=============================
WARNING: suspicious RCU usage
6.9.0-rc7-next-20240509-syzkaller #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.1/21456:
#0: ffffc90000a18be0 ((&p->forward_delay_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x650 kernel/time/timer.c:1789
#1: ffff88802e878cb8 (&br->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#1: ffff88802e878cb8 (&br->lock){+.-.}-{2:2}, at: br_forward_delay_timer_expired+0x50/0x440 net/bridge/br_stp_timer.c:86
stack backtrace:
CPU: 1 PID: 21456 Comm: syz-executor.1 Not tainted 6.9.0-rc7-next-20240509-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
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: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+0x2d6/0x990 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 c9 d4 0b 00 48 83 c4 08 4c 89 f7 e8 ed 38 00 00 0f 1f 44 00 00 4c 89 f7 e8 70 b3 2e 0a e8 0b cc 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:ffffc900048df1c8 EFLAGS: 00000282
RAX: 696c4dcc7f0b9000 RBX: ffff88802eca9e00 RCX: ffffffff947a9603
RDX: dffffc0000000000 RSI: ffffffff8bcab500 RDI: ffffffff8c1fdb00
RBP: ffffc900048df210 R08: ffffffff8fad32ef R09: 1ffffffff1f5a65d
R10: dffffc0000000000 R11: fffffbfff1f5a65e R12: 1ffff110172a7ea7
R13: dffffc0000000000 R14: ffff8880b953e7c0 R15: ffff8880b953f538
context_switch kernel/sched/core.c:5411 [inline]
__schedule+0x17f0/0x4a50 kernel/sched/core.c:6745
__schedule_loop kernel/sched/core.c:6822 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6837
schedule_timeout+0xb0/0x310 kernel/time/timer.c:2557
unix_wait_for_peer+0x250/0x340 net/unix/af_unix.c:1457
unix_dgram_sendmsg+0x127a/0x1f80 net/unix/af_unix.c:2077
sock_sendmsg_nosec net/socket.c:730 [inline]
__sock_sendmsg+0x221/0x270 net/socket.c:745
____sys_sendmsg+0x525/0x7d0 net/socket.c:2584
___sys_sendmsg net/socket.c:2638 [inline]
__sys_sendmmsg+0x3b2/0x740 net/socket.c:2724
__do_sys_sendmmsg net/socket.c:2753 [inline]
__se_sys_sendmmsg net/socket.c:2750 [inline]
__x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2750
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: 0033:0x7f9f8a87dd69
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9f8b5130c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f9f8a9abf80 RCX: 00007f9f8a87dd69
RDX: 0000000000000318 RSI: 00000000200bd000 RDI: 0000000000000004
RBP: 00007f9f8a8ca49e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f9f8a9abf80 R15: 00007ffd7758b788
bridge0: port 1(bridge_slave_0) entered learning state
bridge0: port 2(bridge_slave_1) entered learning state
----------------
Code disassembly (best guess):
0: c9 leave
1: 50 push %rax
2: e8 c9 d4 0b 00 call 0xbd4d0
7: 48 83 c4 08 add $0x8,%rsp
b: 4c 89 f7 mov %r14,%rdi
e: e8 ed 38 00 00 call 0x3900
13: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
18: 4c 89 f7 mov %r14,%rdi
1b: e8 70 b3 2e 0a call 0xa2eb390
20: e8 0b cc 36 00 call 0x36cc30
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