rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P14766/1:b..l
(detected by 1, t=10503 jiffies, g=217141, q=288 ncpus=2)
task:kworker/u4:24 state:R running task stack:23088 pid:14766 ppid:2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x225/0x4a0 kernel/locking/lockdep.c:5666
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f0 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:ffffc9000c567a40 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: e5054202b5e84d00
RDX: 0000000000000000 RSI: ffffffff8a8c23a0 RDI: ffffffff8adf0d20
RBP: ffffc9000c567b58 R08: dffffc0000000000 R09: 1ffffffff215e848
R10: dffffc0000000000 R11: fffffbfff215e849 R12: 0000000000000001
R13: 1ffff920018acf54 R14: 0000000000000246 R15: dffffc0000000000
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
batadv_nc_process_nc_paths+0xdb/0x390 net/batman-adv/network-coding.c:687
batadv_nc_worker+0x425/0x600 net/batman-adv/network-coding.c:728
process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: rcu_preempt kthread starved for 3219 jiffies! g217141 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:26864 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6731
preempt_schedule+0xbc/0xd0 kernel/sched/core.c:6755
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0x10d/0x120 kernel/locking/spinlock.c:194
__mod_timer+0x91e/0xd00 kernel/time/timer.c:1134
schedule_timeout+0x17f/0x2d0 kernel/time/timer.c:2167
rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
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: 4244 Comm: syz.2.8040 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline]
RIP: 0010:static_key_false include/linux/jump_label.h:207 [inline]
RIP: 0010:trace_local_timer_exit arch/x86/include/asm/trace/irq_vectors.h:41 [inline]
RIP: 0010:__sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1125
Code: e8 42 80 9c 00 48 83 3b 00 0f 84 ab 00 00 00 65 ff 05 59 c1 cc 7e 43 80 3c 26 00 74 08 48 89 df e8 22 80 9c 00 48 89 df ff 13 <0f> 1f 44 00 00 65 8b 1d 51 3a cb 7e 48 c7 c0 70 cd 1f 8e 48 c1 e8
RSP: 0018:ffffc90000007fc8 EFLAGS: 00000096
RAX: 0000000000000000 RBX: ffff8880b8e27280 RCX: ffff88807d150000
RDX: 0000000000010000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff8e1fcb6f R09: 1ffffffff1c3f96d
R10: dffffc0000000000 R11: fffffbfff1c3f96e R12: dffffc0000000000
R13: 0000000000000000 R14: 1ffff110171c4e50 R15: 0000000000000000
FS: 00007f8b77c8d6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000005c8b4000 CR4: 00000000003506f0
Call Trace:
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 9e 12 2e f7 48 89 df e8 e6 da 2e f7 e8 a1 2d 52 f7 fb bf 01 00 00 00 86 3b 22 f7 65 8b 05 47 c0 cb 75 85 c0 74 02 5b c3 e8 94 d4 c9
RSP: 0018:ffffc90003117b98 EFLAGS: 00000282
RAX: 3bab99176a4a9100 RBX: ffff888067499280 RCX: 3bab99176a4a9100
RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: 0000000000000001
RBP: ffff888067499718 R08: ffff888067499283 R09: 1ffff1100ce93250
R10: dffffc0000000000 R11: ffffed100ce93251 R12: 1ffff1100ce932e3
R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x1163/0x1350 kernel/signal.c:2874
arch_do_signal_or_restart+0xc4/0x1350 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8b76d9aeb7
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:00007f8b77c8d0e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f8b77015fa8 RCX: 00007f8b76d9aeb9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f8b77015fa8
RBP: 00007f8b77015fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8b77016038 R14: 00007fff9edd2670 R15: 00007fff9edd2758