rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P524/1:b..l
(detected by 1, t=10502 jiffies, g=6637, q=38)
task:kworker/u4:3 state:R running task stack:25680 pid: 524 ppid: 2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 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_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681
RIP: 0010:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc9000381fa40 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: a3b0d425b051a600
RDX: 0000000000000000 RSI: ffffffff8a2b3a20 RDI: ffffffff8a79f980
RBP: ffffc9000381fb58 R08: dffffc0000000000 R09: 1ffffffff203a818
R10: dffffc0000000000 R11: fffffbfff203a819 R12: ffffffff8c31eaa0
R13: 1ffff92000703f54 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
rcu_read_lock include/linux/rcupdate.h:740 [inline]
batadv_nc_process_nc_paths+0xb2/0x350 net/batman-adv/network-coding.c:691
batadv_nc_worker+0x3e5/0x5c0 net/batman-adv/network-coding.c:732
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: rcu_preempt kthread starved for 10528 jiffies! g6637 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27800 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 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/0x11d0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
kthread+0x436/0x520 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: 4420 Comm: syz.1.48 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:__lock_acquire+0x1971/0x7d10 kernel/locking/lockdep.c:5015
Code: 52 00 00 83 3d a3 f8 2c 0c 00 48 8b 5c 24 40 4c 8b b4 24 b0 00 00 00 0f 84 fb 40 00 00 48 8b 84 24 c8 00 00 00 42 80 3c 00 00 <74> 12 4c 89 f7 e8 65 0e 61 00 49 b8 00 00 00 00 00 fc ff df 4d 89
RSP: 0018:ffffc900000078a0 EFLAGS: 00000046
RAX: 1ffff110058ba514 RBX: ffff88802c5d28a8 RCX: ffffffff815d1800
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901d40c0
RBP: ffffc90000007af0 R08: dffffc0000000000 R09: 1ffffffff203a818
R10: dffffc0000000000 R11: fffffbfff203a819 R12: 2e4489edb596d9f6
R13: ffff88802c5d1dc0 R14: ffff88802c5d28a0 R15: ffff88802c5d28f8
FS: 00007f568e3f66c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 000000002a2b2000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
debug_object_deactivate+0x62/0x390 lib/debugobjects.c:749
debug_hrtimer_deactivate kernel/time/hrtimer.c:415 [inline]
__run_hrtimer kernel/time/hrtimer.c:1653 [inline]
__hrtimer_run_queues+0x2b9/0xb70 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
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:__local_bh_disable_ip+0x68/0x1a0 kernel/softirq.c:326
Code: 62 d7 8b 48 c7 44 24 10 f0 39 49 81 49 89 e4 49 c1 ec 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4b 89 04 3c 43 c7 44 3c 08 f8 f3 f3 f3 <65> 8b 05 69 35 b9 7e a9 00 00 0f 00 0f 85 f5 00 00 00 43 c6 44 3c
RSP: 0018:ffffc900031efa80 EFLAGS: 00000a06
RAX: f2f2f2f8f1f1f1f1 RBX: 0000000000000200 RCX: 0000000000080000
RDX: ffffc90005199000 RSI: 0000000000000200 RDI: ffffffff812c61a5
RBP: ffffc900031efb30 R08: 0000000000000000 R09: 1ffff9200063df8f
R10: dffffc0000000000 R11: fffff5200063df90 R12: 1ffff9200063df50
R13: ffff88802c5d1dc0 R14: 00007f568e3f5c40 R15: dffffc0000000000
fpregs_lock arch/x86/include/asm/fpu/api.h:70 [inline]
restore_fpregs_from_user arch/x86/kernel/fpu/signal.c:257 [inline]
__fpu_restore_sig arch/x86/kernel/fpu/signal.c:334 [inline]
fpu__restore_sig+0x4fe/0x1060 arch/x86/kernel/fpu/signal.c:466
restore_sigcontext arch/x86/kernel/signal.c:139 [inline]
__ia32_sys_rt_sigreturn+0x5e4/0x760 arch/x86/kernel/signal.c:674
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f569019c817
Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89
RSP: 002b:00007f568e3f6028 EFLAGS: 00000246
RAX: 0000000000000049 RBX: 00007f5690415fa0 RCX: 00007f569019c819
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000004
RBP: 00007f5690232c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5690416038 R14: 00007f5690415fa0 R15: 00007ffd98415988
sched: RT throttling activated