============================================ WARNING: possible recursive locking detected 6.12.0-syzkaller-05480-gfcc79e1714e8 #0 Not tainted -------------------------------------------- syz.1.2620/14236 is trying to acquire lock: ffff88805c446f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff88805c446f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: hsr_dev_xmit+0x18a/0x210 net/hsr/hsr_device.c:234 but task is already holding lock: ffff888062644f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] ffff888062644f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_hsr_supervision_frame+0x27c/0xcc0 net/hsr/hsr_device.c:317 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 8 locks held by syz.1.2620/14236: #0: ffffffff8fef1388 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fef1388 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fef1388 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dellink+0x394/0x8d0 net/core/rtnetlink.c:3504 #1: ffffc90000007c00 ((&hsr->announce_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x650 kernel/time/timer.c:1790 #2: ffffffff8eb3c860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #2: ffffffff8eb3c860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #2: ffffffff8eb3c860 (rcu_read_lock){....}-{1:3}, at: hsr_announce+0xaa/0x3a0 net/hsr/hsr_device.c:406 #3: ffff888062644f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #3: ffff888062644f30 (&hsr->seqnr_lock){+.-.}-{3:3}, at: send_hsr_supervision_frame+0x27c/0xcc0 net/hsr/hsr_device.c:317 #4: ffffffff8eb3c860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #4: ffffffff8eb3c860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #4: ffffffff8eb3c860 (rcu_read_lock){....}-{1:3}, at: hsr_forward_skb+0xb6/0x2ac0 net/hsr/hsr_forward.c:723 #5: ffffffff8eb3c8c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #5: ffffffff8eb3c8c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:901 [inline] #5: ffffffff8eb3c8c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2f4/0x3f50 net/core/dev.c:4359 #6: ffffffff8eb3c860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #6: ffffffff8eb3c860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #6: ffffffff8eb3c860 (rcu_read_lock){....}-{1:3}, at: br_dev_xmit+0x21d/0x1b40 net/bridge/br_device.c:50 #7: ffffffff8eb3c8c0 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #7: ffffffff8eb3c8c0 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:901 [inline] #7: ffffffff8eb3c8c0 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x2f4/0x3f50 net/core/dev.c:4359 stack backtrace: CPU: 0 UID: 0 PID: 14236 Comm: syz.1.2620 Not tainted 6.12.0-syzkaller-05480-gfcc79e1714e8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3037 check_deadlock kernel/locking/lockdep.c:3089 [inline] validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3891 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline] _raw_spin_lock_bh+0x35/0x50 kernel/locking/spinlock.c:178 spin_lock_bh include/linux/spinlock.h:356 [inline] hsr_dev_xmit+0x18a/0x210 net/hsr/hsr_device.c:234 __netdev_start_xmit include/linux/netdevice.h:5002 [inline] netdev_start_xmit include/linux/netdevice.h:5011 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x27a/0x7e0 net/core/dev.c:3606 __dev_queue_xmit+0x1b73/0x3f50 net/core/dev.c:4434 dev_queue_xmit include/linux/netdevice.h:3168 [inline] br_dev_queue_push_xmit+0x726/0x900 net/bridge/br_forward.c:53 NF_HOOK+0x3a7/0x460 include/linux/netfilter.h:314 br_forward_finish+0xd8/0x130 net/bridge/br_forward.c:66 NF_HOOK+0x3a7/0x460 include/linux/netfilter.h:314 __br_forward+0x489/0x660 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xb3/0x150 net/bridge/br_forward.c:190 br_flood+0x2e4/0x660 net/bridge/br_forward.c:236 br_dev_xmit+0x1202/0x1b40 __netdev_start_xmit include/linux/netdevice.h:5002 [inline] netdev_start_xmit include/linux/netdevice.h:5011 