[ OK ] Started Serial Getty on ttyS0. [ OK ] Reached target Login Prompts. [ OK ] Started OpenBSD Secure Shell server. [ OK ] Listening on Load/Save RF Kill Switch Status /dev/rfkill Watch. [ OK ] Reached target Multi-User System. [ 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 '10.128.1.0' (ECDSA) to the list of known hosts. executing program syzkaller login: [ 32.570174] block nbd0: NBD_DISCONNECT [ 32.574507] kasan: CONFIG_KASAN_INLINE enabled [ 32.579070] kasan: GPF could be caused by NULL-ptr deref or user memory access [ 32.586410] general protection fault: 0000 [#1] PREEMPT SMP KASAN [ 32.592622] CPU: 0 PID: 8116 Comm: syz-executor299 Not tainted 4.19.211-syzkaller #0 [ 32.600476] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 [ 32.609820] RIP: 0010:__lock_acquire+0x1eb/0x3ff0 [ 32.614639] Code: 2b 29 00 00 48 81 c4 98 01 00 00 44 89 f8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 b3 2a 00 00 49 81 3e 20 f2 66 8c 0f 84 65 ff ff [ 32.633515] RSP: 0018:ffff888095227270 EFLAGS: 00010006 [ 32.638867] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 32.646123] RDX: 0000000000000022 RSI: 0000000000000000 RDI: 0000000000000001 [ 32.653368] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 32.660614] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 [ 32.667860] R13: ffff8880b144c0c0 R14: 0000000000000110 R15: 0000000000000001 [ 32.675106] FS: 0000555555a5b300(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 [ 32.683305] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 32.689162] CR2: 00007f48eae16150 CR3: 00000000add90000 CR4: 00000000003406f0 [ 32.696415] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 32.703662] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 32.710906] Call Trace: [ 32.713481] ? __lock_acquire+0x6de/0x3ff0 [ 32.717694] ? mark_held_locks+0xf0/0xf0 [ 32.721737] ? __lock_acquire+0x6de/0x3ff0 [ 32.725947] ? mark_held_locks+0xf0/0xf0 [ 32.729986] ? __free_object+0xdd/0x1e0 [ 32.733937] ? mark_held_locks+0xf0/0xf0 [ 32.737977] ? mark_held_locks+0xa6/0xf0 [ 32.742017] lock_acquire+0x170/0x3c0 [ 32.745794] ? flush_workqueue+0xe8/0x13e0 [ 32.750003] flush_workqueue+0x117/0x13e0 [ 32.754135] ? flush_workqueue+0xe8/0x13e0 [ 32.758351] ? lock_downgrade+0x720/0x720 [ 32.762477] ? hctx_unlock+0x83/0x140 [ 32.766255] ? check_flush_dependency+0x400/0x400 [ 32.771080] nbd_disconnect_and_put+0x100/0x190 [ 32.775726] nbd_genl_disconnect+0x34f/0x4f0 [ 32.780111] ? nbd_release+0x170/0x170 [ 32.783981] ? nla_parse+0x1b2/0x290 [ 32.787674] genl_family_rcv_msg+0x642/0xc40 [ 32.792060] ? genl_rcv+0x40/0x40 [ 32.795497] ? genl_rcv_msg+0x12f/0x160 [ 32.799455] ? mutex_trylock+0x1a0/0x1a0 [ 32.803497] ? __radix_tree_lookup+0x216/0x370 [ 32.808063] genl_rcv_msg+0xbf/0x160 [ 32.811756] netlink_rcv_skb+0x160/0x440 [ 32.815793] ? genl_family_rcv_msg+0xc40/0xc40 [ 32.820357] ? netlink_ack+0xae0/0xae0 [ 32.824238] ? genl_rcv+0x15/0x40 [ 32.827681] genl_rcv+0x24/0x40 [ 32.830942] netlink_unicast+0x4d5/0x690 [ 32.835067] ? netlink_sendskb+0x110/0x110 [ 32.839437] ? _copy_from_iter_full+0x229/0x7c0 [ 32.844083] ? __phys_addr_symbol+0x2c/0x70 [ 32.848387] ? __check_object_size+0x17b/0x3e0 [ 32.852950] netlink_sendmsg+0x6c3/0xc50 [ 32.856992] ? aa_af_perm+0x230/0x230 [ 32.860769] ? nlmsg_notify+0x1f0/0x1f0 [ 32.864719] ? kernel_recvmsg+0x220/0x220 [ 32.868851] ? nlmsg_notify+0x1f0/0x1f0 [ 32.872808] sock_sendmsg+0xc3/0x120 [ 32.876498] ___sys_sendmsg+0x7bb/0x8e0 [ 32.880448] ? copy_msghdr_from_user+0x440/0x440 [ 32.885179] ? netlink_dump+0xc10/0xc10 [ 32.889241] ? nlmsg_notify+0x1f0/0x1f0 [ 32.893197] ? security_socket_recvmsg+0x8f/0xc0 [ 32.897930] ? __sys_recvfrom+0x2cd/0x3a0 [ 32.902149] ? __ia32_sys_send+0x100/0x100 [ 32.906361] ? __fdget+0x1a0/0x230 [ 32.909876] __x64_sys_sendmsg+0x132/0x220 [ 32.914086] ? __sys_sendmsg+0x1b0/0x1b0 [ 32.918130] ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe [ 32.923470] ? trace_hardirqs_off_caller+0x6e/0x210 [ 32.928467] ? do_syscall_64+0x21/0x620 [ 32.932504] do_syscall_64+0xf9/0x620 [ 32.936289] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 32.941461] RIP: 0033:0x7f48eada5e99 [ 32.945152] Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 14 00 00 90 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 [ 32.964030] RSP: 002b:00007ffe49d565c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 32.971711] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f48eada5e99 [ 32.978956] RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000005 [ 32.986201] RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffe49d56768 [ 32.993446] R10: 0000000000000000 R11: 0000000000000246 R12: 00007f48ead64c30 [ 33.000702] R13: 431bde82d7b634db R14: 0000000000000000 R15: 0000000000000000 [ 33.007949] Modules linked in: [ 33.011125] ---[ end trace f876e164e7b4e609 ]--- [ 33.015860] RIP: 0010:__lock_acquire+0x1eb/0x3ff0 [ 33.020677] Code: 2b 29 00 00 48 81 c4 98 01 00 00 44 89 f8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 b3 2a 00 00 49 81 3e 20 f2 66 8c 0f 84 65 ff ff [ 33.039554] RSP: 0018:ffff888095227270 EFLAGS: 00010006 [ 33.044910] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000 [ 33.052155] RDX: 0000000000000022 RSI: 0000000000000000 RDI: 0000000000000001 [ 33.059400] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 [ 33.066643] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 [ 33.073887] R13: ffff8880b144c0c0 R14: 0000000000000110 R15: 0000000000000001 [ 33.081144] FS: 0000555555a5b300(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000 [ 33.089354] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 33.095213] CR2: 00007f48eae16150 CR3: 00000000add90000 CR4: 00000000003406f0 [ 33.102470] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 33.109714] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 33.116958] Kernel panic - not syncing: Fatal exception [ 33.122466] Kernel Offset: disabled [ 33.126069] Rebooting in 86400 seconds..