===================================== WARNING: bad unlock balance detected! 4.16.0-rc2+ #323 Not tainted ------------------------------------- sshd/4099 is trying to release lock (rcu_read_lock_bh) at: [] rcu_read_unlock_bh include/linux/rcupdate.h:722 [inline] [] hashlimit_mt_common.isra.10+0x1beb/0x2610 net/netfilter/xt_hashlimit.c:777 but there are no more locks to release! other info that might help us debug this: 5 locks held by sshd/4099: #0: (sk_lock-AF_INET){+.+.}, at: [<00000000ebf89fa8>] lock_sock include/net/sock.h:1463 [inline] #0: (sk_lock-AF_INET){+.+.}, at: [<00000000ebf89fa8>] tcp_sendmsg+0x21/0x50 net/ipv4/tcp.c:1462 #1: (rcu_read_lock){....}, at: [<00000000b37d2092>] read_pnet include/net/net_namespace.h:280 [inline] #1: (rcu_read_lock){....}, at: [<00000000b37d2092>] sock_net include/net/sock.h:2305 [inline] #1: (rcu_read_lock){....}, at: [<00000000b37d2092>] ip_queue_xmit+0x9e/0x18e0 net/ipv4/ip_output.c:429 #2: ((&idev->mc_ifc_timer)){+.-.}, at: [<00000000c56d52a9>] lockdep_copy_map include/linux/lockdep.h:178 [inline] #2: ((&idev->mc_ifc_timer)){+.-.}, at: [<00000000c56d52a9>] call_timer_fn+0x1c6/0x820 kernel/time/timer.c:1316 #3: (rcu_read_lock){....}, at: [<0000000006738424>] read_pnet include/net/net_namespace.h:280 [inline] #3: (rcu_read_lock){....}, at: [<0000000006738424>] dev_net include/linux/netdevice.h:2050 [inline] #3: (rcu_read_lock){....}, at: [<0000000006738424>] mld_sendpack+0x180/0xe70 net/ipv6/mcast.c:1625 #4: (rcu_read_lock){....}, at: [<0000000080d48121>] nf_hook.constprop.37+0x0/0x830 net/ipv6/mcast.c:2795 stack backtrace: CPU: 1 PID: 4099 Comm: sshd Not tainted 4.16.0-rc2+ #323 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_unlock_imbalance_bug+0x12f/0x140 kernel/locking/lockdep.c:3484 __lock_release kernel/locking/lockdep.c:3691 [inline] lock_release+0x6fe/0xa40 kernel/locking/lockdep.c:3939 rcu_lock_release include/linux/rcupdate.h:249 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:724 [inline] hashlimit_mt_common.isra.10+0x1c08/0x2610 net/netfilter/xt_hashlimit.c:777 hashlimit_mt+0x78/0x90 net/netfilter/xt_hashlimit.c:846 ip6t_do_table+0x98d/0x1a30 net/ipv6/netfilter/ip6_tables.c:319 ip6table_raw_hook+0x65/0x80 net/ipv6/netfilter/ip6table_raw.c:42 nf_hook_entry_hookfn include/linux/netfilter.h:120 [inline] nf_hook_slow+0xba/0x1a0 net/netfilter/core.c:483 nf_hook.constprop.37+0x3f6/0x830 include/linux/netfilter.h:243 NF_HOOK include/linux/netfilter.h:286 [inline] mld_sendpack+0x6c2/0xe70 net/ipv6/mcast.c:1658 mld_send_cr net/ipv6/mcast.c:1954 [inline] mld_ifc_timer_expire+0x3d9/0x770 net/ipv6/mcast.c:2451 call_timer_fn+0x228/0x820 kernel/time/timer.c:1326 expire_timers kernel/time/timer.c:1363 [inline] __run_timers+0x7ee/0xb70 kernel/time/timer.c:1666 run_timer_softirq+0x4c/0x70 kernel/time/timer.c:1692 __do_softirq+0x2d7/0xb85 kernel/softirq.c:285 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1011 do_softirq.part.19+0x14d/0x190 kernel/softirq.c:329 do_softirq kernel/softirq.c:177 [inline] __local_bh_enable_ip+0x1ee/0x230 kernel/softirq.c:182 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:726 [inline] ip_finish_output2+0x962/0x1550 net/ipv4/ip_output.c:231 ip_finish_output+0x864/0xd10 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:277 [inline] ip_output+0x1d2/0x860 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:443 [inline] ip_local_out+0x95/0x160 net/ipv4/ip_output.c:124 ip_queue_xmit+0x8c0/0x18e0 net/ipv4/ip_output.c:504 tcp_transmit_skb+0x1b12/0x38b0 net/ipv4/tcp_output.c:1176 tcp_write_xmit+0x689/0x5470 net/ipv4/tcp_output.c:2393 __tcp_push_pending_frames+0xa0/0x250 net/ipv4/tcp_output.c:2566 tcp_push+0x547/0x780 net/ipv4/tcp.c:726 tcp_sendmsg_locked+0x289a/0x3c70 net/ipv4/tcp.c:1426 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1463 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:764 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg+0xca/0x110 net/socket.c:640 sock_write_iter+0x31a/0x5d0 net/socket.c:909 call_write_iter include/linux/fs.h:1781 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x684/0x970 fs/read_write.c:482 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 do_syscall_64+0x280/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f635b3ee370 RSP: 002b:00007ffc2ed89d78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000038 RCX: 00007f635b3ee370 RDX: 0000000000000038 RSI: 0000560056344460 RDI: 0000000000000003 RBP: 0000560056344460 R08: 0000000000000001 R09: 0101010101010101 R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffc2ed89ddc R13: 00005600556b9fb4 R14: 0000000000000028 R15: 00005600556bbca0