=============================
WARNING: suspicious RCU usage
6.9.0-rc6-syzkaller-01478-gcdc74c9d06e7 #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
2 locks held by syz-executor.2/17921:
 #0: ffffc90000a08c00 ((&p->forward_delay_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x650 kernel/time/timer.c:1790
 #1: ffff888012738cb8 (&br->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #1: ffff888012738cb8 (&br->lock){+.-.}-{2:2}, at: br_forward_delay_timer_expired+0x50/0x440 net/bridge/br_stp_timer.c:86
stack backtrace:
CPU: 1 PID: 17921 Comm: syz-executor.2 Not tainted 6.9.0-rc6-syzkaller-01478-gcdc74c9d06e7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 
 __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+0x176/0x440 net/bridge/br_stp_timer.c:88
 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
 
 
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194
Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 ae f7 6d f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00  53 a5 d8 f5 65 8b 05 f4 a6 76 74 85 c0 74 43 48 c7 04 24 0e 36
RSP: 0018:ffffc9000acd7640 EFLAGS: 00000206
RAX: ae39bd770393f100 RBX: 1ffff9200159aecc RCX: ffffffff94738603
RDX: dffffc0000000000 RSI: ffffffff8bcab900 RDI: 0000000000000001
RBP: ffffc9000acd76d0 R08: ffffffff8fa92bef R09: 1ffffffff1f5257d
R10: dffffc0000000000 R11: fffffbfff1f5257e R12: dffffc0000000000
R13: 1ffff9200159aec8 R14: ffffc9000acd7660 R15: 0000000000000246
 __debug_check_no_obj_freed lib/debugobjects.c:998 [inline]
 debug_check_no_obj_freed+0x561/0x580 lib/debugobjects.c:1019
 free_pages_prepare mm/page_alloc.c:1147 [inline]
 free_unref_page_prepare+0x322/0xab0 mm/page_alloc.c:2347
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2487
 __folio_put_large+0x168/0x1d0 mm/swap.c:132
 __folio_put+0x299/0x390 mm/swap.c:140
 folio_put include/linux/mm.h:1508 [inline]
 put_page include/linux/mm.h:1580 [inline]
 do_exit+0x1cd8/0x27e0 kernel/exit.c:917
 do_group_exit+0x207/0x2c0 kernel/exit.c:1027
 get_signal+0x16a1/0x1740 kernel/signal.c:2911
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x102/0x240 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f097bc7f8d4
Code: Unable to access opcode bytes at 0x7f097bc7f8aa.
RSP: 002b:00007f097ca68f60 EFLAGS: 00000246 ORIG_RAX: 000000000000002d
RAX: fffffffffffffe00 RBX: 00007f097ca69050 RCX: 00007f097bc7f8d4
RDX: 0000000000001000 RSI: 00007f097ca690a0 RDI: 0000000000000005
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005
R13: 00007f097ca68ff8 R14: 00007f097ca690a0 R15: 0000000000000000
 
bridge0: port 1(bridge_slave_0) entered learning state
ip6_tunnel: ip6gretap0 xmit: Local address not yet configured!
ip6_tunnel: ip6gretap0 xmit: Local address not yet configured!
ip6_tunnel: ip6gretap0 xmit: Local address not yet configured!
ip6_tunnel: ip6gretap0 xmit: Local address not yet configured!
ip6_tunnel: ip6gretap0 xmit: Local address not yet configured!
----------------
Code disassembly (best guess):
   0:	9c                   	pushf
   1:	8f 44 24 20          	pop    0x20(%rsp)
   5:	42 80 3c 23 00       	cmpb   $0x0,(%rbx,%r12,1)
   a:	74 08                	je     0x14
   c:	4c 89 f7             	mov    %r14,%rdi
   f:	e8 ae f7 6d f6       	call   0xf66df7c2
  14:	f6 44 24 21 02       	testb  $0x2,0x21(%rsp)
  19:	75 52                	jne    0x6d
  1b:	41 f7 c7 00 02 00 00 	test   $0x200,%r15d
  22:	74 01                	je     0x25
  24:	fb                   	sti
  25:	bf 01 00 00 00       	mov    $0x1,%edi
* 2a:	e8 53 a5 d8 f5       	call   0xf5d8a582 <-- trapping instruction
  2f:	65 8b 05 f4 a6 76 74 	mov    %gs:0x7476a6f4(%rip),%eax        # 0x7476a72a
  36:	85 c0                	test   %eax,%eax
  38:	74 43                	je     0x7d
  3a:	48                   	rex.W
  3b:	c7                   	.byte 0xc7
  3c:	04 24                	add    $0x24,%al
  3e:	0e                   	(bad)
  3f:	36                   	ss