------------[ cut here ]------------ refcount_t: increment on 0; use-after-free. WARNING: CPU: 1 PID: 7289 at lib/refcount.c:156 refcount_inc_checked+0x2b/0x30 lib/refcount.c:156 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 7289 Comm: udevd Not tainted 5.2.0-rc6+ #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x113/0x167 lib/dump_stack.c:113 panic+0x212/0x4cb kernel/panic.c:219 __warn.cold.8+0x1b/0x38 kernel/panic.c:576 report_bug+0x1a4/0x200 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:179 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:986 RIP: 0010:refcount_inc_checked+0x2b/0x30 lib/refcount.c:156 Code: 48 89 e5 e8 97 fe ff ff 84 c0 74 02 5d c3 80 3d c3 b1 f2 05 00 75 f5 48 c7 c7 40 51 41 87 c6 05 b3 b1 f2 05 01 e8 b8 a9 3d fe <0f> 0b 5d c3 90 55 48 89 e5 41 56 41 55 49 89 fd 48 c7 c7 a0 51 41 RSP: 0018:ffff8880aeb09c10 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff8880988bb500 RCX: 0000000000000000 RDX: 0000000000000004 RSI: ffff888098e7c968 RDI: ffffffff89d55d40 RBP: ffff8880aeb09c10 R08: 0000000000000002 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a764ac00 R13: ffff8880988bb568 R14: 000000000000000d R15: ffff8880988bb99e sock_hold include/net/sock.h:649 [inline] sk_add_node include/net/sock.h:701 [inline] nr_insert_socket+0x28/0xd0 net/netrom/af_netrom.c:137 nr_rx_frame+0x160f/0x1f00 net/netrom/af_netrom.c:1023 nr_loopback_timer+0x64/0x120 net/netrom/nr_loopback.c:59 call_timer_fn+0x14d/0x510 kernel/time/timer.c:1322 expire_timers kernel/time/timer.c:1366 [inline] __run_timers kernel/time/timer.c:1685 [inline] run_timer_softirq+0xc6f/0x1330 kernel/time/timer.c:1698 __do_softirq+0x260/0x958 kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x17f/0x1c0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x13e/0x540 arch/x86/kernel/apic/apic.c:1068 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:806 RIP: 0010:sockfd_lookup_light+0x1/0x150 net/socket.c:491 Code: 8b 55 e8 8b 75 ec e9 64 ff ff ff 89 55 ec e8 a6 ad 7a fc 8b 55 ec eb be 83 c8 ff c3 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 55 <48> 89 e5 41 57 41 56 41 55 49 89 d5 41 54 53 48 89 f3 48 83 ec 08 RSP: 0018:ffff88808f587d90 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: 1ffff11011eb0fb4 RCX: 0000000000000001 RDX: ffff88808f587dc0 RSI: ffff88808f587e00 RDI: 000000000000000b RBP: ffff88808f587ee8 R08: 0000000000000006 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88808f587ec0 R13: 00007ffebf9d0240 R14: ffff888098e7c0c0 R15: 0000000000000000 __do_sys_sendmsg net/socket.c:2333 [inline] __se_sys_sendmsg net/socket.c:2331 [inline] __x64_sys_sendmsg+0x73/0xb0 net/socket.c:2331 do_syscall_64+0xd0/0x530 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f386ac46320 Code: 02 48 83 c8 ff eb 8d 48 8b 05 14 7b 2a 00 f7 da 64 89 10 48 83 c8 ff eb c9 90 83 3d d5 d2 2a 00 00 75 10 b8 2e 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 5e ba 00 00 48 89 04 24 RSP: 002b:00007ffebf9d01f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f386ac46320 RDX: 0000000000000000 RSI: 00007ffebf9d0240 RDI: 000000000000000b RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffebf9d4080 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000011729f0 R13: 000000000000009b R14: 0000000000000000 R15: 000000000000000b Kernel Offset: disabled Rebooting in 86400 seconds..