============================= WARNING: suspicious RCU usage 6.9.0-syzkaller-12147-g13c7c941e729 #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.3/8353: #0: ffffc90000a18c00 ((&p->forward_delay_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x650 kernel/time/timer.c:1789 #1: ffff888063388cb8 (&br->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #1: ffff888063388cb8 (&br->lock){+.-.}-{2:2}, at: br_forward_delay_timer_expired+0x50/0x440 net/bridge/br_stp_timer.c:86 #2: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #2: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #2: ffffffff8e333e60 (rcu_read_lock){....}-{1:2}, at: br_mst_set_state+0x171/0x7a0 net/bridge/br_mst.c:105 stack backtrace: CPU: 1 PID: 8353 Comm: syz-executor.3 Not tainted 6.9.0-syzkaller-12147-g13c7c941e729 #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+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 f0 26 2a 0a e8 bb f6 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:ffffc90012837988 EFLAGS: 00000282 RAX: 7fb4cb76cd99dc00 RBX: ffff88802e76bc00 RCX: ffffffff9479d603 RDX: dffffc0000000000 RSI: ffffffff8bcab880 RDI: ffffffff8c1fe200 RBP: ffffc900128379d0 R08: ffffffff8fad34ef R09: 1ffffffff1f5a69d R10: dffffc0000000000 R11: fffffbfff1f5a69e 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: 0033:0x7fb7a6aa82f5 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:00007fff198c0780 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 0000000000000310 RCX: 00007fb7a6aa82f5 RDX: 00007fff198c07c0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fff198c084c R08: 0000000000000000 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032 R13: 000000000004aa90 R14: 000000000004aa02 R15: 0000000000000004 bridge0: port 1(team0) entered forwarding state bridge0: topology change detected, propagating ---------------- 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 f0 26 2a 0a call 0xa2a2710 20: e8 bb f6 36 00 call 0x36f6e0 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