======================================================
WARNING: possible circular locking dependency detected
6.16.0-rc6-syzkaller-00037-ge2291551827f #0 Not tainted
------------------------------------------------------
kworker/0:1/10 is trying to acquire lock:
ffff888055022218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff888055022218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4136 [inline]
ffff888055022218 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{3:3}, at: __dev_queue_xmit+0x334c/0x43e0 net/core/dev.c:4679

but task is already holding lock:
ffff88805481e158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff88805481e158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4651 [inline]
ffff88805481e158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x3ba/0xcf0 net/sched/sch_generic.c:342

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}:
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       spin_lock include/linux/spinlock.h:351 [inline]
       __netif_tx_lock include/linux/netdevice.h:4651 [inline]
       sch_direct_xmit+0x3ba/0xcf0 net/sched/sch_generic.c:342
       __dev_xmit_skb net/core/dev.c:4102 [inline]
       __dev_queue_xmit+0x13c7/0x43e0 net/core/dev.c:4679
       dev_queue_xmit include/linux/netdevice.h:3355 [inline]
       neigh_resolve_output net/core/neighbour.c:1512 [inline]
       neigh_resolve_output+0x53a/0x940 net/core/neighbour.c:1492
       neigh_output include/net/neighbour.h:539 [inline]
       ip6_finish_output2+0xaeb/0x2020 net/ipv6/ip6_output.c:141
       __ip6_finish_output net/ipv6/ip6_output.c:215 [inline]
       ip6_finish_output+0x3f9/0x1360 net/ipv6/ip6_output.c:226
       NF_HOOK_COND include/linux/netfilter.h:306 [inline]
       ip6_output+0x1f9/0x540 net/ipv6/ip6_output.c:247
       dst_output include/net/dst.h:459 [inline]
       NF_HOOK include/linux/netfilter.h:317 [inline]
       NF_HOOK include/linux/netfilter.h:311 [inline]
       mld_sendpack+0x9e9/0x1220 net/ipv6/mcast.c:1868
       mld_send_cr net/ipv6/mcast.c:2169 [inline]
       mld_ifc_work+0x740/0xca0 net/ipv6/mcast.c:2702
       process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
       process_scheduled_works kernel/workqueue.c:3321 [inline]
       worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
       kthread+0x3c5/0x780 kernel/kthread.c:464
       ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #0 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2){+...}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3168 [inline]
       check_prevs_add kernel/locking/lockdep.c:3287 [inline]
       validate_chain kernel/locking/lockdep.c:3911 [inline]
       __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240
       lock_acquire kernel/locking/lockdep.c:5871 [inline]
       lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828
       __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
       spin_lock include/linux/spinlock.h:351 [inline]
       __dev_xmit_skb net/core/dev.c:4136 [inline]
       __dev_queue_xmit+0x334c/0x43e0 net/core/dev.c:4679
       dev_queue_xmit include/linux/netdevice.h:3355 [inline]
       neigh_resolve_output net/core/neighbour.c:1512 [inline]
       neigh_resolve_output+0x53a/0x940 net/core/neighbour.c:1492
       neigh_output include/net/neighbour.h:539 [inline]
       ip6_finish_output2+0xaeb/0x2020 net/ipv6/ip6_output.c:141
       __ip6_finish_output net/ipv6/ip6_output.c:215 [inline]
       ip6_finish_output+0x3f9/0x1360 net/ipv6/ip6_output.c:226
       NF_HOOK_COND include/linux/netfilter.h:306 [inline]
       ip6_output+0x1f9/0x540 net/ipv6/ip6_output.c:247
       dst_output include/net/dst.h:459 [inline]
       ip6_local_out+0xcd/0x4a0 net/ipv6/output_core.c:155
       ip6_send_skb+0x112/0x460 net/ipv6/ip6_output.c:1982
       ip6_push_pending_frames+0xe0/0x110 net/ipv6/ip6_output.c:2003
