevel Changes... Starting Load/Save RF Kill Switch Status... [ OK ] Started Load/Save RF Kill Switch Status. [ OK ] Started Update UTMP about System Runlevel Changes. Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.124' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 29.355059] block nbd0: NBD_DISCONNECT [ 29.359396] kasan: CONFIG_KASAN_INLINE enabled [ 29.363951] kasan: GPF could be caused by NULL-ptr deref or user memory access [ 29.371283] general protection fault: 0000 [#1] PREEMPT SMP KASAN [ 29.377486] Modules linked in: [ 29.380654] CPU: 0 PID: 7975 Comm: syz-executor223 Not tainted 4.14.278-syzkaller #0 [ 29.388503] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 29.397827] task: ffff8880b56fa3c0 task.stack: ffff8880b36a8000 [ 29.403862] RIP: 0010:__lock_acquire+0x1cc/0x3f20 [ 29.408673] RSP: 0018:ffff8880b36af3b0 EFLAGS: 00010006 [ 29.414007] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 29.421249] RDX: 0000000000000022 RSI: 0000000000000000 RDI: 0000000000000110 [ 29.428489] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 [ 29.435731] R10: 0000000000000001 R11: ffff8880b56fa3c0 R12: 0000000000000110 [ 29.442971] R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8bed1d40 [ 29.450212] FS: 0000555556137300(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 [ 29.458407] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 29.464258] CR2: 00000000200000c0 CR3: 000000009956c000 CR4: 00000000003406f0 [ 29.471500] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 29.478751] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 29.485998] Call Trace: [ 29.488564] ? vprintk_emit+0x170/0x620 [ 29.492512] ? dev_vprintk_emit+0x1da/0x440 [ 29.496804] ? trace_hardirqs_on+0x10/0x10 [ 29.501008] ? dev_driver_string+0x160/0x160 [ 29.505384] ? trace_hardirqs_on+0x10/0x10 [ 29.509592] lock_acquire+0x170/0x3f0 [ 29.513362] ? flush_workqueue+0xcb/0x1310 [ 29.517566] flush_workqueue+0xfa/0x1310 [ 29.521600] ? flush_workqueue+0xcb/0x1310 [ 29.525809] ? nbd_disconnect_and_put+0x99/0x140 [ 29.530538] ? lock_downgrade+0x740/0x740 [ 29.534660] ? check_flush_dependency+0x2a0/0x2a0 [ 29.539475] nbd_disconnect_and_put+0xc3/0x140 [ 29.544028] nbd_genl_disconnect+0x1fa/0x320 [ 29.548413] genl_family_rcv_msg+0x572/0xb20 [ 29.552792] ? genl_rcv+0x40/0x40 [ 29.556217] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 29.561639] ? __kmalloc_node_track_caller+0x4c/0x70 [ 29.566714] ? trace_hardirqs_on+0x10/0x10 [ 29.570920] genl_rcv_msg+0xaf/0x140 [ 29.574607] netlink_rcv_skb+0x125/0x390 [ 29.578642] ? genl_family_rcv_msg+0xb20/0xb20 [ 29.583194] ? netlink_ack+0x9a0/0x9a0 [ 29.587066] ? lock_acquire+0x170/0x3f0 [ 29.591010] genl_rcv+0x24/0x40 [ 29.594259] netlink_unicast+0x437/0x610 [ 29.598290] ? netlink_sendskb+0xd0/0xd0 [ 29.602323] ? __check_object_size+0x179/0x230 [ 29.606875] netlink_sendmsg+0x648/0xbc0 [ 29.610906] ? nlmsg_notify+0x1b0/0x1b0 [ 29.614849] ? kernel_recvmsg+0x210/0x210 [ 29.618967] ? security_socket_sendmsg+0x83/0xb0 [ 29.623695] ? nlmsg_notify+0x1b0/0x1b0 [ 29.627641] sock_sendmsg+0xb5/0x100 [ 29.631324] ___sys_sendmsg+0x6c8/0x800 [ 29.635273] ? copy_msghdr_from_user+0x3b0/0x3b0 [ 29.640003] ? netlink_dump+0xb90/0xb90 [ 29.643947] ? nlmsg_notify+0x1b0/0x1b0 [ 29.647892] ? security_socket_recvmsg+0x8b/0xc0 [ 29.652617] ? SyS_recvfrom+0x27f/0x340 [ 29.656569] ? SyS_send+0x40/0x40 [ 29.659995] ? __fdget+0x167/0x1f0 [ 29.663507] ? sockfd_lookup_light+0xb2/0x160 [ 29.667972] __sys_sendmsg+0xa3/0x120 [ 29.671742] ? SyS_shutdown+0x160/0x160 [ 29.675690] ? move_addr_to_kernel+0x60/0x60 [ 29.680068] ? __do_page_fault+0x159/0xad0 [ 29.684277] SyS_sendmsg+0x27/0x40 [ 29.687791] ? __sys_sendmsg+0x120/0x120 [ 29.691823] do_syscall_64+0x1d5/0x640 [ 29.695687] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 29.700847] RIP: 0033:0x7fa241be21a9 [ 29.704527] RSP: 002b:00007ffc1faa6c18 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 29.712206] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa241be21a9 [ 29.719447] RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000005 [ 29.726693] RBP: 00007fa241ba17d0 R08: 0000000000000000 R09: 0000000000000000 [ 29.733930] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa241ba1860 [ 29.741169] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 29.748408] 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 d7 2f 8b 0f 84 5f [ 29.767448] RIP: __lock_acquire+0x1cc/0x3f20 RSP: ffff8880b36af3b0 [ 29.773740] ---[ end trace 4f541ab34ecd77eb ]--- [ 29.778463] Kernel panic - not syncing: Fatal exception [ 29.783962] Kernel Offset: disabled [ 29.787561] Rebooting in 86400 seconds..