rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4338/1:b..l
	(detected by 1, t=10502 jiffies, g=14817, q=13)
task:kworker/u4:10   state:R  running task     stack:25856 pid: 4338 ppid:     2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 preempt_schedule_irq+0xb1/0x150 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:rcu_lock_acquire+0x25/0x30 include/linux/rcupdate.h:312
Code: ff ff 0f 1f 00 e8 4b 15 f9 f7 e8 46 15 f9 f7 48 c7 c7 60 c6 11 8c 31 f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 68 d5 b5 7e 89 <e8> 36 42 dd f7 48 83 c4 08 c3 90 e8 1b 15 f9 f7 e8 16 15 f9 f7 48
RSP: 0018:ffffc90003d1fbd0 EFLAGS: 00000246
RAX: ffffffff897eb5da RBX: dffffc0000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8c11c660
RBP: ffff8880626cbc80 R08: 0000000000000000 R09: 0000000000000000
R10: fffffbfff1ad323e R11: 1ffffffff1ad323d R12: 0000000000000302
R13: ffff88807bc31810 R14: ffff8880621dcc80 R15: ffff8880626cbc90
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
 batadv_nc_worker+0xc9/0x5c0 net/batman-adv/network-coding.c:723
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: rcu_preempt kthread starved for 10527 jiffies! g14817 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:26624 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </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: 5604 Comm: syz.4.377 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:205
Code: 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 00 c9 f1 0b 48 89 de 5b e9 47 9e 43 00 00 00 cc cc 00 00 cc 48 8b 04 24 <65> 48 8b 0d 94 a4 8a 7e 65 8b 15 95 a4 8a 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc9000343fb18 EFLAGS: 00000246
RAX: ffffffff812bc881 RBX: 00007f6eb55acd00 RCX: a33018b357da2200
RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480
RBP: ffffc9000343fcb0 R08: dffffc0000000000 R09: ffffed1027fd3c81
R10: ffffed1027fd3c81 R11: 1ffff11027fd3c80 R12: dffffc0000000000
R13: 00007f6eb55acd00 R14: ffff88802a86f0c8 R15: ffff88802a86d940
FS:  00007f6eb55ad6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000005cd08000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 copy_fpstate_to_sigframe+0x871/0xb90 arch/x86/kernel/fpu/signal.c:214
 get_sigframe arch/x86/kernel/signal.c:295 [inline]
 __setup_rt_frame arch/x86/kernel/signal.c:471 [inline]
 setup_rt_frame arch/x86/kernel/signal.c:780 [inline]
 handle_signal arch/x86/kernel/signal.c:824 [inline]
 arch_do_signal_or_restart+0x67a/0x1300 arch/x86/kernel/signal.c:869
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f6eb7345ec7
Code: ff ff 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
RSP: 002b:00007f6eb55ad0e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f6eb759cfa8 RCX: 00007f6eb7345ec9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6eb759cfa8
RBP: 00007f6eb759cfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6eb759d038 R14: 00007fff1b0866b0 R15: 00007fff1b086798
 </TASK>