       icmpv6_push_pending_frames+0x2dc/0x460 net/ipv6/icmp.c:311
       icmp6_send+0x1ec9/0x2be0 net/ipv6/icmp.c:632
       __icmpv6_send include/linux/icmpv6.h:28 [inline]
       icmpv6_send include/linux/icmpv6.h:49 [inline]
       ip6_link_failure+0x31/0x5a0 net/ipv6/route.c:2843
       dst_link_failure include/net/dst.h:429 [inline]
       ip_tunnel_xmit+0x2fb0/0x37b0 net/ipv4/ip_tunnel.c:865
       __gre_xmit+0x8bb/0xc00 net/ipv4/ip_gre.c:488
       erspan_xmit+0x56b/0x25d0 net/ipv4/ip_gre.c:747
       __netdev_start_xmit include/linux/netdevice.h:5215 [inline]
       netdev_start_xmit include/linux/netdevice.h:5224 [inline]
       xmit_one net/core/dev.c:3830 [inline]
       dev_hard_start_xmit+0x97/0x740 net/core/dev.c:3846
       sch_direct_xmit+0x1b2/0xcf0 net/sched/sch_generic.c:344
       qdisc_restart net/sched/sch_generic.c:409 [inline]
       __qdisc_run+0x541/0x1bf0 net/sched/sch_generic.c:417
       __dev_xmit_skb net/core/dev.c:4171 [inline]
       __dev_queue_xmit+0x2aa4/0x43e0 net/core/dev.c:4679
       dev_queue_xmit include/linux/netdevice.h:3355 [inline]
       neigh_hh_output include/net/neighbour.h:523 [inline]
       neigh_output include/net/neighbour.h:537 [inline]
       ip6_finish_output2+0xe98/0x2020 net/ipv6/ip6_output.c:141
       __ip6_finish_output net/ipv6/ip6_output.c:215 [inline]
       ip6_finish_output+0x3f9/0x1360 net/ipv6/ip6_output.c:226
       NF_HOOK_COND include/linux/netfilter.h:306 [inline]
       ip6_output+0x1f9/0x540 net/ipv6/ip6_output.c:247
       dst_output include/net/dst.h:459 [inline]
       ip6_local_out+0xcd/0x4a0 net/ipv6/output_core.c:155
       ip6tunnel_xmit include/net/ip6_tunnel.h:161 [inline]
       ip6_tnl_xmit+0x1960/0x3aa0 net/ipv6/ip6_tunnel.c:1281
       __gre6_xmit+0x473/0x1110 net/ipv6/ip6_gre.c:816
       ip6gre_xmit_ipv6 net/ipv6/ip6_gre.c:874 [inline]
       ip6gre_tunnel_xmit+0x6ac/0x10e0 net/ipv6/ip6_gre.c:926
       __netdev_start_xmit include/linux/netdevice.h:5215 [inline]
       netdev_start_xmit include/linux/netdevice.h:5224 [inline]
       xmit_one net/core/dev.c:3830 [inline]
       dev_hard_start_xmit+0x97/0x740 net/core/dev.c:3846
       sch_direct_xmit+0x1b2/0xcf0 net/sched/sch_generic.c:344
       __dev_xmit_skb net/core/dev.c:4102 [inline]
       __dev_queue_xmit+0x13c7/0x43e0 net/core/dev.c:4679
       dev_queue_xmit include/linux/netdevice.h:3355 [inline]
       neigh_hh_output include/net/neighbour.h:523 [inline]
       neigh_output include/net/neighbour.h:537 [inline]
       ip6_finish_output2+0xe98/0x2020 net/ipv6/ip6_output.c:141
       __ip6_finish_output net/ipv6/ip6_output.c:215 [inline]
       ip6_finish_output+0x3f9/0x1360 net/ipv6/ip6_output.c:226
       NF_HOOK_COND include/linux/netfilter.h:306 [inline]
       ip6_output+0x1f9/0x540 net/ipv6/ip6_output.c:247
       dst_output include/net/dst.h:459 [inline]
       NF_HOOK include/linux/netfilter.h:317 [inline]
       NF_HOOK include/linux/netfilter.h:311 [inline]
       mld_sendpack+0x9e9/0x1220 net/ipv6/mcast.c:1868
       mld_send_cr net/ipv6/mcast.c:2169 [inline]
       mld_ifc_work+0x740/0xca0 net/ipv6/mcast.c:2702
       process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
       process_scheduled_works kernel/workqueue.c:3321 [inline]
       worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
       kthread+0x3c5/0x780 kernel/kthread.c:464
       ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&qdisc_xmit_lock_key#4);
                               lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2);
                               lock(&qdisc_xmit_lock_key#4);
  lock(dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#2);

 *** DEADLOCK ***

15 locks held by kworker/0:1/10:
 #0: ffff888032de4948 ((wq_completion)mld){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
 #1: ffffc900000d7d10 ((work_completion)(&(&idev->mc_ifc_work)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
