------------[ cut here ]------------
refcount_t: increment on 0; use-after-free.
WARNING: CPU: 1 PID: 9889 at lib/refcount.c:156 refcount_inc_checked lib/refcount.c:156 [inline]
WARNING: CPU: 1 PID: 9889 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: 9889 Comm: syz-executor.0 Not tainted 5.2.0-rc7-next-20190703 #28
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:986
RIP: 0010:refcount_inc_checked lib/refcount.c:156 [inline]
RIP: 0010:refcount_inc_checked+0x61/0x70 lib/refcount.c:154
Code: 1d 19 21 64 06 31 ff 89 de e8 cb d0 36 fe 84 db 75 dd e8 82 cf 36 fe 48 c7 c7 e0 a3 c5 87 c6 05 f9 20 64 06 01 e8 f7 47 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: ffffffff815c0c96 RDI: ffffed1015d21370
RBP: ffff8880ae909c00 R08: ffff88809a13e3c0 R09: fffffbfff14a4158
R10: fffffbfff14a4157 R11: ffffffff8a520abf R12: ffff888064950c80
R13: ffff888064950c68 R14: ffff8880649b0cc8 R15: ffff8880649b0ca0
 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:807
 </IRQ>
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:767 [inline]
RIP: 0010:lock_release+0x4c0/0x960 kernel/locking/lockdep.c:4435
Code: 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 8c 03 00 00 48 83 3d 4f 3b 7a 07 00 0f 84 7f 01 00 00 48 8b bd 48 ff ff ff 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 01 c3 48 c7 03 00
RSP: 0018:ffff8880648578b8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff11a5cba RBX: 1ffff1100c90af1c RCX: 1ffff11013427d89
RDX: dffffc0000000000 RSI: 1ffff11013427d8b RDI: 0000000000000286
RBP: ffff888064857988 R08: 0000000000000001 R09: ffff88809a13ec50
R10: fffffbfff1346e8f R11: ffffffff89a3747f R12: ffff88809a13e3c0
R13: ffffffff81bbeaca R14: ffff888064857960 R15: ffff88809a13e3c0
 rcu_lock_release include/linux/rcupdate.h:213 [inline]
 rcu_read_unlock include/linux/rcupdate.h:646 [inline]
 dput+0x1e1/0x670 fs/dcache.c:847
 path_put fs/namei.c:482 [inline]
 nd_jump_link+0x6b/0x1d0 fs/namei.c:871
 proc_ns_get_link+0x189/0x1b0 fs/proc/namespaces.c:57
 get_link fs/namei.c:1082 [inline]
 trailing_symlink+0x785/0x990 fs/namei.c:2261
 path_openat+0xa95/0x4630 fs/namei.c:3535
 do_filp_open+0x1a1/0x280 fs/namei.c:3563
 do_sys_open+0x3fe/0x5d0 fs/open.c:1070
 __do_sys_open fs/open.c:1088 [inline]
 __se_sys_open fs/open.c:1083 [inline]
 __x64_sys_open+0x7e/0xc0 fs/open.c:1083
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4136b1
Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 19 00 00 c3 48 83 ec 08 e8 0a fa ff ff 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007f0c86bf5c10 EFLAGS: 00000293 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004136b1
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000004be36e
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00007f0c86bf66d4
R13: 00000000004c862b R14: 00000000004df218 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..