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x27a/0x7e0 net/core/dev.c:3606 __dev_queue_xmit+0x1b73/0x3f50 net/core/dev.c:4434 dev_queue_xmit include/linux/netdevice.h:3168 [inline] hsr_xmit net/hsr/hsr_forward.c:430 [inline] hsr_forward_do net/hsr/hsr_forward.c:571 [inline] hsr_forward_skb+0x171c/0x2ac0 net/hsr/hsr_forward.c:728 send_hsr_supervision_frame+0x63b/0xcc0 net/hsr/hsr_device.c:351 hsr_announce+0x1f8/0x3a0 net/hsr/hsr_device.c:408 call_timer_fn+0x18e/0x650 kernel/time/timer.c:1793 expire_timers kernel/time/timer.c:1844 [inline] __run_timers kernel/time/timer.c:2418 [inline] __run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2430 run_timer_base kernel/time/timer.c:2439 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2449 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:655 irq_exit_rcu+0x9/0x30 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:preempt_schedule_irq+0xf6/0x1c0 kernel/sched/core.c:7078 Code: 89 f5 49 c1 ed 03 eb 0d 48 f7 03 08 00 00 00 0f 84 8b 00 00 00 bf 01 00 00 00 e8 55 62 81 f5 e8 d0 ca ba f5 fb bf 01 00 00 00 85 ab ff ff 43 80 7c 3d 00 00 74 08 4c 89 f7 e8 b5 b3 1d f6 48 RSP: 0018:ffffc9001afdecc0 EFLAGS: 00000282 RAX: 03297ecf3116a200 RBX: 1ffff920035fbda0 RCX: ffffffff8171048a RDX: dffffc0000000000 RSI: ffffffff8c2ad300 RDI: 0000000000000001 RBP: ffffc9001afded80 R08: ffffffff9454688f R09: 1ffffffff28a8d11 R10: dffffc0000000000 R11: fffffbfff28a8d12 R12: 1ffff920035fbd98 R13: 1ffff920035fbd9c R14: ffffc9001afdece0 R15: dffffc0000000000 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:lockdep_unregister_key+0x56d/0x610 kernel/locking/lockdep.c:6593 Code: 4f 94 48 c7 c6 c0 e2 70 81 e8 3f 27 0a 00 e8 aa 3b 0a 00 e9 e5 fb ff ff e8 80 f0 68 0a 41 f7 c7 00 02 00 00 74 d0 fb 45 84 f6 <75> cf eb e0 90 0f 0b 90 45 31 f6 e9 62 ff ff ff 90 0f 0b 90 e9 a1 RSP: 0018:ffffc9001afdee40 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 1ffff920035fbdd0 RCX: ffffffff9a64d903 RDX: 0000000000000001 RSI: ffffffff8c2ae040 RDI: ffffffff8c820860 RBP: ffffc9001afdef18 R08: ffffffff944f8237 R09: 1ffffffff289f046 R10: dffffc0000000000 R11: fffffbfff289f047 R12: ffffc9001afdee80 R13: 1ffff920035fbdcc R14: 0000000000000000 R15: 0000000000000a07 __qdisc_destroy+0x165/0x410 net/sched/sch_generic.c:1085 netdev_for_each_tx_queue include/linux/netdevice.h:2562 [inline] dev_shutdown+0x9b/0x450 net/sched/sch_generic.c:1496 unregister_netdevice_many_notify+0x995/0x1da0 net/core/dev.c:11509 rtnl_delete_link net/core/rtnetlink.c:3470 [inline] rtnl_dellink+0x52b/0x8d0 net/core/rtnetlink.c:3512 rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6911 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2541 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1347 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1891 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:726 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583 ___sys_sendmsg net/socket.c:2637 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2669 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd23137e819 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:00007fd22f1d5038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fd231536080 RCX: 00007fd23137e819 RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000008 RBP: 00007fd2313f175e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fd231536080 R15: 00007ffc3428a848 ---------------- Code disassembly (best guess): 0: 89 f5 mov %esi,%ebp 2: 49 c1 ed 03 shr $0x3,%r13 6: eb 0d jmp 0x15 8: 48 f7 03 08 00 00 00 testq $0x8,(%rbx) f: 0f 84 8b 00 00 00 je 0xa0 15: bf 01 00 00 00 mov $0x1,%edi 1a: e8 55 62 81 f5 call 0xf5816274 1f: e8 d0 ca ba f5 call 0xf5bacaf4 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 85 ab ff ff call 0xffffabb4 <-- trapping instruction 2f: 43 80 7c 3d 00 00 cmpb $0x0,0x0(%r13,%r15,1) 35: 74 08 je 0x3f 37: 4c 89 f7 mov %r14,%rdi 3a: e8 b5 b3 1d f6 call 0xf61db3f4 3f: 48 rex.W