=============================
WARNING: suspicious RCU usage
6.9.0-rc6-syzkaller-01518-g7824463aaea9 #0 Not tainted
-----------------------------
net/bridge/br_private.h:1599 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
7 locks held by kworker/u8:56/663:
 #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3242 [inline]
 #0: ffff888015089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3348
 #1: ffffc9000376fd00 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3243 [inline]
 #1: ffffc9000376fd00 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3348
 #2: ffffffff8e1cf550 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_enable+0x12/0x20 kernel/jump_label.c:217
 #3: ffffffff8e3e18e8 (jump_label_mutex){+.+.}-{3:3}, at: jump_label_lock kernel/jump_label.c:27 [inline]
 #3: ffffffff8e3e18e8 (jump_label_mutex){+.+.}-{3:3}, at: static_key_enable_cpuslocked+0xd7/0x260 kernel/jump_label.c:202
 #4: ffffffff8e1e4848 (text_mutex){+.+.}-{3:3}, at: arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:145
 #5: ffffc90000007c00 ((&p->forward_delay_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x650 kernel/time/timer.c:1790
 #6: ffff8880647dccb8 (&br->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #6: ffff8880647dccb8 (&br->lock){+.-.}-{2:2}, at: br_forward_delay_timer_expired+0x50/0x440 net/bridge/br_stp_timer.c:86

stack backtrace:
CPU: 0 PID: 663 Comm: kworker/u8:56 Not tainted 6.9.0-rc6-syzkaller-01518-g7824463aaea9 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: events_unbound toggle_allocation_gate
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 lockdep_rcu_suspicious+0x221/0x340 kernel/locking/lockdep.c:6712
 nbp_vlan_group net/bridge/br_private.h:1599 [inline]
 br_mst_set_state+0x1ea/0x650 net/bridge/br_mst.c:105
 br_set_state+0x28a/0x7b0 net/bridge/br_stp.c:47
 br_forward_delay_timer_expired+0x9a/0x440 net/bridge/br_stp_timer.c:92
 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:2429
 run_timer_base kernel/time/timer.c:2438 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2448
 __do_softirq+0x2c6/0x980 kernel/softirq.c:554
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu+0xf2/0x1c0 kernel/softirq.c:633
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:645
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline]
RIP: 0010:smp_call_function_many_cond+0x18a5/0x2a00 kernel/smp.c:855
Code: 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 c0 d6 0b 00 eb 38 f3 90 42 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 <74> 1e e8 a4 d6 0b 00 eb e4 44 89 e9 80 e1 07 80 c1 03 38 c1 7c e2
RSP: 0018:ffffc9000376f6e0 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 1ffff110172a8871 RCX: ffff88805ffc5a00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000376f8e0 R08: ffffffff818a53ab R09: 1ffffffff25e84a0
R10: dffffc0000000000 R11: fffffbfff25e84a1 R12: dffffc0000000000
R13: ffff8880b9544388 R14: ffff8880b943f7c0 R15: 0000000000000001
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:2086 [inline]
 text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2296
 text_poke_flush arch/x86/kernel/alternative.c:2487 [inline]
 text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2494
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:205
 static_key_enable+0x1a/0x20 kernel/jump_label.c:218
 toggle_allocation_gate+0xb5/0x250 mm/kfence/core.c:826
 process_one_work kernel/workqueue.c:3267 [inline]
 process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3348
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3429
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
bridge0: port 2(bridge_slave_1) entered forwarding state
----------------
Code disassembly (best guess):
   0:	41 83 e4 01          	and    $0x1,%r12d
   4:	49 bc 00 00 00 00 00 	movabs $0xdffffc0000000000,%r12
   b:	fc ff df
   e:	75 07                	jne    0x17
  10:	e8 c0 d6 0b 00       	call   0xbd6d5
  15:	eb 38                	jmp    0x4f
  17:	f3 90                	pause
  19:	42 0f b6 04 23       	movzbl (%rbx,%r12,1),%eax
  1e:	84 c0                	test   %al,%al
  20:	75 11                	jne    0x33
  22:	41 f7 45 00 01 00 00 	testl  $0x1,0x0(%r13)
  29:	00
* 2a:	74 1e                	je     0x4a <-- trapping instruction
  2c:	e8 a4 d6 0b 00       	call   0xbd6d5
  31:	eb e4                	jmp    0x17
  33:	44 89 e9             	mov    %r13d,%ecx
  36:	80 e1 07             	and    $0x7,%cl
  39:	80 c1 03             	add    $0x3,%cl
  3c:	38 c1                	cmp    %al,%cl
  3e:	7c e2                	jl     0x22