=============================
WARNING: suspicious RCU usage
6.9.0-rc6-syzkaller-00053-g0106679839f7 #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 swapper/0/0:
#0: ffffc90000007cb0 ((&p->forward_delay_timer)){+.-.}-{0:0}, at: call_timer_fn+0x11a/0x610 kernel/time/timer.c:1790
#1: ffff88803e4d0cb8 (&br->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#1: ffff88803e4d0cb8 (&br->lock){+.-.}-{2:2}, at: br_forward_delay_timer_expired+0x4f/0x560 net/bridge/br_stp_timer.c:86
stack backtrace:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.9.0-rc6-syzkaller-00053-g0106679839f7 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:114
lockdep_rcu_suspicious+0x20b/0x3b0 kernel/locking/lockdep.c:6712
nbp_vlan_group net/bridge/br_private.h:1599 [inline]
br_mst_set_state+0x4cd/0x5e0 net/bridge/br_mst.c:105
br_set_state+0x542/0x880 net/bridge/br_stp.c:47
br_forward_delay_timer_expired+0x311/0x560 net/bridge/br_stp_timer.c:88
call_timer_fn+0x1a0/0x610 kernel/time/timer.c:1793
expire_timers kernel/time/timer.c:1844 [inline]
__run_timers+0x74b/0xaf0 kernel/time/timer.c:2418
__run_timer_base kernel/time/timer.c:2429 [inline]
__run_timer_base kernel/time/timer.c:2422 [inline]
run_timer_base+0x111/0x190 kernel/time/timer.c:2438
run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2448
__do_softirq+0x218/0x922 kernel/softirq.c:554
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu kernel/softirq.c:633 [inline]
irq_exit_rcu+0xb9/0x120 kernel/softirq.c:645
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
sysvec_apic_timer_interrupt+0x95/0xb0 arch/x86/kernel/apic/apic.c:1043
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline]
RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:72 [inline]
RIP: 0010:default_idle+0xf/0x20 arch/x86/kernel/process.c:743
Code: 4c 01 c7 4c 29 c2 e9 72 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d b3 f5 2a 00 fb f4 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90
RSP: 0018:ffffffff8d407e20 EFLAGS: 00000242
RAX: 000000000016b1a1 RBX: 0000000000000000 RCX: ffffffff8adb8c59
RDX: 0000000000000000 RSI: ffffffff8b0cae00 RDI: ffffffff8b6f55a0
RBP: fffffbfff1a92ae8 R08: 0000000000000001 R09: ffffed100d646fdd
R10: ffff88806b237eeb R11: 0000000000000000 R12: 0000000000000000
R13: ffffffff8d495740 R14: ffffffff8f9f4910 R15: 0000000000000000
default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x32c/0x3f0 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
rest_init+0x16b/0x2b0 init/main.c:739
start_kernel+0x3a3/0x490 init/main.c:1081
x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507
x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488
common_startup_64+0x13e/0x148
bridge0: port 2(bridge_slave_1) entered learning state
----------------
Code disassembly (best guess):
0: 4c 01 c7 add %r8,%rdi
3: 4c 29 c2 sub %r8,%rdx
6: e9 72 ff ff ff jmp 0xffffff7d
b: 90 nop
c: 90 nop
d: 90 nop
e: 90 nop
f: 90 nop
10: 90 nop
11: 90 nop
12: 90 nop
13: 90 nop
14: 90 nop
15: 90 nop
16: 90 nop
17: 90 nop
18: 90 nop
19: 90 nop
1a: 90 nop
1b: f3 0f 1e fa endbr64
1f: 66 90 xchg %ax,%ax
21: 0f 00 2d b3 f5 2a 00 verw 0x2af5b3(%rip) # 0x2af5db
28: fb sti
29: f4 hlt
* 2a: fa cli <-- trapping instruction
2b: c3 ret
2c: cc int3
2d: cc int3
2e: cc int3
2f: cc int3
30: 66 66 2e 0f 1f 84 00 data16 cs nopw 0x0(%rax,%rax,1)
37: 00 00 00 00
3b: 90 nop
3c: 90 nop
3d: 90 nop
3e: 90 nop
3f: 90 nop