loop4: p1 p3
------------[ cut here ]------------
WARNING: CPU: 1 PID: 4370 at net/ipv4/tcp_timer.c:429 tcp_retransmit_timer+0x1ac5/0x2560 net/ipv4/tcp_timer.c:429
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 4370 Comm: blkid Not tainted 4.14.145 #0
kobject: 'loop4p1' (ffff8880a9c54a98): kobject_uevent_env
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x138/0x197 lib/dump_stack.c:53
 panic+0x1f2/0x426 kernel/panic.c:182
kobject: 'loop4p1' (ffff8880a9c54a98): kobject_uevent_env: uevent_suppress caused the event to drop!
 __warn.cold+0x2f/0x36 kernel/panic.c:546
kobject: 'loop2' (ffff8880a4a36f20): fill_kobj_path: path = '/devices/virtual/block/loop2'
 report_bug+0x216/0x254 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+0x1bb/0x310 arch/x86/kernel/traps.c:295
kobject: 'holders' (ffff88809dd03c80): kobject_add_internal: parent: 'loop4p1', set: '<NULL>'
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:963
RIP: 0010:tcp_retransmit_timer+0x1ac5/0x2560 net/ipv4/tcp_timer.c:429
RSP: 0018:ffff8880aef07c88 EFLAGS: 00010206
kobject: 'loop4p1' (ffff8880a9c54a98): kobject_uevent_env
RAX: ffff88808e9a2000 RBX: ffff8880657859c0 RCX: 0000000000000014
RDX: 0000000000000100 RSI: ffff88809fa0128c RDI: ffff88809fa01458
RBP: ffff8880aef07ce8 R08: 0000024fb7e02b3f R09: ffff88821fff8048
R10: ffff88821fff8050 R11: 0000000000000001 R12: ffff88809fa00a80
R13: ffff88809fa0111a R14: ffff88809fa00ab0 R15: 0000000000000000
kobject: 'loop4p1' (ffff8880a9c54a98): fill_kobj_path: path = '/devices/virtual/block/loop4/loop4p1'
 tcp_write_timer_handler+0x479/0x7e0 net/ipv4/tcp_timer.c:579
 tcp_write_timer+0xd8/0x180 net/ipv4/tcp_timer.c:597
 call_timer_fn+0x161/0x670 kernel/time/timer.c:1279
kobject: 'loop5' (ffff8880a4b292a0): kobject_uevent_env
 expire_timers kernel/time/timer.c:1318 [inline]
 __run_timers kernel/time/timer.c:1634 [inline]
 __run_timers kernel/time/timer.c:1602 [inline]
 run_timer_softirq+0x5b4/0x1570 kernel/time/timer.c:1647
kobject: 'loop4p3' (ffff8880a8fed518): kobject_add_internal: parent: 'loop4', set: 'devices'
kobject: 'loop5' (ffff8880a4b292a0): fill_kobj_path: path = '/devices/virtual/block/loop5'
 __do_softirq+0x244/0x9a0 kernel/softirq.c:288
 invoke_softirq kernel/softirq.c:368 [inline]
 irq_exit+0x160/0x1b0 kernel/softirq.c:409
 exiting_irq arch/x86/include/asm/apic.h:648 [inline]
 smp_apic_timer_interrupt+0x146/0x5e0 arch/x86/kernel/apic/apic.c:1102
 apic_timer_interrupt+0x96/0xa0 arch/x86/entry/entry_64.S:792
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:779 [inline]
RIP: 0010:kmem_cache_free+0xb0/0x2b0 mm/slab.c:3759
RSP: 0018:ffff88807348fba8 EFLAGS: 00000282
kobject: 'loop4p3' (ffff8880a8fed518): kobject_uevent_env
 ORIG_RAX: ffffffffffffff10
RAX: 0000000000000007 RBX: ffff888096e62148 RCX: 1ffff11011d34514
RDX: 0000000000000000 RSI: ffff88808e9a2880 RDI: 0000000000000282
RBP: ffff88807348fbc8 R08: 000000008e8cffdd R09: ffff88808e9a28a0
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88821f830c40
R13: 0000000000000282 R14: ffffffff817ddfa1 R15: dffffc0000000000
 remove_vma+0x161/0x1b0 mm/mmap.c:177
 remove_vma_list mm/mmap.c:2511 [inline]
 do_munmap+0x61f/0xd60 mm/mmap.c:2752
kobject: 'loop4p3' (ffff8880a8fed518): kobject_uevent_env: uevent_suppress caused the event to drop!
 mmap_region+0x16f/0x1030 mm/mmap.c:1664
 do_mmap+0x5b8/0xcd0 mm/mmap.c:1501
 do_mmap_pgoff include/linux/mm.h:2178 [inline]
 vm_mmap_pgoff+0x17a/0x1d0 mm/util.c:333
kobject: 'holders' (ffff88808ff87600): kobject_add_internal: parent: 'loop4p3', set: '<NULL>'
 SYSC_mmap_pgoff mm/mmap.c:1551 [inline]
 SyS_mmap_pgoff+0x3ca/0x520 mm/mmap.c:1509
 SYSC_mmap arch/x86/kernel/sys_x86_64.c:100 [inline]
 SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:91
 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
kobject: 'loop4p3' (ffff8880a8fed518): kobject_uevent_env
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7f63c03ce3ea
RSP: 002b:00007ffc96ce6768 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f63c05d0000 RCX: 00007f63c03ce3ea
kobject: 'loop4p3' (ffff8880a8fed518): fill_kobj_path: path = '/devices/virtual/block/loop4/loop4p3'
RDX: 0000000000000003 RSI: 0000000000002000 RDI: 00007f63bfe02000
RBP: 00007ffc96ce6a60 R08: 0000000000000003 R09: 0000000000003000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffc96ce6b48
R13: 0000000000000002 R14: 00007ffc96ce67e0 R15: 00007ffc96ce67b0
Kernel Offset: disabled
Rebooting in 86400 seconds..