 #2: ffff888056cf7538 (&idev->mc_lock){+.+.}-{4:4}, at: mld_ifc_work+0x42/0xca0 net/ipv6/mcast.c:2701
 #3: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #3: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #3: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: mld_sendpack+0x1b3/0x1220 net/ipv6/mcast.c:1840
 #4: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #4: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #4: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: ip6_finish_output2+0x39d/0x2020 net/ipv6/ip6_output.c:126
 #5: ffffffff8e5c4da0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
 #5: ffffffff8e5c4da0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline]
 #5: ffffffff8e5c4da0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x276/0x43e0 net/core/dev.c:4638
 #6: ffff888026a0f258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:361 [inline]
 #6: ffff888026a0f258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:197 [inline]
 #6: ffff888026a0f258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:194 [inline]
 #6: ffff888026a0f258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4089 [inline]
 #6: ffff888026a0f258 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#3){+...}-{3:3}, at: __dev_queue_xmit+0x11a5/0x43e0 net/core/dev.c:4679
 #7: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #7: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #7: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: ip6_finish_output2+0x39d/0x2020 net/ipv6/ip6_output.c:126
 #8: ffffffff8e5c4da0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
 #8: ffffffff8e5c4da0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline]
 #8: ffffffff8e5c4da0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x276/0x43e0 net/core/dev.c:4638
 #9: ffff88805481e158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #9: ffff88805481e158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4651 [inline]
 #9: ffff88805481e158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x3ba/0xcf0 net/sched/sch_generic.c:342
 #10: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #10: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #10: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: icmp6_send+0x24c/0x2be0 net/ipv6/icmp.c:477
 #11: ffff8880330881d8 (k-slock-AF_INET6){+.-.}-{3:3}, at: spin_trylock include/linux/spinlock.h:361 [inline]
 #11: ffff8880330881d8 (k-slock-AF_INET6){+.-.}-{3:3}, at: icmpv6_xmit_lock net/ipv6/icmp.c:108 [inline]
 #11: ffff8880330881d8 (k-slock-AF_INET6){+.-.}-{3:3}, at: icmp6_send+0x8a5/0x2be0 net/ipv6/icmp.c:554
 #12: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #12: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #12: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: ip6_send_skb+0xb9/0x460 net/ipv6/ip6_output.c:1981
 #13: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #13: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #13: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: ip6_finish_output2+0x39d/0x2020 net/ipv6/ip6_output.c:126
 #14: ffffffff8e5c4da0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
 #14: ffffffff8e5c4da0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline]
 #14: ffffffff8e5c4da0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x276/0x43e0 net/core/dev.c:4638

stack backtrace:
CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.16.0-rc6-syzkaller-00037-ge2291551827f #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: mld mld_ifc_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2046
 check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2178
 check_prev_add kernel/locking/lockdep.c:3168 [inline]
 check_prevs_add kernel/locking/lockdep.c:3287 [inline]
 validate_chain kernel/locking/lockdep.c:3911 [inline]
 __lock_acquire+0x126f/0x1c90 kernel/locking/lockdep.c:5240
 lock_acquire kernel/locking/lockdep.c:5871 [inline]
 lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:351 [inline]
 __dev_xmit_skb net/core/dev.c:4136 [inline]
 __dev_queue_xmit+0x334c/0x43e0 net/core/dev.c:4679
 dev_queue_xmit include/linux/netdevice.h:3355 [inline]
 neigh_resolve_output net/core/neighbour.c:1512 [inline]
 neigh_resolve_output+0x53a/0x940 net/core/neighbour.c:1492
 neigh_output include/net/neighbour.h:539 [inline]
 ip6_finish_output2+0xaeb/0x2020 net/ipv6/ip6_output.c:141
 __ip6_finish_output net/ipv6/ip6_output.c:215 [inline]
 ip6_finish_output+0x3f9/0x1360 net/ipv6/ip6_output.c:226
 NF_HOOK_COND include/linux/netfilter.h:306 [inline]
 ip6_output+0x1f9/0x540 net/ipv6/ip6_output.c:247
 dst_output include/net/dst.h:459 [inline]
 ip6_local_out+0xcd/0x4a0 net/ipv6/output_core.c:155
 ip6_send_skb+0x112/0x460 net/ipv6/ip6_output.c:1982
 ip6_push_pending_frames+0xe0/0x110 net/ipv6/ip6_output.c:2003
 icmpv6_push_pending_frames+0x2dc/0x460 net/ipv6/icmp.c:311
 icmp6_send+0x1ec9/0x2be0 net/ipv6/icmp.c:632
 __icmpv6_send include/linux/icmpv6.h:28 [inline]
 icmpv6_send include/linux/icmpv6.h:49 [inline]
 ip6_link_failure+0x31/0x5a0 net/ipv6/route.c:2843
 dst_link_failure include/net/dst.h:429 [inline]
 ip_tunnel_xmit+0x2fb0/0x37b0 net/ipv4/ip_tunnel.c:865
 __gre_xmit+0x8bb/0xc00 net/ipv4/ip_gre.c:488
 erspan_xmit+0x56b/0x25d0 net/ipv4/ip_gre.c:747
 __netdev_start_xmit include/linux/netdevice.h:5215 [inline]
 netdev_start_xmit include/linux/netdevice.h:5224 [inline]
 xmit_one net/core/dev.c:3830 [inline]
 dev_hard_start_xmit+0x97/0x740 net/core/dev.c:3846
 sch_direct_xmit+0x1b2/0xcf0 net/sched/sch_generic.c:344
 qdisc_restart net/sched/sch_generic.c:409 [inline]
 __qdisc_run+0x541/0x1bf0 net/sched/sch_generic.c:417
 __dev_xmit_skb net/core/dev.c:4171 [inline]
 __dev_queue_xmit+0x2aa4/0x43e0 net/core/dev.c:4679
 dev_queue_xmit include/linux/netdevice.h:3355 [inline]
 neigh_hh_output include/net/neighbour.h:523 [inline]
 neigh_output include/net/neighbour.h:537 [inline]
 ip6_finish_output2+0xe98/0x2020 net/ipv6/ip6_output.c:141
 __ip6_finish_output net/ipv6/ip6_output.c:215 [inline]
 ip6_finish_output+0x3f9/0x1360 net/ipv6/ip6_output.c:226
 NF_HOOK_COND include/linux/netfilter.h:306 [inline]
 ip6_output+0x1f9/0x540 net/ipv6/ip6_output.c:247
 dst_output include/net/dst.h:459 [inline]
 ip6_local_out+0xcd/0x4a0 net/ipv6/output_core.c:155
 ip6tunnel_xmit include/net/ip6_tunnel.h:161 [inline]
 ip6_tnl_xmit+0x1960/0x3aa0 net/ipv6/ip6_tunnel.c:1281
 __gre6_xmit+0x473/0x1110 net/ipv6/ip6_gre.c:816
 ip6gre_xmit_ipv6 net/ipv6/ip6_gre.c:874 [inline]
 ip6gre_tunnel_xmit+0x6ac/0x10e0 net/ipv6/ip6_gre.c:926
 __netdev_start_xmit include/linux/netdevice.h:5215 [inline]
 netdev_start_xmit include/linux/netdevice.h:5224 [inline]
 xmit_one net/core/dev.c:3830 [inline]
 dev_hard_start_xmit+0x97/0x740 net/core/dev.c:3846
 sch_direct_xmit+0x1b2/0xcf0 net/sched/sch_generic.c:344
 __dev_xmit_skb net/core/dev.c:4102 [inline]
 __dev_queue_xmit+0x13c7/0x43e0 net/core/dev.c:4679
 dev_queue_xmit include/linux/netdevice.h:3355 [inline]
 neigh_hh_output include/net/neighbour.h:523 [inline]
 neigh_output include/net/neighbour.h:537 [inline]
 ip6_finish_output2+0xe98/0x2020 net/ipv6/ip6_output.c:141
 __ip6_finish_output net/ipv6/ip6_output.c:215 [inline]
 ip6_finish_output+0x3f9/0x1360 net/ipv6/ip6_output.c:226
 NF_HOOK_COND include/linux/netfilter.h:306 [inline]
 ip6_output+0x1f9/0x540 net/ipv6/ip6_output.c:247
 dst_output include/net/dst.h:459 [inline]
 NF_HOOK include/linux/netfilter.h:317 [inline]
 NF_HOOK include/linux/netfilter.h:311 [inline]
 mld_sendpack+0x9e9/0x1220 net/ipv6/mcast.c:1868
 mld_send_cr net/ipv6/mcast.c:2169 [inline]
 mld_ifc_work+0x740/0xca0 net/ipv6/mcast.c:2702
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3321 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3402
 kthread+0x3c5/0x780 kernel/kthread.c:464
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>