Debian GNU/Linux 9 syzkaller ttyS0 Warning: Permanently added '10.128.0.46' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 28.201236] block nbd0: NBD_DISCONNECT [ 28.205661] kasan: CONFIG_KASAN_INLINE enabled [ 28.211904] kasan: GPF could be caused by NULL-ptr deref or user memory access [ 28.219733] general protection fault: 0000 [#1] PREEMPT SMP KASAN [ 28.226051] Modules linked in: [ 28.229500] CPU: 1 PID: 7963 Comm: syz-executor433 Not tainted 4.14.232-syzkaller #0 [ 28.237361] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 28.246782] task: ffff88809902e100 task.stack: ffff88809ce20000 [ 28.253258] RIP: 0010:__lock_acquire+0x1cc/0x3f20 [ 28.258166] RSP: 0018:ffff88809ce273b0 EFLAGS: 00010006 [ 28.264112] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 28.272004] RDX: 0000000000000022 RSI: 0000000000000000 RDI: 0000000000000110 [ 28.279259] RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 [ 28.286684] R10: 0000000000000001 R11: ffff88809902e100 R12: 0000000000000110 [ 28.294081] R13: 0000000000000000 R14: 0000000000000001 R15: ffffffff8bebbd40 [ 28.301438] FS: 0000000001233300(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000 [ 28.309656] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 28.315620] CR2: 0000000020000300 CR3: 0000000097f74000 CR4: 00000000001406e0 [ 28.323212] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 28.330670] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 28.338197] Call Trace: [ 28.341229] ? vprintk_emit+0x170/0x620 [ 28.345812] ? dev_vprintk_emit+0x1da/0x440 [ 28.350140] ? trace_hardirqs_on+0x10/0x10 [ 28.354800] ? dev_driver_string+0x160/0x160 [ 28.359614] ? trace_hardirqs_on+0x10/0x10 [ 28.364133] lock_acquire+0x170/0x3f0 [ 28.371823] ? flush_workqueue+0xcb/0x1310 [ 28.376258] flush_workqueue+0xfa/0x1310 [ 28.380414] ? flush_workqueue+0xcb/0x1310 [ 28.384718] ? nbd_disconnect_and_put+0x99/0x140 [ 28.389469] ? lock_downgrade+0x740/0x740 [ 28.393683] ? check_flush_dependency+0x2a0/0x2a0 [ 28.398506] nbd_disconnect_and_put+0xc3/0x140 [ 28.403068] nbd_genl_disconnect+0x1fa/0x320 [ 28.407505] genl_family_rcv_msg+0x572/0xb20 [ 28.412256] ? genl_rcv+0x40/0x40 [ 28.415803] ? __ww_mutex_wakeup_for_backoff+0x210/0x210 [ 28.421604] ? trace_hardirqs_on+0x10/0x10 [ 28.425819] ? sock_sendmsg+0xb5/0x100 [ 28.429837] genl_rcv_msg+0xaf/0x140 [ 28.433546] netlink_rcv_skb+0x125/0x390 [ 28.438049] ? genl_family_rcv_msg+0xb20/0xb20 [ 28.442908] ? netlink_ack+0x9a0/0x9a0 [ 28.447005] ? lock_acquire+0x170/0x3f0 [ 28.451080] genl_rcv+0x24/0x40 [ 28.454355] netlink_unicast+0x437/0x610 [ 28.458610] ? netlink_sendskb+0xd0/0xd0 [ 28.463313] ? __check_object_size+0x179/0x230 [ 28.468997] netlink_sendmsg+0x62e/0xb80 [ 28.473077] ? nlmsg_notify+0x170/0x170 [ 28.477658] ? kernel_recvmsg+0x210/0x210 [ 28.481868] ? security_socket_sendmsg+0x83/0xb0 [ 28.486977] ? nlmsg_notify+0x170/0x170 [ 28.491260] sock_sendmsg+0xb5/0x100 [ 28.494956] ___sys_sendmsg+0x6c8/0x800 [ 28.499104] ? copy_msghdr_from_user+0x3b0/0x3b0 [ 28.503848] ? trace_hardirqs_on+0x10/0x10 [ 28.508086] ? trace_hardirqs_on+0x10/0x10 [ 28.512304] ? apparmor_file_alloc_security+0x129/0x800 [ 28.517750] ? rcu_lockdep_current_cpu_online+0xed/0x140 [ 28.523612] ? __lockdep_init_map+0x100/0x560 [ 28.528343] ? __fd_install+0x1ec/0x5c0 [ 28.532336] ? lock_acquire+0x170/0x3f0 [ 28.536475] ? lock_downgrade+0x740/0x740 [ 28.540612] ? __fdget+0x167/0x1f0 [ 28.544364] ? sockfd_lookup_light+0xb2/0x160 [ 28.549556] __sys_sendmsg+0xa3/0x120 [ 28.553363] ? SyS_shutdown+0x160/0x160 [ 28.557316] ? move_addr_to_kernel+0x60/0x60 [ 28.561788] ? __do_page_fault+0x159/0xad0 [ 28.566383] SyS_sendmsg+0x27/0x40 [ 28.570047] ? __sys_sendmsg+0x120/0x120 [ 28.574273] do_syscall_64+0x1d5/0x640 [ 28.578153] entry_SYSCALL_64_after_hwframe+0x46/0xbb [ 28.583340] RIP: 0033:0x444069 [ 28.586509] RSP: 002b:00007ffc310d26a8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 28.594214] RAX: ffffffffffffffda RBX: 00000000004004b8 RCX: 0000000000444069 [ 28.601472] RDX: 0000000000000000 RSI: 0000000020000280 RDI: 0000000000000005 [ 28.608741] RBP: 0000000000403690 R08: 00000000004004b8 R09: 00000000004004b8 [ 28.616074] R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000403720 [ 28.623333] R13: 0000000000000000 R14: 00000000004b1018 R15: 00000000004004b8 [ 28.630787] 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 [ 28.650121] RIP: __lock_acquire+0x1cc/0x3f20 RSP: ffff88809ce273b0 [ 28.656423] ---[ end trace 2efd75fe454cddf7 ]--- [ 28.661152] Kernel panic - not syncing: Fatal exception [ 28.667473] Kernel Offset: disabled [ 28.671096] Rebooting in 86400 seconds..