------------[ cut here ]------------ refcount_t: increment on 0; use-after-free. WARNING: CPU: 0 PID: 27746 at lib/refcount.c:156 refcount_inc_checked /lib/refcount.c:156 [inline] WARNING: CPU: 0 PID: 27746 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: 27746 Comm: syz-executor.0 Not tainted 5.2.0-next-20190718 #41 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 5f 47 64 06 31 ff 89 de e8 db 80 35 fe 84 db 75 dd e8 92 7f 35 fe 48 c7 c7 80 0d c6 87 c6 05 3f 47 64 06 01 e8 77 e7 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: ffff8880535504c0 R09: fffffbfff14a7d64 R10: fffffbfff14a7d63 R11: ffffffff8a53eb1f R12: ffff88805f9a8d40 R13: ffff88805f9a8d28 R14: ffff88805fb3c088 R15: ffff88805fb3c060 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:rcu_dynticks_curr_cpu_in_eqs+0x87/0xb0 /kernel/rcu/tree.c:301 Code: 00 fc ff df 48 c1 ea 03 0f b6 14 02 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 17 8b 83 d8 00 00 00 48 83 c4 08 5b 41 5c <5d> d1 e8 83 f0 01 83 e0 01 c3 4c 89 e7 e8 c7 76 4c 00 eb df 48 89 RSP: 0018:ffff88805508f1f0 EFLAGS: 00000292 ORIG_RAX: ffffffffffffff13 RAX: 00000000001cd972 RBX: 0000000000000000 RCX: ffffffff81604a34 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880ae8363d8 RBP: ffff88805508f1f0 R08: 1ffff11015d06c7b R09: ffffed1015d06c7c R10: ffffed1015d06c7b R11: ffff8880ae8363db R12: ffff8880a9a673a1 R13: ffff8880a9a673a1 R14: dffffc0000000000 R15: 0000000000000000 rcu_is_watching+0x10/0x30 /kernel/rcu/tree.c:894 rcu_read_lock_held+0x81/0xd0 /kernel/rcu/update.c:266 rht_ptr_rcu /./include/linux/rhashtable.h:372 [inline] __rhashtable_walk_find_next+0x75c/0xbb0 /lib/rhashtable.c:794 rhashtable_walk_next+0x1e7/0x530 /lib/rhashtable.c:878 __netlink_diag_dump+0x188/0x770 /net/netlink/diag.c:121 netlink_diag_dump+0x1e4/0x28c /net/netlink/diag.c:196 netlink_dump+0x558/0xfa0 /net/netlink/af_netlink.c:2244 __netlink_dump_start+0x5b1/0x7d0 /net/netlink/af_netlink.c:2352 netlink_dump_start /./include/linux/netlink.h:233 [inline] netlink_diag_handler_dump+0x1c5/0x270 /net/netlink/diag.c:237 __sock_diag_cmd /net/core/sock_diag.c:232 [inline] sock_diag_rcv_msg+0x319/0x410 /net/core/sock_diag.c:263 netlink_rcv_skb+0x177/0x450 /net/netlink/af_netlink.c:2477 sock_diag_rcv+0x2b/0x40 /net/core/sock_diag.c:274 netlink_unicast_kernel /net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x531/0x710 /net/netlink/af_netlink.c:1328 netlink_sendmsg+0x8a5/0xd60 /net/netlink/af_netlink.c:1917 sock_sendmsg_nosec /net/socket.c:637 [inline] sock_sendmsg+0xd7/0x130 /net/socket.c:657 sock_write_iter+0x27c/0x3e0 /net/socket.c:989 call_write_iter /./include/linux/fs.h:1870 [inline] do_iter_readv_writev+0x5f8/0x8f0 /fs/read_write.c:693 do_iter_write /fs/read_write.c:970 [inline] do_iter_write+0x184/0x610 /fs/read_write.c:951 vfs_writev+0x1b3/0x2f0 /fs/read_write.c:1015 do_writev+0x15b/0x330 /fs/read_write.c:1058 __do_sys_writev /fs/read_write.c:1131 [inline] __se_sys_writev /fs/read_write.c:1128 [inline] __x64_sys_writev+0x75/0xb0 /fs/read_write.c:1128 do_syscall_64+0xfd/0x6a0 /arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459819 Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f345479cc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459819 RDX: 0000000000000001 RSI: 0000000020e11ff0 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f345479d6d4 R13: 00000000004c69f5 R14: 00000000004e0e70 R15: 00000000ffffffff Kernel Offset: disabled Rebooting in 86400 seconds..