block nbd3: Attempted send on invalid socket
print_req_error: I/O error, dev nbd3, sector 2
EXT4-fs (nbd3): unable to read superblock
------------[ cut here ]------------
WARNING: CPU: 1 PID: 17 at kernel/rcu/tree.c:2733 arch_local_irq_disable arch/x86/include/asm/paravirt.h:784 [inline]
WARNING: CPU: 1 PID: 17 at kernel/rcu/tree.c:2733 arch_local_irq_save arch/x86/include/asm/paravirt.h:797 [inline]
WARNING: CPU: 1 PID: 17 at kernel/rcu/tree.c:2733 rcu_do_batch kernel/rcu/tree.c:2711 [inline]
WARNING: CPU: 1 PID: 17 at kernel/rcu/tree.c:2733 invoke_rcu_callbacks kernel/rcu/tree.c:2962 [inline]
WARNING: CPU: 1 PID: 17 at kernel/rcu/tree.c:2733 __rcu_process_callbacks kernel/rcu/tree.c:2929 [inline]
WARNING: CPU: 1 PID: 17 at kernel/rcu/tree.c:2733 rcu_process_callbacks+0xe40/0x1180 kernel/rcu/tree.c:2946
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 17 Comm: ksoftirqd/1 Not tainted 4.14.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 panic+0x1f9/0x42d kernel/panic.c:183
 __warn.cold+0x20/0x4b kernel/panic.c:547
 report_bug+0x208/0x249 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x195/0x2d0 arch/x86/kernel/traps.c:295
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:964
RIP: 0010:rcu_do_batch kernel/rcu/tree.c:2733 [inline]
RIP: 0010:invoke_rcu_callbacks kernel/rcu/tree.c:2962 [inline]
RIP: 0010:__rcu_process_callbacks kernel/rcu/tree.c:2929 [inline]
RIP: 0010:rcu_process_callbacks+0xe40/0x1180 kernel/rcu/tree.c:2946
RSP: 0018:ffff8880a98c7d00 EFLAGS: 00010002
RAX: 1ffff11015d65800 RBX: ffff8880aeb2c180 RCX: 0000000000000000
RDX: 1ffff11015318f01 RSI: ffff8880a98c7d68 RDI: ffff8880aeb2c210
RBP: ffff8880aeb2c1b8 R08: ffffffff8950de24 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a98c7d68
R13: 000000000000000f R14: ffffffff87d87140 R15: dffffc0000000000
 __do_softirq+0x254/0xa1d kernel/softirq.c:288
 run_ksoftirqd+0x50/0x1a0 kernel/softirq.c:670
 smpboot_thread_fn+0x5c1/0x920 kernel/smpboot.c:164
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Kernel Offset: disabled
Rebooting in 86400 seconds..