============================================ WARNING: possible recursive locking detected 6.16.0-rc6-syzkaller-01562-gd61f6cb6f6ef #0 Not tainted -------------------------------------------- syz.0.1250/9748 is trying to acquire lock: ffff88802479ef30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88802479ef30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x19a/0x220 net/hsr/hsr_device.c:234 but task is already holding lock: ffff8880291c4f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff8880291c4f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x19a/0x220 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 11 locks held by syz.0.1250/9748: #0: ffffc90000a08be0 ((&ndev->rs_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbe/0x5f0 kernel/time/timer.c:1744 #1: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #1: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #1: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x20c/0x1440 net/ipv6/ndisc.c:482 #2: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #2: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: ip6_finish_output2+0x701/0x16a0 net/ipv6/ip6_output.c:126 #3: ffffffff8e13f140 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #3: ffffffff8e13f140 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #3: ffffffff8e13f140 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50 net/core/dev.c:4638 #4: ffff8880291c4f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #4: ffff8880291c4f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x19a/0x220 net/hsr/hsr_device.c:234 #5: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #5: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #5: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0x9e/0x2860 net/hsr/hsr_forward.c:728 #6: ffffffff8e13f140 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #6: ffffffff8e13f140 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #6: ffffffff8e13f140 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50 net/core/dev.c:4638 #7: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #7: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: bond_start_xmit+0xf8/0x1a10 drivers/net/bonding/bond_main.c:5675 #8: ffffffff8e13f140 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #8: ffffffff8e13f140 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #8: ffffffff8e13f140 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50 net/core/dev.c:4638 #9: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #9: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #9: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x185/0x1840 net/bridge/br_device.c:52 #10: ffffffff8e13f140 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #10: ffffffff8e13f140 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:892 [inline] #10: ffffffff8e13f140 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50 net/core/dev.c:4638 stack backtrace: CPU: 1 UID: 0 PID: 9748 Comm: syz.0.1250 Not tainted 6.16.0-rc6-syzkaller-01562-gd61f6cb6f6ef #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3044 check_deadlock kernel/locking/lockdep.c:3096 [inline] validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3898 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __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+0x19a/0x220 net/hsr/hsr_device.c:234 __netdev_start_xmit include/linux/netdevice.h:5218 [inline] netdev_start_xmit include/linux/netdevice.h:5227 [inline] xmit_one net/core/dev.c:3827 [inline] dev_hard_start_xmit+0x2d4/0x830 net/core/dev.c:3843 __dev_queue_xmit+0x1b8d/0x3b50 net/core/dev.c:4713 dev_queue_xmit include/linux/netdevice.h:3357 [inline] br_dev_queue_push_xmit+0x6c5/0x890 net/bridge/br_forward.c:53 NF_HOOK+0x31d/0x3c0 include/linux/netfilter.h:317 br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66 NF_HOOK+0x31d/0x3c0 