======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G             L     
------------------------------------------------------
kworker/1:7/5703 is trying to acquire lock:
ffff8880566ff558 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:347 [inline]
ffff8880566ff558 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4838 [inline]
ffff8880566ff558 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:370

but task is already holding lock:
ffff88802d741070 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:353 [inline]
ffff88802d741070 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&hsr->seqnr_lock){+.-.}-{3:3}:
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:182 [inline]
       _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:205
       spin_lock_bh include/linux/spinlock.h:353 [inline]
       hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
       __netdev_start_xmit include/linux/netdevice.h:5429 [inline]
       netdev_start_xmit include/linux/netdevice.h:5438 [inline]
       xmit_one net/core/dev.c:3937 [inline]
       dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3953
       __dev_queue_xmit+0x14c0/0x3820 net/core/dev.c:4926
       NF_HOOK+0x33a/0x3c0 include/linux/netfilter.h:-1
       arp_xmit+0x16c/0x270 net/ipv4/arp.c:665
       arp_solicit+0xbdc/0xe40 net/ipv4/arp.c:392
       neigh_probe net/core/neighbour.c:1093 [inline]
       __neigh_event_send+0xf0c/0x1510 net/core/neighbour.c:1273
       neigh_event_send_probe include/net/neighbour.h:480 [inline]
       neigh_event_send include/net/neighbour.h:486 [inline]
       neigh_resolve_output+0x1a1/0x720 net/core/neighbour.c:1600
       neigh_output include/net/neighbour.h:560 [inline]
       ip_finish_output2+0xc4b/0x10b0 net/ipv4/ip_output.c:236
       NF_HOOK_COND include/linux/netfilter.h:314 [inline]
       ip_output+0x29f/0x450 net/ipv4/ip_output.c:437
       iptunnel_xmit+0x626/0xd10 net/ipv4/ip_tunnel_core.c:97
       ip_tunnel_xmit+0x195b/0x2040 net/ipv4/ip_tunnel.c:848
       erspan_xmit+0xb6a/0x1620 net/ipv4/ip_gre.c:752
       __netdev_start_xmit include/linux/netdevice.h:5429 [inline]
       netdev_start_xmit include/linux/netdevice.h:5438 [inline]
       xmit_one net/core/dev.c:3937 [inline]
       dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3953
       sch_direct_xmit+0x257/0x4c0 net/sched/sch_generic.c:372
       __dev_xmit_skb net/core/dev.c:4262 [inline]
       __dev_queue_xmit+0x177f/0x3820 net/core/dev.c:4884
       dev_queue_xmit include/linux/netdevice.h:3461 [inline]
       alb_send_lp_vid+0x348/0x550 drivers/net/bonding/bond_alb.c:955
       alb_send_learning_packets+0x12c/0x300 drivers/net/bonding/bond_alb.c:1018
       bond_alb_monitor+0x3d0/0x1820 drivers/net/bonding/bond_alb.c:1569
       process_one_work kernel/workqueue.c:3396 [inline]
       process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
       worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
       kthread+0x38b/0x480 kernel/kthread.c:436
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #0 (&qdisc_xmit_lock_key#3){+.-.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3209 [inline]
       check_prevs_add kernel/locking/lockdep.c:3328 [inline]
       validate_chain kernel/locking/lockdep.c:3952 [inline]
       __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
       lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
       __raw_spin_lock include/linux/spinlock_api_smp.h:190 [inline]
       _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:173
       spin_lock include/linux/spinlock.h:347 [inline]
       __netif_tx_lock include/linux/netdevice.h:4838 [inline]
       sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:370
       __dev_xmit_skb net/core/dev.c:4262 [inline]
       __dev_queue_xmit+0x177f/0x3820 net/core/dev.c:4884
       dev_queue_xmit include/linux/netdevice.h:3461 [inline]
       hsr_xmit net/hsr/hsr_forward.c:440 [inline]
       hsr_forward_do net/hsr/hsr_forward.c:603 [inline]
       hsr_forward_skb+0x1701/0x2b70 net/hsr/hsr_forward.c:777
       hsr_dev_xmit+0x242/0x360 net/hsr/hsr_device.c:236
       __netdev_start_xmit include/linux/netdevice.h:5429 [inline]
       netdev_start_xmit include/linux/netdevice.h:5438 [inline]
       xmit_one net/core/dev.c:3937 [inline]
       dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3953
       __dev_queue_xmit+0x14c0/0x3820 net/core/dev.c:4926
       NF_HOOK_COND include/linux/netfilter.h:314 [inline]
       ip6_output+0x337/0x540 net/ipv6/ip6_output.c:248
       dst_output include/net/dst.h:472 [inline]
       NF_HOOK+0x177/0x4f0 include/linux/netfilter.h:325
       mld_sendpack+0x890/0xe10 net/ipv6/mcast.c:1890
       mld_send_cr net/ipv6/mcast.c:2191 [inline]
       mld_ifc_work+0x842/0xd60 net/ipv6/mcast.c:2739
       process_one_work kernel/workqueue.c:3396 [inline]
       process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
       worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
       kthread+0x38b/0x480 kernel/kthread.c:436
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       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(&hsr->seqnr_lock);
                               lock(&qdisc_xmit_lock_key#3);
                               lock(&hsr->seqnr_lock);
  lock(&qdisc_xmit_lock_key#3);

 *** DEADLOCK ***

locks held by kworker/1:7/5703: 11, last CPU#1:
 #0: ffff888033267d40 ((wq_completion)mld){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #0: ffff888033267d40 ((wq_completion)mld){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffff888033267d40 ((wq_completion)mld){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #0: ffff888033267d40 ((wq_completion)mld){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #1: ffffc90004c0fc40 ((work_completion)(&(&idev->mc_ifc_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #1: ffffc90004c0fc40 ((work_completion)(&(&idev->mc_ifc_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #1: ffffc90004c0fc40 ((work_completion)(&(&idev->mc_ifc_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline]
 #1: ffffc90004c0fc40 ((work_completion)(&(&idev->mc_ifc_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479
 #2: ffff88804cfd8530 (&idev->mc_lock){+.+.}-{4:4}, at: mld_ifc_work+0x2d/0xd60 net/ipv6/mcast.c:2738
 #3: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #3: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #3: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: mld_sendpack+0x206/0xe10 net/ipv6/mcast.c:1862
 #4: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #4: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #4: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: ip6_output+0x11e/0x540 net/ipv6/ip6_output.c:236
 #5: ffffffff8ed5c980 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
 #5: ffffffff8ed5c980 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:902 [inline]
 #5: ffffffff8ed5c980 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x29b/0x3820 net/core/dev.c:4844
 #6: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #6: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #6: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229
 #7: ffff88802d741070 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:353 [inline]
 #7: ffff88802d741070 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
 #8: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
 #8: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #8: ffffffff8ed5c920 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0xb9/0x2b70 net/hsr/hsr_forward.c:772
 #9: ffffffff8ed5c980 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
 #9: ffffffff8ed5c980 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:902 [inline]
 #9: ffffffff8ed5c980 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x29b/0x3820 net/core/dev.c:4844
 #10: ffff8880226c1228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:359 [inline]
 #10: ffff8880226c1228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:206 [inline]
 #10: ffff8880226c1228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4249 [inline]
 #10: ffff8880226c1228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#4){+...}-{3:3}, at: __dev_queue_xmit+0x1143/0x3820 net/core/dev.c:4884

stack backtrace:
CPU: 1 UID: 0 PID: 5703 Comm: kworker/1:7 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: mld mld_ifc_work
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087
 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2219
 check_prev_add kernel/locking/lockdep.c:3209 [inline]
 check_prevs_add kernel/locking/lockdep.c:3328 [inline]
 validate_chain kernel/locking/lockdep.c:3952 [inline]
 __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
 __raw_spin_lock include/linux/spinlock_api_smp.h:190 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:173
 spin_lock include/linux/spinlock.h:347 [inline]
 __netif_tx_lock include/linux/netdevice.h:4838 [inline]
 sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:370
 __dev_xmit_skb net/core/dev.c:4262 [inline]
 __dev_queue_xmit+0x177f/0x3820 net/core/dev.c:4884
 dev_queue_xmit include/linux/netdevice.h:3461 [inline]
 hsr_xmit net/hsr/hsr_forward.c:440 [inline]
 hsr_forward_do net/hsr/hsr_forward.c:603 [inline]
 hsr_forward_skb+0x1701/0x2b70 net/hsr/hsr_forward.c:777
 hsr_dev_xmit+0x242/0x360 net/hsr/hsr_device.c:236
 __netdev_start_xmit include/linux/netdevice.h:5429 [inline]
 netdev_start_xmit include/linux/netdevice.h:5438 [inline]
 xmit_one net/core/dev.c:3937 [inline]
 dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3953
 __dev_queue_xmit+0x14c0/0x3820 net/core/dev.c:4926
 NF_HOOK_COND include/linux/netfilter.h:314 [inline]
 ip6_output+0x337/0x540 net/ipv6/ip6_output.c:248
 dst_output include/net/dst.h:472 [inline]
 NF_HOOK+0x177/0x4f0 include/linux/netfilter.h:325
 mld_sendpack+0x890/0xe10 net/ipv6/mcast.c:1890
 mld_send_cr net/ipv6/mcast.c:2191 [inline]
 mld_ifc_work+0x842/0xd60 net/ipv6/mcast.c:2739
 process_one_work kernel/workqueue.c:3396 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
usb 2-1: USB disconnect, device number 22