============================= WARNING: suspicious RCU usage 6.9.0-rc7-syzkaller-01844-gcddd2dc6390b #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 5 locks held by kworker/u8:2/32: #0: ffff88802aaa9948 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3242 [inline] #0: ffff88802aaa9948 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x17c0 kernel/workqueue.c:3348 #1: ffffc90000a87d00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3243 [inline] #1: ffffc90000a87d00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x17c0 kernel/workqueue.c:3348 #2: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline] #2: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline] #2: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] #2: ffffffff8e334ea0 (rcu_read_lock){....}-{1:2}, at: batadv_nc_worker+0xcb/0x610 net/batman-adv/network-coding.c:719 #3: ffffc90000a08be0 ((&p->forward_delay_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc0/0x650 kernel/time/timer.c:1790 #4: ffff88806c1accb8 (&br->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline] #4: ffff88806c1accb8 (&br->lock){+.-.}-{2:2}, at: br_forward_delay_timer_expired+0x50/0x440 net/bridge/br_stp_timer.c:86 stack backtrace: CPU: 1 PID: 32 Comm: kworker/u8:2 Not tainted 6.9.0-rc7-syzkaller-01844-gcddd2dc6390b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Workqueue: bat_events batadv_nc_worker 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 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:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5758 Code: 2b 00 74 08 4c 89 f7 e8 9a 7c 88 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90000a879e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000150f48 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8bcaca80 RDI: ffffffff8c1f8980 RBP: ffffc90000a87b40 R08: ffffffff92f46507 R09: 1ffffffff25e8ca0 R10: dffffc0000000000 R11: fffffbfff25e8ca1 R12: 1ffff92000150f44 R13: dffffc0000000000 R14: ffffc90000a87a40 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:329 [inline] rcu_read_lock include/linux/rcupdate.h:781 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xec/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3267 [inline] process_scheduled_works+0xa10/0x17c0 kernel/workqueue.c:3348 worker_thread+0x86d/0xd70 kernel/workqueue.c:3429 kthread+0x2f0/0x390 kernel/kthread.c:388 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 bridge0: port 3(hsr0) entered learning state ---------------- Code disassembly (best guess): 0: 2b 00 sub (%rax),%eax 2: 74 08 je 0xc 4: 4c 89 f7 mov %r14,%rdi 7: e8 9a 7c 88 00 call 0x887ca6 c: f6 44 24 61 02 testb $0x2,0x61(%rsp) 11: 0f 85 85 01 00 00 jne 0x19c 17: 41 f7 c7 00 02 00 00 test $0x200,%r15d 1e: 74 01 je 0x21 20: fb sti 21: 48 c7 44 24 40 0e 36 movq $0x45e0360e,0x40(%rsp) 28: e0 45 * 2a: 4b c7 44 25 00 00 00 movq $0x0,0x0(%r13,%r12,1) <-- trapping instruction 31: 00 00 33: 43 c7 44 25 09 00 00 movl $0x0,0x9(%r13,%r12,1) 3a: 00 00 3c: 43 rex.XB 3d: c7 .byte 0xc7 3e: 44 rex.R 3f: 25 .byte 0x25