======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kworker/u8:15/11209 is trying to acquire lock:
ffff888047b8cf30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffff888047b8cf30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235

but task is already holding lock:
ffff88807e156558 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
ffff88807e156558 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4710 [inline]
ffff88807e156558 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:345

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:4710 [inline]
       sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:345
       __dev_xmit_skb net/core/dev.c:4182 [inline]
       __dev_queue_xmit+0x1538/0x3850 net/core/dev.c:4798
       dev_queue_xmit include/linux/netdevice.h:3381 [inline]
       hsr_xmit net/hsr/hsr_forward.c:440 [inline]
       hsr_forward_do net/hsr/hsr_forward.c:581 [inline]
       hsr_forward_skb+0x15a0/0x2880 net/hsr/hsr_forward.c:743
       send_hsr_supervision_frame+0x731/0xcb0 net/hsr/hsr_device.c:364
       hsr_announce+0x1db/0x370 net/hsr/hsr_device.c:421
       call_timer_fn+0x192/0x5a0 kernel/time/timer.c:1748
       expire_timers kernel/time/timer.c:1799 [inline]
       __run_timers kernel/time/timer.c:2373 [inline]
       __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
       run_timer_base kernel/time/timer.c:2394 [inline]
       run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
       handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622
       do_softirq+0x76/0xd0 kernel/softirq.c:523
       __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
       netdev_for_each_tx_queue include/linux/netdevice.h:2680 [inline]
       dev_deactivate_many+0x720/0xd40 net/sched/sch_generic.c:1374
       __dev_close_many+0x17b/0x6d0 net/core/dev.c:1753
       netif_close_many+0x225/0x420 net/core/dev.c:1794
       unregister_netdevice_many_notify+0xb47/0x2370 net/core/dev.c:12366
       unregister_netdevice_many net/core/dev.c:12459 [inline]
       unregister_netdevice_queue+0x31f/0x360 net/core/dev.c:12273
       unregister_netdevice include/linux/netdevice.h:3405 [inline]
       __tun_detach+0x6d9/0x15d0 drivers/net/tun.c:621
       tun_detach drivers/net/tun.c:637 [inline]
       tun_chr_close+0x10a/0x1c0 drivers/net/tun.c:3436
       __fput+0x44f/0xa70 fs/file_table.c:468
       task_work_run+0x1d9/0x270 kernel/task_work.c:233
       resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
       __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
       exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:75
       __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
       syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
       syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
       syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
       do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&hsr->seqnr_lock){+.-.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3165 [inline]
       check_prevs_add kernel/locking/lockdep.c:3284 [inline]
       validate_chain kernel/locking/lockdep.c:3908 [inline]
       __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
       lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
       __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
       _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178
       spin_lock_bh include/linux/spinlock.h:356 [inline]
       hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
       __netdev_start_xmit include/linux/netdevice.h:5273 [inline]
       netdev_start_xmit include/linux/netdevice.h:5282 [inline]
       xmit_one net/core/dev.c:3866 [inline]
       dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3882
       __dev_queue_xmit+0x168f/0x3850 net/core/dev.c:4832
       NF_HOOK+0x33a/0x3c0 include/linux/netfilter.h:-1
       arp_xmit+0x16c/0x270 net/ipv4/arp.c:665
       arp_solicit+0xbe0/0xe40 net/ipv4/arp.c:392
       neigh_probe net/core/neighbour.c:1097 [inline]
       __neigh_event_send+0xf05/0x14a0 net/core/neighbour.c:1270
       neigh_event_send_probe include/net/neighbour.h:480 [inline]
       neigh_event_send include/net/neighbour.h:486 [inline]
       neigh_resolve_output+0x198/0x750 net/core/neighbour.c:1578
       neigh_output include/net/neighbour.h:556 [inline]
       ip_finish_output2+0xbb6/0xff0 net/ipv4/ip_output.c:237
       NF_HOOK_COND include/linux/netfilter.h:307 [inline]
       ip_output+0x29f/0x450 net/ipv4/ip_output.c:438
       iptunnel_xmit+0x59f/0xa00 net/ipv4/ip_tunnel_core.c:84
       ip_tunnel_xmit+0x1f74/0x2730 net/ipv4/ip_tunnel.c:845
       __gre_xmit+0x19e/0x240 net/ipv4/ip_gre.c:490
       erspan_xmit+0xa81/0x1670 net/ipv4/ip_gre.c:749
       __netdev_start_xmit include/linux/netdevice.h:5273 [inline]
       netdev_start_xmit include/linux/netdevice.h:5282 [inline]
       xmit_one net/core/dev.c:3866 [inline]
       dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3882
       sch_direct_xmit+0x251/0x4c0 net/sched/sch_generic.c:347
       __dev_xmit_skb net/core/dev.c:4182 [inline]
       __dev_queue_xmit+0x1538/0x3850 net/core/dev.c:4798
       dev_queue_xmit include/linux/netdevice.h:3381 [inline]
       alb_send_lp_vid+0x348/0x550 drivers/net/bonding/bond_alb.c:949
       alb_send_learning_packets+0x12c/0x300 drivers/net/bonding/bond_alb.c:1012
       bond_alb_monitor+0x3d5/0x17e0 drivers/net/bonding/bond_alb.c:1563
       process_one_work kernel/workqueue.c:3257 [inline]
       process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
       worker_thread+0xda6/0x1360 kernel/workqueue.c:3421
       kthread+0x726/0x8b0 kernel/kthread.c:463
       ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&qdisc_xmit_lock_key#4);
                               lock(&hsr->seqnr_lock);
                               lock(&qdisc_xmit_lock_key#4);
  lock(&hsr->seqnr_lock);

