============================================ WARNING: possible recursive locking detected 6.14.0-syzkaller-13189-ge48e99b6edf4 #0 Not tainted -------------------------------------------- swapper/2/0 is trying to acquire lock: ffff88802a922f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88802a922f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x1bc/0x280 net/hsr/hsr_device.c:234 but task is already holding lock: ffff888050ba0f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888050ba0f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x1bc/0x280 net/hsr/hsr_device.c:234 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 10 locks held by swapper/2/0: #0: ffffc90000648ca8 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0x117/0x620 kernel/time/timer.c:1786 #1: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #1: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #1: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x1ab/0x1e40 net/ipv6/ndisc.c:484 #2: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #2: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: ip6_finish_output2+0x39d/0x2020 net/ipv6/ip6_output.c:126 #3: ffffffff8e3c1520 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #3: ffffffff8e3c1520 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #3: ffffffff8e3c1520 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x276/0x43e0 net/core/dev.c:4558 #4: ffff888050ba0f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #4: ffff888050ba0f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x1bc/0x280 net/hsr/hsr_device.c:234 #5: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #5: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #5: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0xa6/0x2910 net/hsr/hsr_forward.c:728 #6: ffffffff8e3c1520 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #6: ffffffff8e3c1520 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #6: ffffffff8e3c1520 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x276/0x43e0 net/core/dev.c:4558 #7: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e3c1580 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x18d/0x1880 net/bridge/br_device.c:52 #8: ffffffff8e3c1520 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #8: ffffffff8e3c1520 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #8: ffffffff8e3c1520 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x276/0x43e0 net/core/dev.c:4558 #9: ffffffff8e3c1520 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #9: ffffffff8e3c1520 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #9: ffffffff8e3c1520 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x276/0x43e0 net/core/dev.c:4558 stack backtrace: CPU: 2 UID: 0 PID: 0 Comm: swapper/2 Not tainted 6.14.0-syzkaller-13189-ge48e99b6edf4 #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 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_deadlock_bug+0x1e9/0x240 kernel/locking/lockdep.c:3042 check_deadlock kernel/locking/lockdep.c:3094 [inline] validate_chain kernel/locking/lockdep.c:3896 [inline] __lock_acquire+0xff7/0x1ba0 kernel/locking/lockdep.c:5235 lock_acquire kernel/locking/lockdep.c:5866 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x33/0x40 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] hsr_dev_xmit+0x1bc/0x280 net/hsr/hsr_device.c:234 __netdev_start_xmit include/linux/netdevice.h:5201 [inline] netdev_start_xmit include/linux/netdevice.h:5210 [inline] xmit_one net/core/dev.c:3780 [inline] dev_hard_start_xmit+0x93/0x740 net/core/dev.c:3796 __dev_queue_xmit+0x7eb/0x43e0 net/core/dev.c:4633 dev_queue_xmit include/linux/netdevice.h:3350 [inline] vlan_dev_hard_start_xmit+0x3af/0x5d0 net/8021q/vlan_dev.c:126 __netdev_start_xmit include/linux/netdevice.h:5201 [inline] netdev_start_xmit