============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz.3.2327/14214 is trying to acquire lock: ffff88807b264f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88807b264f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x237/0x360 net/hsr/hsr_device.c:235 but task is already holding lock: ffff88807b264f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88807b264f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_prp_supervision_frame+0x195/0x6c0 net/hsr/hsr_device.c:387 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 17 locks held by syz.3.2327/14214: #0: ffffffff8df92de8 (tracepoints_mutex){+.+.}-{4:4}, at: tracepoint_probe_register_prio_may_exist+0x43/0xa0 kernel/tracepoint.c:431 #1: ffffffff8ddd5530 (cpu_hotplug_lock){++++}-{0:0}, at: __static_call_update+0x8d/0x5d0 kernel/static_call_inline.c:139 #2: ffffffff8dff06e8 (static_call_mutex){+.+.}-{4:4}, at: static_call_lock kernel/static_call_inline.c:36 [inline] #2: ffffffff8dff06e8 (static_call_mutex){+.+.}-{4:4}, at: __static_call_update+0x9b/0x5d0 kernel/static_call_inline.c:140 #3: ffffffff8dde8928 (text_mutex){+.+.}-{4:4}, at: arch_static_call_transform+0x2d/0xc0 arch/x86/kernel/static_call.c:159 #4: ffffc90000a08be0 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xbe/0x5f0 kernel/time/timer.c:1744 #5: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #5: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #5: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: hsr_announce+0x83/0x360 net/hsr/hsr_device.c:416 #6: ffff88807b264f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #6: ffff88807b264f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_prp_supervision_frame+0x195/0x6c0 net/hsr/hsr_device.c:387 #7: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #7: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #7: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0x9e/0x2860 net/hsr/hsr_forward.c:728 #8: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #8: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline] #8: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50 net/core/dev.c:4688 #9: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #9: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #9: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: bond_start_xmit+0xf8/0x1a10 drivers/net/bonding/bond_main.c:5577 #10: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #10: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline] #10: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50 net/core/dev.c:4688 #11: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #11: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #11: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: geneve_xmit+0x128/0x2b70 drivers/net/geneve.c:1044 #12: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #12: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #12: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: ip6_output+0x126/0x550 net/ipv6/ip6_output.c:235 #13: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #13: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #13: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: ndisc_send_skb+0x1e4/0x1510 net/ipv6/ndisc.c:482 #14: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #14: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #14: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: ip6_output+0x126/0x550 net/ipv6/ip6_output.c:235 #15: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #15: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:918 [inline] #15: ffffffff8df3d6c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x27b/0x3b50 net/core/dev.c:4688 #16: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #16: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #16: ffffffff8df3d660 (rcu_read_lock){....