============================================ WARNING: possible recursive locking detected 5.15.178-syzkaller #0 Not tainted -------------------------------------------- syz.1.710/6111 is trying to acquire lock: ffff0000ce736d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline] ffff0000ce736d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: hsr_dev_xmit+0xf8/0x1d0 net/hsr/hsr_device.c:222 but task is already holding lock: ffff0000da0a8d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline] ffff0000da0a8d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: hsr_dev_xmit+0xf8/0x1d0 net/hsr/hsr_device.c:222 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&hsr->seqnr_lock); lock(&hsr->seqnr_lock); *** DEADLOCK *** May be due to missing lock nesting notation 11 locks held by syz.1.710/6111: #0: ffff800008007ba0 ((&ndev->rs_timer)){+.-.}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:45 [inline] #0: ffff800008007ba0 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0xd0/0x8f0 kernel/time/timer.c:1441 #1: ffff800014d42360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:311 #2: ffff800014d423c0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:311 #3: ffff800014d423c0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:311 #4: ffff0000da0a8d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline] #4: ffff0000da0a8d88 (&hsr->seqnr_lock){+.-.}-{2:2}, at: hsr_dev_xmit+0xf8/0x1d0 net/hsr/hsr_device.c:222 #5: ffff800014d42360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:311 #6: ffff800014d423c0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:311 #7: ffff800014d42360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:311 #8: ffff800014d423c0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:311 #9: ffff800014d42360 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x10/0x4c include/linux/rcupdate.h:311 #10: ffff800014d423c0 (rcu_read_lock_bh){....}-{1:2}, at: rcu_lock_acquire+0x18/0x54 include/linux/rcupdate.h:311 stack backtrace: CPU: 0 PID: 6111 Comm: syz.1.710 Not tainted 5.15.178-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call trace: dump_backtrace+0x0/0x530 arch/arm64/kernel/stacktrace.c:152 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 __lock_acquire+0x62bc/0x7638 kernel/locking/lockdep.c:5012 lock_acquire+0x240/0x77c kernel/locking/lockdep.c:5623 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x124/0x1c4 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:368 [inline] hsr_dev_xmit+0xf8/0x1d0 net/hsr/hsr_device.c:222 __netdev_start_xmit include/linux/netdevice.h:5019 [inline] netdev_start_xmit include/linux/netdevice.h:5033 [inline] xmit_one net/core/dev.c:3617 [inline] dev_hard_start_xmit+0x2bc/0x92c net/core/dev.c:3633 __dev_queue_xmit+0x1378/0x2ac8 net/core/dev.c:4256 dev_queue_xmit+0x24/0x34 net/core/dev.c:4289 br_dev_queue_push_xmit+0x56c/0x70c net/bridge/br_forward.c:53 NF_HOOK+0x358/0x404 include/linux/netfilter.h:302 br_forward_finish+0x7c/0x90 net/bridge/br_forward.c:66 NF_HOOK+0x358/0x404 include/linux/netfilter.h:302 __br_forward+0x2f0/0x458 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xc8/0x188 net/bridge/br_forward.c:189 br_flood+0x28c/0x41c net/bridge/br_forward.c:231 br_dev_xmit+0xd04/0x1270 __netdev_start_xmit include/linux/netdevice.h:5019 [inline] netdev_start_xmit include/linux/netdevice.h:5033 [inline] xmit_one net/core/dev.c:3617 [inline] dev_hard_start_xmit+0x2bc/0x92c net/core/dev.c:3633 __dev_queue_xmit+0x1378/0x2ac8 net/core/dev.c:4256 dev_queue_xmit+0x24/0x34 net/core/dev.c:4289 bond_start_xmit+0xdb0/0x1550 drivers/net/bonding/bond_main.c:5164 __netdev_start_xmit include/linux/netdevice.h:5019 [inline] netdev_start_xmit include/linux/netdevice.h:5033 [inline] xmit_one net/core/dev.c:3617 [inline] dev_hard_start_xmit+0x2bc/0x92c net/core/dev.c:3633 __dev_queue_xmit+0x1378/0x2ac8 net/core/dev.c:4256 dev_queue_xmit+0x24/0x34 net/core/dev.c:4289 hsr_xmit net/hsr/hsr_forward.c:338 [inline] hsr_forward_do net/hsr/hsr_forward.c:429 [inline] hsr_forward_skb+0xecc/0x161c net/hsr/hsr_forward.c:579 hsr_dev_xmit+0x104/0x1d0 net/hsr/hsr_device.c:223 __netdev_start_xmit include/linux/netdevice.h:5019 [inline] netdev_start_xmit include/linux/netdevice.h:5033 [inline] xmit_one net/core/dev.c:3617 [inline] dev_hard_start_xmit+0x2bc/0x92c net/core/dev.c:3633 __dev_queue_xmit+0x1378/0x2ac8 net/core/dev.c:4256 dev_queue_xmit+0x24/0x34 net/core/dev.c:4289 neigh_connected_output+0x334/0x378 net/core/neighbour.c:1533 neigh_output include/net/neighbour.h:509 [inline] ip6_finish_output2+0x1360/0x1cec net/ipv6/ip6_output.c:130 __ip6_finish_output+0x580/0x6ec net/ipv6/ip6_output.c:201 ip6_finish_output+0x40/0x218 net/ipv6/ip6_output.c:211 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip6_output+0x274/0x594 net/ipv6/ip6_output.c:234 dst_output include/net/dst.h:443 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ndisc_send_skb+0xbf8/0x1788 net/ipv6/ndisc.c:511 ndisc_send_rs+0x494/0x5fc net/ipv6/ndisc.c:705 addrconf_rs_timer+0x308/0x5a8 net/ipv6/addrconf.c:3959 call_timer_fn+0x19c/0x8f0 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x554/0x718 kernel/time/timer.c:1767 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1780 handle_softirqs+0x384/0xdbc kernel/softirq.c:558 __do_softirq kernel/softirq.c:592 [inline] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] invoke_softirq kernel/softirq.c:439 [inline] __irq_exit_rcu+0x268/0x4d8 kernel/softirq.c:641 irq_exit+0x14/0x88 kernel/softirq.c:665 handle_domain_irq+0xf4/0x178 kernel/irq/irqdesc.c:711 gic_handle_irq+0x78/0x1c8 drivers/irqchip/irq-gic-v3.c:765 call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:899 do_interrupt_handler+0x74/0x94 arch/arm64/kernel/entry-common.c:267 el1_interrupt+0x30/0x58 arch/arm64/kernel/entry-common.c:454 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:522 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:122 [inline] lock_release+0x504/0xa1c kernel/locking/lockdep.c:5646 __might_fault+0xf4/0x128 mm/memory.c:5355 ____sys_recvmsg+0x2c4/0x720 net/socket.c:2668 ___sys_recvmsg+0x240/0x2cc net/socket.c:2697 do_recvmmsg+0x310/0x9a4 net/socket.c:2791 __sys_recvmmsg net/socket.c:2870 [inline] __do_sys_recvmmsg net/socket.c:2893 [inline] __se_sys_recvmmsg net/socket.c:2886 [inline] __arm64_sys_recvmmsg+0x180/0x23c net/socket.c:2886 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181 el0_svc+0x7c/0x1f0 arch/arm64/kernel/entry-common.c:608 el0t_64_sync_handler+0x84/0xe4 arch/arm64/kernel/entry-common.c:626 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584