rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4354/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=12309, q=507 ncpus=2)
task:kworker/u4:9    state:R  running task     stack:22312 pid:4354  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010
 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+0x208/0x420 kernel/locking/lockdep.c:5758
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 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 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc9000e6cf9c0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ef311384baae8300
RDX: 0000000000000000 RSI: ffffffff8acadb60 RDI: ffffffff8b1c8fa0
RBP: ffffc9000e6cfad8 R08: dffffc0000000000 R09: 1ffffffff2238ca0
R10: dffffc0000000000 R11: fffffbfff2238ca1 R12: 1ffff92001cd9f44
R13: ffffffff8d1320e0 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 rcu_read_lock include/linux/rcupdate.h:786 [inline]
 batadv_nc_process_nc_paths+0xdb/0x390 net/batman-adv/network-coding.c:687
 batadv_nc_worker+0x429/0x610 net/batman-adv/network-coding.c:728
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
 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 10533 jiffies! g12309 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:27656 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x1553/0x45a0 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
 rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x9d/0x3b0 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5940 Comm: syz.2.19 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:copy_fpstate_to_sigframe+0x76e/0xc60 arch/x86/kernel/fpu/signal.c:192
Code: 45 84 f6 75 16 e8 32 55 55 00 e9 ed fb ff ff e8 28 55 55 00 0f 0b e9 25 ff ff ff e8 1c 55 55 00 e8 97 d0 ce ff e9 d2 fb ff ff <4c> 39 7c 24 48 0f 84 2c 01 00 00 48 8b 44 24 50 42 80 3c 28 00 4c
RSP: 0018:ffffc900015f78e0 EFLAGS: 00000246
RAX: ffffffff8131ca3d RBX: ffff88807a468000 RCX: 0000000000000000
RDX: ffff88807a468000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900015f7ad0 R08: ffffffff8e8b19af R09: 1ffffffff1d16335
R10: dffffc0000000000 R11: fffffbfff1d16336 R12: ffff88807a469950
R13: dffffc0000000000 R14: 0000000000000000 R15: 00007ffc97dbc340
FS:  000055555e065500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d063fff CR3: 000000007dec6000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 get_sigframe+0x5e2/0x7d0 arch/x86/kernel/signal.c:142
 x64_setup_rt_frame+0x15e/0xc40 arch/x86/kernel/signal_64.c:175
 setup_rt_frame arch/x86/kernel/signal.c:223 [inline]
 handle_signal arch/x86/kernel/signal.c:267 [inline]
 arch_do_signal_or_restart+0x42c/0x800 arch/x86/kernel/signal.c:312
 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:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6326066092
Code: 89 de bf ff ff ff ff 44 0f b6 05 39 f6 ed 00 e8 94 f4 ff ff 80 3d 62 f6 ed 00 00 74 c9 48 89 df 5b e9 32 36 ff ff 66 90 41 57 <41> 56 41 55 41 54 49 89 fc 55 53 48 83 ec 18 8b 47 08 85 c0 0f 85
RSP: 002b:00007ffc97dbc710 EFLAGS: 00000217
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f632619cdd9
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f6326415fa0
RBP: 0000000000001e5b R08: 0000000000745d1e R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6326415fac R14: 00007f6326415fa8 R15: 00007f6326415fa0
 </TASK>