=============================
WARNING: suspicious RCU usage
6.9.0-rc6-syzkaller-01554-g252aa6d53931 #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.2/5106:
#0: ffffc90000007c00 ((&p->forward_delay_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x650 kernel/time/timer.c:1790
#1: ffff888028bcccb8 (&br->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#1: ffff888028bcccb8 (&br->lock){+.-.}-{2:2}, at: br_forward_delay_timer_expired+0x50/0x440 net/bridge/br_stp_timer.c:86
stack backtrace:
CPU: 0 PID: 5106 Comm: syz-executor.2 Not tainted 6.9.0-rc6-syzkaller-01554-g252aa6d53931 #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:finish_task_switch+0x1ea/0x870 kernel/sched/core.c:5283
Code: c9 50 e8 39 d4 0b 00 48 83 c4 08 4c 89 f7 e8 9d 38 00 00 0f 1f 44 00 00 4c 89 f7 e8 40 d9 26 0a e8 3b 95 36 00 fb 48 8b 5d c0 <48> 8d bb f0 15 00 00 48 89 f8 48 c1 e8 03 49 be 00 00 00 00 00 fc
RSP: 0018:ffffc900039af968 EFLAGS: 00000286
RAX: 9095e46e84f47f00 RBX: ffff888029fabc00 RCX: ffffffff9473d603
RDX: dffffc0000000000 RSI: ffffffff8bcab900 RDI: ffffffff8c1f8600
RBP: ffffc900039af9b0 R08: ffffffff8fa9446f R09: 1ffffffff1f5288d
R10: dffffc0000000000 R11: fffffbfff1f5288e R12: 1ffff11017287e7f
R13: dffffc0000000000 R14: ffff8880b943e680 R15: ffff8880b943f3f8
context_switch kernel/sched/core.c:5412 [inline]
__schedule+0x17f0/0x4a50 kernel/sched/core.c:6746
__schedule_loop kernel/sched/core.c:6823 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6838
do_nanosleep+0x197/0x600 kernel/time/hrtimer.c:2051
hrtimer_nanosleep+0x227/0x470 kernel/time/hrtimer.c:2104
__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+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f96448a9175
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
RSP: 002b:00007ffea3312b70 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 000000000000044e RCX: 00007f96448a9175
RDX: 00007ffea3312bb0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffea3312c3c R08: 0000000000000000 R09: 00007f96456210b0
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032
R13: 00000000000345c3 R14: 00000000000345b0 R15: 000000000000000d
bridge0: port 1(bridge_slave_0) entered learning state
bridge0: port 2(bridge_slave_1) entered learning state
bridge0: port 3(erspan0) entered learning state
----------------
Code disassembly (best guess):
0: c9 leave
1: 50 push %rax
2: e8 39 d4 0b 00 call 0xbd440
7: 48 83 c4 08 add $0x8,%rsp
b: 4c 89 f7 mov %r14,%rdi
e: e8 9d 38 00 00 call 0x38b0
13: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
18: 4c 89 f7 mov %r14,%rdi
1b: e8 40 d9 26 0a call 0xa26d960
20: e8 3b 95 36 00 call 0x369560
25: fb sti
26: 48 8b 5d c0 mov -0x40(%rbp),%rbx
* 2a: 48 8d bb f0 15 00 00 lea 0x15f0(%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