====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ kworker/u8:3/49 is trying to acquire lock: ffff88808c986f70 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:347 [inline] ffff88808c986f70 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235 but task is already holding lock: ffff88807ae6a158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline] ffff88807ae6a158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4713 [inline] ffff88807ae6a158 (&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:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:341 [inline] __netif_tx_lock include/linux/netdevice.h:4713 [inline] sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:4179 [inline] __dev_queue_xmit+0x1538/0x3850 net/core/dev.c:4795 dev_queue_xmit include/linux/netdevice.h:3384 [inline] hsr_xmit net/hsr/hsr_forward.c:440 [inline] hsr_forward_do net/hsr/hsr_forward.c:581 [inline] hsr_forward_skb+0x157b/0x2860 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 kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 hrtimer_nanosleep+0x18b/0x390 kernel/time/hrtimer.c:2171 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1391 [inline] __se_sys_clock_nanosleep+0x35b/0x3b0 kernel/time/posix-timers.c:1368 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 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:150 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:347 [inline] hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235 __netdev_start_xmit include/linux/netdevice.h:5275 [inline] netdev_start_xmit include/linux/netdevice.h:5284 [inline] xmit_one net/core/dev.c:3864 [inline] dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3880 __dev_queue_xmit+0x168f/0x3850 net/core/dev.c:4829 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:1096 [inline] __neigh_event_send+0xf05/0x14a0 net/core/neighbour.c:1276 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:1603 neigh_output include/net/neighbour.h:556 [inline] ip_finish_output2+0xca9/0x1070 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+0x193a/0x1f20 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:5275 [inline] netdev_start_xmit include/linux/netdevice.h:5284 [inline] xmit_one net/core/dev.c:3864 [inline] dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3880 sch_direct_xmit+0x251/0x4c0 net/sched/sch_generic.c:347 __dev_xmit_skb net/core/dev.c:4179 [inline] __dev_queue_xmit+0x1538/0x3850 net/core/dev.c:4795 dev_queue_xmit include/linux/netdevice.h:3384 [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:3275 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 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(&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/u8:3/49: #0: ffff88805a6b4148 ((wq_completion)bond1#7){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88805a6b4148 ((wq_completion)bond1#7){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3358 #1: ffffc90000ba7c40 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90000ba7c40 ((work_completion)(&(&bond->alb_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3358 #2: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #2: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #2: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: bond_alb_monitor+0xf8/0x17e0 drivers/net/bonding/bond_alb.c:1546 #3: ffffffff8e75e100 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #3: ffffffff8e75e100 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:903 [inline] #3: ffffffff8e75e100 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x3850 net/core/dev.c:4754 #4: ffff88807b69e228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: spin_trylock include/linux/spinlock.h:353 [inline] #4: ffff88807b69e228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: qdisc_run_begin include/net/sch_generic.h:202 [inline] #4: ffff88807b69e228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4166 [inline] #4: ffff88807b69e228 (dev->qdisc_tx_busylock ?: &qdisc_tx_busylock#5){+...}-{3:3}, at: __dev_queue_xmit+0x1002/0x3850 net/core/dev.c:4795 #5: ffff88807ae6a158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline] #5: ffff88807ae6a158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: __netif_tx_lock include/linux/netdevice.h:4713 [inline] #5: ffff88807ae6a158 (&qdisc_xmit_lock_key#4){+.-.}-{3:3}, at: sch_direct_xmit+0x15f/0x4c0 net/sched/sch_generic.c:345 #6: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #6: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #6: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: ip_output+0x5b/0x450 net/ipv4/ip_output.c:433 #7: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #7: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #7: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x3c2/0x1070 net/ipv4/ip_output.c:230 #8: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #8: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #8: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: arp_xmit+0x23/0x270 net/ipv4/arp.c:663 #9: ffffffff8e75e100 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #9: ffffffff8e75e100 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:903 [inline] #9: ffffffff8e75e100 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x274/0x3850 net/core/dev.c:4754 #10: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #10: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #10: ffffffff8e75e0a0 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229 stack backtrace: CPU: 0 UID: 0 PID: 49 Comm: kworker/u8:3 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: bond1 bond_alb_monitor Call Trace: 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:150 [inline] _raw_spin_lock_bh+0x36/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:347 [inline] hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235 __netdev_start_xmit include/linux/netdevice.h:5275 [inline] netdev_start_xmit include/linux/netdevice.h:5284 [inline] xmit_one net/core/dev.c:3864 [inline] dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3880 __dev_queue_xmit+0x168f/0x3850 net/core/dev.c:4829 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:1096 [inline] __neigh_event_send+0xf05/0x14a0 net/core/neighbour.c:1276 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:1603 neigh_output include/net/neighbour.h:556 [inline] ip_finish_output2+0xca9/0x1070 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+0x193a/0x1f20 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:5275 [inline] netdev_start_xmit include/linux/netdevice.h:5284 [inline] xmit_one net/core/dev.c:3864 [inline] dev_hard_start_xmit+0x2cd/0x7f0 net/core/dev.c:3880 sch_direct_xmit+0x251/0x4c0 net/sched/sch_generic.c:347 __dev_xmit_skb net/core/dev.c:4179 [inline] __dev_queue_xmit+0x1538/0x3850 net/core/dev.c:4795 dev_queue_xmit include/linux/netdevice.h:3384 [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:3275 [inline] process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245