------------[ cut here ]------------ refcount_t: increment on 0; use-after-free. WARNING: CPU: 0 PID: 9477 at lib/refcount.c:156 refcount_inc_checked /lib/refcount.c:156 [inline] WARNING: CPU: 0 PID: 9477 at lib/refcount.c:156 refcount_inc_checked+0x61/0x70 /lib/refcount.c:154 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 9477 Comm: syz-executor.0 Not tainted 5.2.0-next-20190717 #40 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 1f 49 64 06 31 ff 89 de e8 1b 85 35 fe 84 db 75 dd e8 d2 83 35 fe 48 c7 c7 80 11 c6 87 c6 05 ff 48 64 06 01 e8 b7 eb 06 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:ffff8880ae809bf0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000100 RSI: ffffffff815c3a26 RDI: ffffed1015d01370 RBP: ffff8880ae809c00 R08: ffff888093ff2100 R09: fffffbfff14a7b57 R10: fffffbfff14a7b56 R11: ffffffff8a53dab7 R12: ffff888095decd00 R13: ffff888095decce8 R14: ffff888095dec488 R15: ffff888095dec460 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+0x1605/0x1e73 /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:__raw_spin_unlock_irq /./include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x54/0x90 /kernel/locking/spinlock.c:199 Code: c0 a0 f0 d2 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 33 48 83 3d 35 ef 98 01 00 74 20 fb 66 0f 1f 44 00 00 01 00 00 00 e8 f2 ab 14 fa 65 8b 05 03 fc c7 78 85 c0 74 06 41 RSP: 0018:ffff8880a474fb20 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11a5e14 RBX: ffff888093ff2100 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffff888093ff2994 RBP: ffff8880a474fb28 R08: ffff888093ff2100 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880ae835580 R13: ffffffff88c7a1c0 R14: ffff88808bd60b40 R15: 0000000000000000 finish_lock_switch /kernel/sched/core.c:3004 [inline] finish_task_switch+0x147/0x720 /kernel/sched/core.c:3104 context_switch /kernel/sched/core.c:3257 [inline] __schedule+0x75d/0x1580 /kernel/sched/core.c:3880 schedule+0xa8/0x270 /kernel/sched/core.c:3944 freezable_schedule /./include/linux/freezer.h:172 [inline] do_nanosleep+0x201/0x6a0 /kernel/time/hrtimer.c:1679 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: 0033:0x457ce1 Code: 75 14 b8 23 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 24 d3 fb ff c3 48 83 ec 08 e8 ea 46 00 00 48 89 04 24 b8 23 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 33 47 00 00 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007ffc0b3a5ae0 EFLAGS: 00000293 ORIG_RAX: 0000000000000023 RAX: ffffffffffffffda RBX: 00000000000184ab RCX: 0000000000457ce1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007ffc0b3a5af0 RBP: 0000000000000001 R08: ffffffffffffffff R09: ffffffffffffffff R10: 00007ffc0b3a5be0 R11: 0000000000000293 R12: 000000000075bf20 R13: 000000000075c9a0 R14: 0000000000760a68 R15: ffffffffffffffff Kernel Offset: disabled Rebooting in 86400 seconds..