include/linux/netdevice.h:5210 [inline] xmit_one net/core/dev.c:3780 [inline] dev_hard_start_xmit+0x93/0x740 net/core/dev.c:3796 __dev_queue_xmit+0x7eb/0x43e0 net/core/dev.c:4633 dev_queue_xmit include/linux/netdevice.h:3350 [inline] br_dev_queue_push_xmit+0x272/0x8a0 net/bridge/br_forward.c:53 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] br_forward_finish+0xf5/0x130 net/bridge/br_forward.c:66 NF_HOOK include/linux/netfilter.h:314 [inline] NF_HOOK include/linux/netfilter.h:308 [inline] __br_forward+0x1e5/0x5b0 net/bridge/br_forward.c:115 br_flood+0x4c4/0x650 net/bridge/br_forward.c:251 br_dev_xmit+0xf70/0x1880 net/bridge/br_device.c:108 __netdev_start_xmit include/linux/netdevice.h:5201 [inline] netdev_start_xmit include/linux/netdevice.h:5210 [inline] xmit_one net/core/dev.c:3780 [inline] dev_hard_start_xmit+0x93/0x740 net/core/dev.c:3796 __dev_queue_xmit+0x7eb/0x43e0 net/core/dev.c:4633 dev_queue_xmit include/linux/netdevice.h:3350 [inline] hsr_xmit net/hsr/hsr_forward.c:430 [inline] hsr_forward_do net/hsr/hsr_forward.c:571 [inline] hsr_forward_skb+0xcd3/0x2910 net/hsr/hsr_forward.c:733 hsr_dev_xmit+0x1c7/0x280 net/hsr/hsr_device.c:235 __netdev_start_xmit include/linux/netdevice.h:5201 [inline] netdev_start_xmit include/linux/netdevice.h:5210 [inline] xmit_one net/core/dev.c:3780 [inline] dev_hard_start_xmit+0x93/0x740 net/core/dev.c:3796 __dev_queue_xmit+0x7eb/0x43e0 net/core/dev.c:4633 dev_queue_xmit include/linux/netdevice.h:3350 [inline] neigh_connected_output+0x3da/0x620 net/core/neighbour.c:1541 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:303 [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:314 [inline] ndisc_send_skb+0xa91/0x1e40 net/ipv6/ndisc.c:513 ndisc_send_rs+0x129/0x670 net/ipv6/ndisc.c:723 addrconf_rs_timer+0x40d/0x840 net/ipv6/addrconf.c:4033 call_timer_fn+0x197/0x620 kernel/time/timer.c:1789 expire_timers kernel/time/timer.c:1840 [inline] __run_timers+0x6ef/0x960 kernel/time/timer.c:2414 __run_timer_base kernel/time/timer.c:2426 [inline] __run_timer_base kernel/time/timer.c:2418 [inline] run_timer_base+0x114/0x190 kernel/time/timer.c:2435 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2445 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:81 Code: e5 5d 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d f3 1c 18 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000187df8 EFLAGS: 00000286 RAX: 0000000000513109 RBX: 0000000000000002 RCX: ffffffff8b71d419 RDX: 0000000000000000 RSI: ffffffff8dbedd7b RDI: ffffffff8bf46000 RBP: ffffed1003ad2910 R08: 0000000000000001 R09: ffffed100d4c65bd R10: ffff88806a632deb R11: 0000000000000000 R12: 0000000000000002 R13: ffff88801d694880 R14: ffffffff90864110 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:748 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148 IPVS: rr: UDP 224.0.0.2:0 - no destination available IPVS: rr: UDP 224.0.0.2:0 - no destination available IPVS: rr: UDP 224.0.0.2:0 - no destination available IPVS: rr: UDP 224.0.0.2:0 - no destination available IPVS: rr: UDP 224.0.0.2:0 - no destination available IPVS: rr: UDP 224.0.0.2:0 - no destination available IPVS: rr: UDP 224.0.0.2:0 - no destination available IPVS: rr: UDP 224.0.0.2:0 - no destination available ---------------- Code disassembly (best guess): 0: e5 5d in $0x5d,%eax 2: 02 c3 add %bl,%al 4: cc int3 5: cc int3 6: cc int3 7: cc int3 8: 0f 1f 00 nopl (%rax) b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: f3 0f 1e fa endbr64 1f: eb 07 jmp 0x28 21: 0f 00 2d f3 1c 18 00 verw 0x181cf3(%rip) # 0x181d1b 28: fb sti 29: f4 hlt * 2a: c3 ret <-- trapping instruction 2b: cc int3 2c: cc int3 2d: cc int3 2e: cc int3 2f: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 36: 00 00 00 39: 66 90 xchg %ax,%ax 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop