------------[ cut here ]------------
refcount_t: increment on 0; use-after-free.
WARNING: CPU: 1 PID: 9245 at lib/refcount.c:156 refcount_inc_checked /lib/refcount.c:156 [inline]
WARNING: CPU: 1 PID: 9245 at lib/refcount.c:156 refcount_inc_checked+0x61/0x70 /lib/refcount.c:154
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 9245 Comm: udevd Not tainted 5.2.0+ #66
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack /lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 /lib/dump_stack.c:113
 panic+0x2dc/0x755 /kernel/panic.c:219
 __warn.cold+0x20/0x4c /kernel/panic.c:576
 report_bug+0x263/0x2b0 /lib/bug.c:186
 fixup_bug /arch/x86/kernel/traps.c:179 [inline]
 fixup_bug /arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0x11b/0x200 /arch/x86/kernel/traps.c:272
 do_invalid_op+0x37/0x50 /arch/x86/kernel/traps.c:291
 invalid_op+0x14/0x20 /arch/x86/entry/entry_64.S:1008
RIP: 0010:refcount_inc_checked /lib/refcount.c:156 [inline]
RIP: 0010:refcount_inc_checked+0x61/0x70 /lib/refcount.c:154
Code: 1d 50 c5 63 06 31 ff 89 de e8 4b 4a 37 fe 84 db 75 dd e8 02 49 37 fe 48 c7 c7 a0 1b c5 87 c6 05 30 c5 63 06 01 e8 e7 f2 08 fe <0f> 0b eb c1 90 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 41 57 41
RSP: 0018:ffff8880ae909bf0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000100 RSI: ffffffff815c1016 RDI: ffffed1015d21370
RBP: ffff8880ae909c00 R08: ffff8880a89b0540 R09: fffffbfff14a2770
R10: fffffbfff14a276f R11: ffffffff8a513b7f R12: ffff88806872e080
R13: ffff88806872e068 R14: ffff888063126248 R15: ffff888063126220
 sock_hold /./include/net/sock.h:649 [inline]
 sk_add_node /./include/net/sock.h:701 [inline]
 nr_insert_socket+0x2d/0xe0 /net/netrom/af_netrom.c:137
 nr_rx_frame+0x1605/0x1e80 /net/netrom/af_netrom.c:1023
 nr_loopback_timer+0x7b/0x170 /net/netrom/nr_loopback.c:59
 call_timer_fn+0x1ac/0x780 /kernel/time/timer.c:1322
 expire_timers /kernel/time/timer.c:1366 [inline]
 __run_timers /kernel/time/timer.c:1685 [inline]
 __run_timers /kernel/time/timer.c:1653 [inline]
 run_timer_softirq+0x697/0x17a0 /kernel/time/timer.c:1698
 __do_softirq+0x262/0x98c /kernel/softirq.c:292
 invoke_softirq /kernel/softirq.c:373 [inline]
 irq_exit+0x19b/0x1e0 /kernel/softirq.c:413
 exiting_irq /./arch/x86/include/asm/apic.h:537 [inline]
 smp_apic_timer_interrupt+0x1a3/0x610 /arch/x86/kernel/apic/apic.c:1095
 apic_timer_interrupt+0xf/0x20 /arch/x86/entry/entry_64.S:828
 </IRQ>
RIP: 0010:arch_local_irq_restore /./arch/x86/include/asm/paravirt.h:767 [inline]
RIP: 0010:kmem_cache_free+0xab/0x320 /mm/slab.c:3694
Code: e8 fa 26 00 00 84 c0 74 77 41 f7 c6 00 02 00 00 74 4f e8 a8 dc cb ff 48 83 3d 50 fb 26 07 00 0f 84 fa 01 00 00 4c 89 f7 57 9d <0f> 1f 44 00 00 4c 8b 6d 08 0f 1f 44 00 00 65 8b 05 70 a9 55 7e 83
RSP: 0018:ffff8880a65ffcf0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000007 RBX: ffff88809e224dc0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000286
RBP: ffff8880a65ffd10 R08: ffff8880a89b0540 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88821bc46380
R13: ffffffff81b97a9f R14: 0000000000000286 R15: 0000000000000000
 putname+0xef/0x130 /fs/namei.c:259
 do_renameat2+0x294/0xc40 /fs/namei.c:4646
 __do_sys_rename /fs/namei.c:4673 [inline]
 __se_sys_rename /fs/namei.c:4671 [inline]
 __x64_sys_rename+0x61/0x80 /fs/namei.c:4671
 do_syscall_64+0xfd/0x6a0 /arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fe2a4d8b527
Code: 32 00 64 83 38 15 74 07 b8 ff ff ff ff 5b c3 48 89 df e8 1c c1 07 00 85 c0 75 ed 31 c0 eb d3 90 90 90 90 b8 52 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 f8 32 00 31 d2 48 29 c2 64
RSP: 002b:00007fff85d89848 EFLAGS: 00000246 ORIG_RAX: 0000000000000052
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe2a4d8b527
RDX: 0000000000891d40 RSI: 00007fff85d89880 RDI: 00007fff85d89c80
RBP: 0000000000891720 R08: 00007fe2a56fe7a0 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000893440
R13: 0000000000891250 R14: 00007fff85d89880 R15: 0000000000000001
Kernel Offset: disabled
Rebooting in 86400 seconds..