rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P12/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=12053, q=695 ncpus=2)
task:kworker/u4:1    state:R  running task     stack:24744 pid:12    ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009
 irqentry_exit+0x67/0x70 kernel/entry/common.c:438
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lock_acquire+0x1f2/0x410 kernel/locking/lockdep.c:5758
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00
RSP: 0018:ffffc90000117a40 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 9130b3528116da00
RDX: 0000000000000000 RSI: ffffffff8aaacb40 RDI: ffffffff8afc66c0
RBP: ffffc90000117b48 R08: dffffc0000000000 R09: 1ffffffff21b46a0
R10: dffffc0000000000 R11: fffffbfff21b46a1 R12: 1ffff92000022f54
R13: ffffffff8cd2fbe0 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 rcu_read_lock include/linux/rcupdate.h:786 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: rcu_preempt kthread starved for 10512 jiffies! g12053 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27752 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6033 Comm: syz.0.17 Not tainted 6.6.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:rcu_is_watching+0x67/0xb0 kernel/rcu/tree.c:701
Code: 89 f7 e8 cc 3b 6d 00 48 c7 c3 48 6d 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 2f 8b 03 65 ff 0d 61 23 94 7e <74> 0c 83 e0 04 c1 e8 02 5b 41 5e 41 5f c3 e8 66 05 91 ff eb ed 48
RSP: 0018:ffffc9000377fa00 EFLAGS: 00000286
RAX: 000000000002689c RBX: ffff8880b8f36d48 RCX: d93a6329c3a43100
RDX: 0000000000000000 RSI: ffffffff8afc66a0 RDI: ffffffff8afc6660
RBP: ffffc9000377fb30 R08: ffffffff8e4a882f R09: 1ffffffff1c95105
R10: dffffc0000000000 R11: fffffbfff1c95106 R12: ffffffff81c8e6aa
R13: dffffc0000000000 R14: ffffffff8c7d1a38 R15: dffffc0000000000
FS:  00007f9b2b3b46c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000611ab000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 trace_lock_release include/trace/events/lock.h:69 [inline]
 lock_release+0xba/0x8b0 kernel/locking/lockdep.c:5765
 __copy_from_user include/linux/uaccess.h:97 [inline]
 check_xstate_in_sigframe arch/x86/kernel/fpu/signal.c:35 [inline]
 __fpu_restore_sig arch/x86/kernel/fpu/signal.c:348 [inline]
 fpu__restore_sig+0x19f/0x10e0 arch/x86/kernel/fpu/signal.c:493
 restore_sigcontext arch/x86/kernel/signal_64.c:95 [inline]
 __ia32_sys_rt_sigreturn+0x65d/0x7b0 arch/x86/kernel/signal_64.c:266
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9b2a58ebe9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9b2b3b40e8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f9b2a7b5fa8 RCX: 00007f9b2a58ebe9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f9b2a7b5fac
RBP: 00007f9b2a7b5fa0 R08: 0000000000745d1e R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9b2a7b6038 R14: 00007ffed4532b20 R15: 00007ffed4532c08
 </TASK>