}-{1:3}, at: hsr_dev_xmit+0x2d/0x360 net/hsr/hsr_device.c:229 stack backtrace: CPU: 1 UID: 0 PID: 14214 Comm: syz.3.2327 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_deadlock_bug+0x28b/0x2a0 kernel/locking/lockdep.c:3041 check_deadlock kernel/locking/lockdep.c:3093 [inline] validate_chain+0x1a3f/0x2140 kernel/locking/lockdep.c:3895 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 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:5248 [inline] netdev_start_xmit include/linux/netdevice.h:5257 [inline] xmit_one net/core/dev.c:3845 [inline] dev_hard_start_xmit+0x2d7/0x830 net/core/dev.c:3861 __dev_queue_xmit+0x1b8d/0x3b50 net/core/dev.c:4763 neigh_output include/net/neighbour.h:547 [inline] ip6_finish_output2+0xfb3/0x1480 net/ipv6/ip6_output.c:136 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247 NF_HOOK include/linux/netfilter.h:318 [inline] ndisc_send_skb+0xbce/0x1510 net/ipv6/ndisc.c:512 ndisc_send_ns net/ipv6/ndisc.c:670 [inline] ndisc_solicit+0x444/0x610 net/ipv6/ndisc.c:-1 neigh_probe net/core/neighbour.c:1098 [inline] __neigh_event_send+0xf70/0x1560 net/core/neighbour.c:1271 neigh_event_send_probe include/net/neighbour.h:471 [inline] neigh_event_send include/net/neighbour.h:477 [inline] neigh_resolve_output+0x198/0x750 net/core/neighbour.c:1579 neigh_output include/net/neighbour.h:547 [inline] ip6_finish_output2+0xfb3/0x1480 net/ipv6/ip6_output.c:136 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247 ip6tunnel_xmit include/net/ip6_tunnel.h:162 [inline] udp_tunnel6_xmit_skb+0x68d/0xb30 net/ipv6/ip6_udp_tunnel.c:112 geneve6_xmit_skb drivers/net/geneve.c:1016 [inline] geneve_xmit+0x1cc9/0x2b70 drivers/net/geneve.c:1047 __netdev_start_xmit include/linux/netdevice.h:5248 [inline] netdev_start_xmit include/linux/netdevice.h:5257 [inline] xmit_one net/core/dev.c:3845 [inline] dev_hard_start_xmit+0x2d7/0x830 net/core/dev.c:3861 sch_direct_xmit+0x241/0x4b0 net/sched/sch_generic.c:347 qdisc_restart net/sched/sch_generic.c:412 [inline] __qdisc_run+0xaa0/0x1540 net/sched/sch_generic.c:420 __dev_xmit_skb net/core/dev.c:4221 [inline] __dev_queue_xmit+0x1056/0x3b50 net/core/dev.c:4729 __bond_start_xmit include/linux/netdevice.h:-1 [inline] bond_start_xmit+0xdc7/0x1a10 drivers/net/bonding/bond_main.c:5579 __netdev_start_xmit include/linux/netdevice.h:5248 [inline] netdev_start_xmit include/linux/netdevice.h:5257 [inline] xmit_one net/core/dev.c:3845 [inline] dev_hard_start_xmit+0x2d7/0x830 net/core/dev.c:3861 __dev_queue_xmit+0x1b8d/0x3b50 net/core/dev.c:4763 dev_queue_xmit include/linux/netdevice.h:3365 [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 send_prp_supervision_frame+0x35b/0x6c0 net/hsr/hsr_device.c:402 hsr_announce+0x1d5/0x360 net/hsr/hsr_device.c:418 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:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 b6 73 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 6f 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 45 6f RSP: 0018:ffffc9001c07f580 EFLAGS: 00000283 RAX: ffffffff81b4974b RBX: 1ffff11017108441 RCX: 0000000000080000 RDX: ffffc9000c68a000 RSI: 00000000000099c6 RDI: 00000000000099c7 RBP: ffffc9001c07f700 R08: ffffffff8f7ce477 R09: 1ffffffff1ef9c8e R10: dffffc0000000000 R11: fffffbfff1ef9c8f R12: ffff8880b8842208 R13: dffffc0000000000 R14: ffff8880b893b240 R15: 0000000000000000 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2713 [inline] smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2923 __static_call_transform+0x4eb/0x750 arch/x86/kernel/static_call.c:111 arch_static_call_transform+0x98/0xc0 arch/x86/kernel/static_call.c:-1 __static_call_update+0xe4/0x5d0 kernel/static_call_inline.c:147 tracepoint_update_call kernel/tracepoint.c:271 [inline] tracepoint_add_func+0x91e/0xa10 kernel/tracepoint.c:312 tracepoint_probe_register_prio_may_exist+0x5f/0xa0 kernel/tracepoint.c:435 bpf_raw_tp_link_attach+0x4f0/0x6c0 kernel/bpf/syscall.c:4250 bpf_raw_tracepoint_open+0x1b2/0x220 kernel/bpf/syscall.c:4281 __sys_bpf+0x73e/0x860 kernel/bpf/syscall.c:6191 __do_sys_bpf kernel/bpf/syscall.c:6259 [inline] __se_sys_bpf kernel/bpf/syscall.c:6257 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6257 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f146d58f6c9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f146e4ad038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f146d7e5fa0 RCX: 00007f146d58f6c9 RDX: 0000000000000010 RSI: 0000200000000540 RDI: 0000000000000011 RBP: 00007f146d611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f146d7e6038 R14: 00007f146d7e5fa0 R15: 00007ffde3534278 ---------------- Code disassembly (best guess): 0: 45 8b 2c 24 mov (%r12),%r13d 4: 44 89 ee mov %r13d,%esi 7: 83 e6 01 and $0x1,%esi a: 31 ff xor %edi,%edi c: e8 b6 73 0b 00 call 0xb73c7 11: 41 83 e5 01 and $0x1,%r13d 15: 49 bd 00 00 00 00 00 movabs $0xdffffc0000000000,%r13 1c: fc ff df 1f: 75 07 jne 0x28 21: e8 61 6f 0b 00 call 0xb6f87 26: eb 38 jmp 0x60 28: f3 90 pause * 2a: 42 0f b6 04 2b movzbl (%rbx,%r13,1),%eax <-- trapping instruction 2f: 84 c0 test %al,%al 31: 75 11 jne 0x44 33: 41 f7 04 24 01 00 00 testl $0x1,(%r12) 3a: 00 3b: 74 1e je 0x5b 3d: e8 .byte 0xe8 3e: 45 6f rex.RB outsl %ds:(%rsi),(%dx)