rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5769/1:b..l
	(detected by 1, t=10502 jiffies, g=60829, q=341)
task:kworker/u4:12   state:R  running task     stack:21880 pid: 5769 ppid:     2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 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_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:rcu_lock_acquire+0x1d/0x30 include/linux/rcupdate.h:313
Code: e8 98 86 2c f8 e9 5f ff ff ff 0f 1f 00 e8 cb 67 e7 f7 e8 c6 67 e7 f7 48 c7 c7 20 f3 31 8c 31 f6 31 d2 b9 02 00 00 00 45 31 c0 <45> 31 c9 68 45 ce 91 89 e8 a6 43 cb f7 48 83 c4 08 c3 90 e8 9b 67
RSP: 0018:ffffc90003397bd8 EFLAGS: 00000246
RAX: ffffffff8991ce4a RBX: dffffc0000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8c31f320
RBP: ffff88801f499440 R08: 0000000000000000 R09: 1ffffffff1b13f05
R10: dffffc0000000000 R11: fffffbfff1b13f06 R12: 0000000000000318
R13: ffff888076de18c0 R14: ffff888050444c80 R15: ffff88801f499450
 rcu_read_lock include/linux/rcupdate.h:740 [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+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
 </TASK>
rcu: rcu_preempt kthread starved for 10233 jiffies! g60829 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:27416 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 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
 </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: 14836 Comm: syz.0.2266 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:check_preemption_disabled+0x59/0x110 lib/smp_processor_id.c:19
Code: 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d c3 48 c7 04 24 00 00 00 00 9c 8f 04 24 <f7> 04 24 00 02 00 00 74 cc 65 4c 8b 3d 96 95 45 76 41 f6 47 2f 04
RSP: 0018:ffffc90003287b28 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000080000000
RDX: 0000000000000000 RSI: ffffffff8a2b3f00 RDI: ffffffff8a7a0700
RBP: ffffc90003287c80 R08: ffffffff8d89f82f R09: 1ffffffff1b13f05
R10: dffffc0000000000 R11: fffffbfff1b13f06 R12: ffff888016c6ce28
R13: 1ffff92000650f78 R14: 0000000000000246 R15: dffffc0000000000
FS:  00007feae9fef6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007feae9fcdff8 CR3: 0000000046b51000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lockdep_recursion_inc kernel/locking/lockdep.c:431 [inline]
 lock_acquire+0x166/0x400 kernel/locking/lockdep.c:5622
 __might_fault+0xb3/0x110 mm/memory.c:5357
 _copy_from_user+0x29/0x170 lib/usercopy.c:14
 copy_from_user include/linux/uaccess.h:192 [inline]
 restore_sigcontext arch/x86/kernel/signal.c:91 [inline]
 __ia32_sys_rt_sigreturn+0x21d/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: 0033:0x7feaebd371d9
Code: 11 06 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 0c 25
RSP: 002b:00007feae9feea80 EFLAGS: 00000202 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007feaec00efa0 RCX: 00007feaebd371d9
RDX: 00007feae9feea80 RSI: 00007feae9feebb0 RDI: 0000000000000021
RBP: 00007feaebe2bd6f R08: 0000000000001000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007feaec00f038 R14: 00007feaec00efa0 R15: 00007ffe4ab06218
 </TASK>