============================= WARNING: suspicious RCU usage 6.9.0-rc6-syzkaller-00133-g19e35f24750d #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.1/32297: #0: ffffc90004f27b40 ((&p->forward_delay_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x650 kernel/time/timer.c:1790 #1: ffff88804e7d4cb8 (&br->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #1: ffff88804e7d4cb8 (&br->lock){+.-.}-{2:2}, at: br_forward_delay_timer_expired+0x50/0x440 net/bridge/br_stp_timer.c:86 stack backtrace: CPU: 1 PID: 32297 Comm: syz-executor.1 Not tainted 6.9.0-rc6-syzkaller-00133-g19e35f24750d #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+0x57/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0033:0x7f12cbe39a61 Code: f8 c1 e8 04 31 f8 69 c0 2d eb d4 27 89 c7 c1 ef 0f 31 f8 48 31 d0 25 ff 0f 00 00 09 c5 80 3d 56 bc c9 00 00 0f 85 6f ff ff ff <44> 0f b6 6c 24 0f 44 8d 55 04 89 e8 41 89 c1 41 81 e1 ff 1f 00 00 RSP: 002b:00007ffca938f3d0 EFLAGS: 00000246 RAX: 00000000000009f5 RBX: 00007f12cbfac018 RCX: 0000000000004ebf RDX: ffffffff814154be RSI: 0000000080000000 RDI: 0000000000016232 RBP: 00000000814159f5 R08: 0000001b31520000 R09: 0000000000001445 R10: 0000000081415449 R11: 0000000000000001 R12: 0000000000004ebf R13: 0000000000000001 R14: 00007f12cbfa0000 R15: ffffffff814154be bridge0: port 2(bridge_slave_1) entered learning state