rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6488/1:b..l
(detected by 1, t=10502 jiffies, g=41217, q=43)
task:kworker/u4:19 state:R running task stack:23448 pid: 6488 ppid: 2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6799
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:171 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0xc/0x60 kernel/kcov.c:205
Code: 89 fb e8 17 00 00 00 48 8b 3d c0 04 12 0c 48 89 de 5b e9 57 65 44 00 00 00 cc cc 00 00 cc 48 8b 04 24 65 48 8b 0d 14 60 89 7e <65> 8b 15 15 60 89 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75
RSP: 0018:ffffc9000352fbd8 EFLAGS: 00000202
RAX: ffffffff8994f7df RBX: dffffc0000000000 RCX: ffff888026509dc0
RDX: 0000000000000000 RSI: ffffffff8a7a4520 RDI: ffffffff8a7a44e0
RBP: 0000000000000001 R08: dffffc0000000000 R09: 1ffffffff203de18
R10: dffffc0000000000 R11: fffffbfff203de19 R12: 0000000000000177
R13: 0000000000000000 R14: ffff888061dfcc80 R15: ffff88801e534d90
rcu_read_unlock include/linux/rcupdate.h:769 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline]
batadv_nc_worker+0x1df/0x5c0 net/batman-adv/network-coding.c:723
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g41217 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=17678
rcu: rcu_preempt kthread starved for 10502 jiffies! g41217 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:I stack:27440 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
rcu_gp_fqs_loop+0x2be/0x11f0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9657 Comm: kworker/0:9 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_power_efficient neigh_periodic_work
RIP: 0010:__lock_acquire+0x27fd/0x7b50 kernel/locking/lockdep.c:5039
Code: 02 0f 0b 31 db 48 c7 84 24 00 01 00 00 0e 36 e0 45 48 8b 84 24 c0 00 00 00 4a c7 04 00 00 00 00 00 4a c7 44 00 08 00 00 00 00 <4a> c7 44 00 10 00 00 00 00 42 c7 44 00 18 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc9000300f000 EFLAGS: 00000083
RAX: 1ffff92000601e20 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901ef0c0
RBP: ffffc9000300f230 R08: dffffc0000000000 R09: 1ffffffff203de18
R10: dffffc0000000000 R11: fffffbfff203de19 R12: 1327c56e96c53cda
R13: ffff888023b7bb80 R14: ffff888023b7c668 R15: 1327c56e96c53cda
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c382e7f CR3: 00000000601cb000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
rcu_read_lock include/linux/rcupdate.h:740 [inline]
__perf_event_output kernel/events/core.c:7810 [inline]
perf_event_output_forward+0xbc/0x2e0 kernel/events/core.c:7832
__perf_event_overflow+0x35f/0x550 kernel/events/core.c:9525
perf_swevent_overflow kernel/events/core.c:9601 [inline]
perf_swevent_event+0x4b8/0x540 kernel/events/core.c:9639
perf_tp_event+0x324/0xbe0 kernel/events/core.c:10057
perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10031
perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14
trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 f2 0f 9d 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc9000300fa40 EFLAGS: 00000206
RAX: 759e21662a32ca00 RBX: 1ffff92000601f4c RCX: 759e21662a32ca00
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a4540
RBP: ffffc9000300fb18 R08: ffffffff901ef0ff R09: 1ffffffff203de1f
R10: dffffc0000000000 R11: fffffbfff203de20 R12: ffffffff8c323400
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock include/linux/rcupdate.h:772 [inline]
__neigh_notify+0x282/0x2e0 net/core/neighbour.c:3395
neigh_cleanup_and_release+0x9d/0x250 net/core/neighbour.c:101
neigh_periodic_work+0x406/0xc70 net/core/neighbour.c:947
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287