include/linux/netfilter.h:317 __br_forward+0x41e/0x600 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xb5/0x160 net/bridge/br_forward.c:190 br_flood+0x31a/0x6a0 net/bridge/br_forward.c:237 br_dev_xmit+0x11b3/0x1840 net/bridge/br_device.c:108 __netdev_start_xmit include/linux/netdevice.h:5218 [inline] netdev_start_xmit include/linux/netdevice.h:5227 [inline] xmit_one net/core/dev.c:3827 [inline] dev_hard_start_xmit+0x2d4/0x830 net/core/dev.c:3843 __dev_queue_xmit+0x1b8d/0x3b50 net/core/dev.c:4713 __bond_start_xmit include/linux/netdevice.h:-1 [inline] bond_start_xmit+0xdc7/0x1a10 drivers/net/bonding/bond_main.c:5677 __netdev_start_xmit include/linux/netdevice.h:5218 [inline] netdev_start_xmit include/linux/netdevice.h:5227 [inline] xmit_one net/core/dev.c:3827 [inline] dev_hard_start_xmit+0x2d4/0x830 net/core/dev.c:3843 __dev_queue_xmit+0x1b8d/0x3b50 net/core/dev.c:4713 dev_queue_xmit include/linux/netdevice.h:3357 [inline] hsr_xmit net/hsr/hsr_forward.c:430 [inline] hsr_forward_do net/hsr/hsr_forward.c:571 [inline] hsr_forward_skb+0x158b/0x2860 net/hsr/hsr_forward.c:733 hsr_dev_xmit+0x1a5/0x220 net/hsr/hsr_device.c:235 __netdev_start_xmit include/linux/netdevice.h:5218 [inline] netdev_start_xmit include/linux/netdevice.h:5227 [inline] xmit_one net/core/dev.c:3827 [inline] dev_hard_start_xmit+0x2d4/0x830 net/core/dev.c:3843 __dev_queue_xmit+0x1b8d/0x3b50 net/core/dev.c:4713 neigh_output include/net/neighbour.h:547 [inline] ip6_finish_output2+0x11fb/0x16a0 net/ipv6/ip6_output.c:141 NF_HOOK include/linux/netfilter.h:317 [inline] ndisc_send_skb+0xb54/0x1440 net/ipv6/ndisc.c:512 addrconf_rs_timer+0x369/0x670 net/ipv6/addrconf.c:4032 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch+0x26b/0x950 kernel/sched/core.c:5265 Code: 0f 84 3c 01 00 00 48 85 db 0f 85 63 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 0f 2a e0 09 e8 1a bb 35 00 fb 4c 8b 65 c0 <49> 8d bc 24 18 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0018:ffffc90003427938 EFLAGS: 00000282 RAX: 7fe554fffa69e700 RBX: 0000000000000000 RCX: 7fe554fffa69e700 RDX: 0000000000000000 RSI: ffffffff8d99e93e RDI: ffffffff8be28c40 RBP: ffffc90003427990 R08: ffffffff8fa22af7 R09: 1ffffffff1f4455e R10: dffffc0000000000 R11: fffffbfff1f4455f R12: ffff88802792bc00 R13: dffffc0000000000 R14: ffff88801d2f5a00 R15: ffff8880b873ab58 context_switch kernel/sched/core.c:5400 [inline] __schedule+0x16fd/0x4d00 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 do_nanosleep+0x1c7/0x600 kernel/time/hrtimer.c:2100 hrtimer_nanosleep+0x169/0x360 kernel/time/hrtimer.c:2147 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1399 [inline] __se_sys_clock_nanosleep+0x2ee/0x380 kernel/time/posix-timers.c:1376 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f410d9c11e5 Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 54 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f 55 ff ff 48 8b 04 24 48 83 c4 28 f7 d8 RSP: 002b:00007ffe3058cfa0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 00007f410dbb5fa0 RCX: 00007f410d9c11e5 RDX: 00007ffe3058cfe0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f410dbb7ba0 R08: 0000000000000000 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000293 R12: 00000000000383b7 R13: 00007ffe3058d100 R14: ffffffffffffffff R15: 00007ffe3058d120 ---------------- Code disassembly (best guess): 0: 0f 84 3c 01 00 00 je 0x142 6: 48 85 db test %rbx,%rbx 9: 0f 85 63 01 00 00 jne 0x172 f: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 14: 4c 8b 75 d0 mov -0x30(%rbp),%r14 18: 4c 89 e7 mov %r12,%rdi 1b: e8 0f 2a e0 09 call 0x9e02a2f 20: e8 1a bb 35 00 call 0x35bb3f 25: fb sti 26: 4c 8b 65 c0 mov -0x40(%rbp),%r12 * 2a: 49 8d bc 24 18 16 00 lea 0x1618(%r12),%rdi <-- trapping instruction 31: 00 32: 48 89 f8 mov %rdi,%rax 35: 48 c1 e8 03 shr $0x3,%rax 39: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax 3e: 84 c0 test %al,%al