 *** DEADLOCK ***

11 locks held by kworker/u8:15/11209:
 #0: ffff88801fe8c948 ((wq_completion)bond4#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff88801fe8c948 ((wq_completion)bond4#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
 #1: ffffc900125a7bc0 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc900125a7bc0 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
 #2: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #2: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #2: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: bond_alb_monitor+0xf8/0x17e0 drivers/net/bonding/bond_alb.c:1546
 #3: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
 #3: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline]
 #3: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x3850 net/core/dev.c:4757
 #4: ffff88806ab15228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:361 [inline]
 #4: ffff88806ab15228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:202 [inline]
 #4: ffff88806ab15228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4169 [inline]
 #4: ffff88806ab15228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_queue_xmit+0x1002/0x3850 net/core/dev.c:4798
 #5: ffff88807e156558 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #5: ffff88807e156558 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4710 [inline]
 #5: ffff88807e156558 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:345
 #6: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #6: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #6: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: ip_output+0x5b/0x450 net/ipv4/ip_output.c:433
 #7: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #7: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #7: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x3d0/0xff0 net/ipv4/ip_output.c:230
 #8: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #8: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #8: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: arp_xmit+0x23/0x270 net/ipv4/arp.c:663
 #9: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline]
 #9: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline]
 #9: ffffffff8e55a3c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x3850 net/core/dev.c:4757
 #10: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #10: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #10: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229

stack backtrace:
CPU: 1 UID: 0 PID: 11209 Comm: kworker/u8:15 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: bond4 bond_alb_monitor
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043
 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
 check_prev_add kernel/locking/lockdep.c:3165 [inline]
 check_prevs_add kernel/locking/lockdep.c:3284 [inline]
 validate_chain kernel/locking/lockdep.c:3908 [inline]
 __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
 _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178
 spin_lock_bh include/linux/spinlock.h:356 [inline]
 hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235
 __netdev_start_xmit include/linux/netdevice.h:5273 [inline]
 netdev_start_xmit include/linux/netdevice.h:5282 [inline]
 xmit_one net/core/dev.c:3866 [inline]
 dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3882
 __dev_queue_xmit+0x168f/0x3850 net/core/dev.c:4832
 NF_HOOK+0x33a/0x3c0 include/linux/netfilter.h:-1
 arp_xmit+0x16c/0x270 net/ipv4/arp.c:665
 arp_solicit+0xbe0/0xe40 net/ipv4/arp.c:392
 neigh_probe net/core/neighbour.c:1097 [inline]
 __neigh_event_send+0xf05/0x14a0 net/core/neighbour.c:1270
 neigh_event_send_probe include/net/neighbour.h:480 [inline]
 neigh_event_send include/net/neighbour.h:486 [inline]
 neigh_resolve_output+0x198/0x750 net/core/neighbour.c:1578
 neigh_output include/net/neighbour.h:556 [inline]
 ip_finish_output2+0xbb6/0xff0 net/ipv4/ip_output.c:237
 NF_HOOK_COND include/linux/netfilter.h:307 [inline]
 ip_output+0x29f/0x450 net/ipv4/ip_output.c:438
 iptunnel_xmit+0x59f/0xa00 net/ipv4/ip_tunnel_core.c:84
 ip_tunnel_xmit+0x1f74/0x2730 net/ipv4/ip_tunnel.c:845
 __gre_xmit+0x19e/0x240 net/ipv4/ip_gre.c:490
 erspan_xmit+0xa81/0x1670 net/ipv4/ip_gre.c:749
 __netdev_start_xmit include/linux/netdevice.h:5273 [inline]
 netdev_start_xmit include/linux/netdevice.h:5282 [inline]
 xmit_one net/core/dev.c:3866 [inline]
 dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3882
 sch_direct_xmit+0x251/0x4c0 net/sched/sch_generic.c:347
 __dev_xmit_skb net/core/dev.c:4182 [inline]
 __dev_queue_xmit+0x1538/0x3850 net/core/dev.c:4798
 dev_queue_xmit include/linux/netdevice.h:3381 [inline]
 alb_send_lp_vid+0x348/0x550 drivers/net/bonding/bond_alb.c:949
 alb_send_learning_packets+0x12c/0x300 drivers/net/bonding/bond_alb.c:1012
 bond_alb_monitor+0x3d5/0x17e0 drivers/net/bonding/bond_alb.c:1563
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
 worker_thread+0xda6/0x1360 kernel/workqueue.c:3421
 kthread+0x726/0x8b0 kernel/kthread.c:463
 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
net_ratelimit: 74 callbacks suppressed
bond4: (slave ip6gretap1): link status up, enabling it in 0 ms
bond4: (slave ip6gretap1): failed to get link speed/duplex
bond4: (slave ip6gretap1): link status up, enabling it in 0 ms
bond4: (slave ip6gretap1): failed to get link speed/duplex
bond4: (slave ip6gretap1): link status up, enabling it in 0 ms
bond4: (slave ip6gretap1): failed to get link speed/duplex
bond4: (slave ip6gretap1): link status up, enabling it in 0 ms
bond4: (slave ip6gretap1): failed to get link speed/duplex