------------[ cut here ]------------ refcount_t: increment on 0; use-after-free. WARNING: CPU: 1 PID: 13834 at lib/refcount.c:156 refcount_inc_checked lib/refcount.c:156 [inline] WARNING: CPU: 1 PID: 13834 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: 13834 Comm: syz-executor288 Not tainted 5.2.0+ #59 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+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 9e 36 64 06 31 ff 89 de e8 9b 41 37 fe 84 db 75 dd e8 52 40 37 fe 48 c7 c7 c0 20 c5 87 c6 05 7e 36 64 06 01 e8 77 e9 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: ffffffff815c1196 RDI: ffffed1015d21370 RBP: ffff8880ae909c00 R08: ffff8880923c62c0 R09: fffffbfff14a3770 R10: fffffbfff14a376f R11: ffffffff8a51bb7f R12: ffff8880924e4f40 R13: ffff8880924e4f28 R14: ffff8880924e57c8 R15: ffff8880924e57a0 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 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:767 [inline] RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x95/0xe0 kernel/locking/spinlock.c:191 Code: 48 c7 c0 10 e5 d2 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 39 48 83 3d 42 26 9e 01 00 74 24 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 8c e9 19 fa 65 8b 05 9d 3e cd 78 RSP: 0018:ffff8880894afb78 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11a5ca2 RBX: 0000000000000282 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000006 RDI: 0000000000000282 RBP: ffff8880894afb88 R08: ffff8880923c62c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880ae926d00 R13: ffff8880894afdc0 R14: 0000000000026d00 R15: ffff8880ae926d80 unlock_hrtimer_base kernel/time/hrtimer.c:877 [inline] hrtimer_start_range_ns+0x665/0xcb0 kernel/time/hrtimer.c:1108 hrtimer_start_expires include/linux/hrtimer.h:395 [inline] do_nanosleep+0x19b/0x6a0 kernel/time/hrtimer.c:1676 hrtimer_nanosleep+0x2a6/0x570 kernel/time/hrtimer.c:1733 __do_sys_nanosleep kernel/time/hrtimer.c:1767 [inline] __se_sys_nanosleep kernel/time/hrtimer.c:1754 [inline] __x64_sys_nanosleep+0x1a6/0x220 kernel/time/hrtimer.c:1754 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x447481 Code: 75 14 b8 23 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 84 20 fc ff c3 48 83 ec 08 e8 6a 45 00 00 48 89 04 24 b8 23 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 b3 45 00 00 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007ffdfff87ae0 EFLAGS: 00000293 ORIG_RAX: 0000000000000023 RAX: ffffffffffffffda RBX: 0000000000000022 RCX: 0000000000447481 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffdfff87af0 RBP: 00000000006e4a1c R08: 00000000004b179d R09: 00000000004b179d R10: 00000000004b179d R11: 0000000000000293 R12: 00000000006e4a20 R13: 0000000000000003 R14: 000000000000002d R15: 20c49ba5e353f7cf Kernel Offset: disabled Rebooting in 86400 seconds..