=============================
WARNING: suspicious RCU usage
6.10.0-rc2-syzkaller-00249-gbe27b8965297 #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
3 locks held by syz-executor.4/6527:
#0: ffffc90000a18c00 ((&p->forward_delay_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x650 kernel/time/timer.c:1789
#1: ffff888063ed0cb8 (&br->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#1: ffff888063ed0cb8 (&br->lock){+.-.}-{2:2}, at: br_forward_delay_timer_expired+0x50/0x440 net/bridge/br_stp_timer.c:86
#2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
#2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
#2: ffffffff8e333fa0 (rcu_read_lock){....}-{1:2}, at: br_mst_set_state+0x171/0x7a0 net/bridge/br_mst.c:105
stack backtrace:
CPU: 1 PID: 6527 Comm: syz-executor.4 Not tainted 6.10.0-rc2-syzkaller-00249-gbe27b8965297 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
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+0x29e/0x7a0 net/bridge/br_mst.c:106
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:1792
expire_timers kernel/time/timer.c:1843 [inline]
__run_timers kernel/time/timer.c:2417 [inline]
__run_timer_base+0x66a/0x8e0 kernel/time/timer.c:2428
run_timer_base kernel/time/timer.c:2437 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2447
handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
__do_softirq kernel/softirq.c:588 [inline]
invoke_softirq kernel/softirq.c:428 [inline]
__irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
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:finish_task_switch+0x1ea/0x870 kernel/sched/core.c:5282
Code: c9 50 e8 99 c9 0b 00 48 83 c4 08 4c 89 f7 e8 cd 38 00 00 0f 1f 44 00 00 4c 89 f7 e8 60 c7 2a 0a e8 5b f8 36 00 fb 48 8b 5d c0 <48> 8d bb f8 15 00 00 48 89 f8 48 c1 e8 03 49 be 00 00 00 00 00 fc
RSP: 0018:ffffc900141df988 EFLAGS: 00000282
RAX: c48443b4343f6100 RBX: ffff88805e1a5a00 RCX: ffffffff947a3603
RDX: dffffc0000000000 RSI: ffffffff8bcabb80 RDI: ffffffff8c1ff380
RBP: ffffc900141df9d0 R08: ffffffff8fad50af R09: 1ffffffff1f5aa15
R10: dffffc0000000000 R11: fffffbfff1f5aa16 R12: 1ffff110172a7ea7
R13: dffffc0000000000 R14: ffff8880b953e7c0 R15: ffff8880b953f538
context_switch kernel/sched/core.c:5411 [inline]
__schedule+0x17f0/0x4a20 kernel/sched/core.c:6745
__schedule_loop kernel/sched/core.c:6822 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6837
do_nanosleep+0x197/0x600 kernel/time/hrtimer.c:2028
hrtimer_nanosleep+0x227/0x470 kernel/time/hrtimer.c:2081
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1396 [inline]
__se_sys_clock_nanosleep+0x32b/0x3c0 kernel/time/posix-timers.c:1373
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: 0033:0x7f76cdca8335
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 b9 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f ba ff ff 48 8b 04 24 48 83 c4 28 f7 d8
----------------
Code disassembly (best guess):
0: c9 leave
1: 50 push %rax
2: e8 99 c9 0b 00 call 0xbc9a0
7: 48 83 c4 08 add $0x8,%rsp
b: 4c 89 f7 mov %r14,%rdi
e: e8 cd 38 00 00 call 0x38e0
13: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
18: 4c 89 f7 mov %r14,%rdi
1b: e8 60 c7 2a 0a call 0xa2ac780
20: e8 5b f8 36 00 call 0x36f880
25: fb sti
26: 48 8b 5d c0 mov -0x40(%rbp),%rbx
* 2a: 48 8d bb f8 15 00 00 lea 0x15f8(%rbx),%rdi <-- trapping instruction
31: 48 89 f8 mov %rdi,%rax
34: 48 c1 e8 03 shr $0x3,%rax
38: 49 rex.WB
39: be 00 00 00 00 mov $0x0,%esi
3e: 00 fc add %bh,%ah