rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4270/1:b..l
	(detected by 0, t=10502 jiffies, g=7985, q=286)
task:kworker/u4:8    state:R  running task     stack:25856 pid: 4270 ppid:     2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6780
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681
RIP: 0010:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 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 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc9000332faa0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 196b1f3e9dbd3000
RDX: 0000000000000000 RSI: ffffffff8a0b2260 RDI: ffffffff8a59a2c0
RBP: ffffc9000332fbc0 R08: dffffc0000000000 R09: fffffbfff1ff3419
R10: fffffbfff1ff3419 R11: 1ffffffff1ff3418 R12: ffffffff8c11bea0
R13: 1ffff92000665f60 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
 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 timer wakeup didn't happen for 10389 jiffies! g7985 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=2361
rcu: rcu_preempt kthread starved for 10390 jiffies! g7985 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27848 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4291 Comm: syz.0.10 Not tainted 5.15.182-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:__lock_acquire+0xd69/0x7c60 kernel/locking/lockdep.c:4982
Code: fc ff df 85 c0 0f 84 a5 4c 00 00 4c 89 ef 4c 89 fe ba 08 00 00 00 e8 16 a4 00 00 85 c0 0f 84 7b 4c 00 00 48 c7 c0 60 0f 0a 96 <48> c1 e8 03 49 b8 00 00 00 00 00 fc ff df 42 0f b6 04 00 84 c0 0f
RSP: 0018:ffffc900031efae0 EFLAGS: 00000002
RAX: ffffffff960a0f60 RBX: ffffffff8f9298f9 RCX: ffffffff815c98b4
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ff9a0d0
RBP: ffffc900031efd30 R08: dffffc0000000000 R09: fffffbfff1ff341b
R10: fffffbfff1ff341b R11: 1ffffffff1ff341a R12: ffff88807bc86450
R13: ffff88807bc85940 R14: 0000000000000000 R15: ffff88807bc86430
FS:  00005555663c0500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000007bdc3000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 do_write_seqcount_begin_nested include/linux/seqlock.h:519 [inline]
 do_write_seqcount_begin include/linux/seqlock.h:545 [inline]
 vtime_user_exit+0x95/0x400 kernel/sched/cputime.c:725
 __context_tracking_exit+0x4c/0x80 kernel/context_tracking.c:160
 user_exit_irqoff include/linux/context_tracking.h:47 [inline]
 __enter_from_user_mode kernel/entry/common.c:22 [inline]
 syscall_enter_from_user_mode+0x56/0x70 kernel/entry/common.c:110
 do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f2e0f236b39
Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 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 04 25
RSP: 002b:00007ffc83db5080 EFLAGS: 00000202 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007f2e0fff1720 RCX: 00007f2e0f236b39
RDX: 00007ffc83db5080 RSI: 00007ffc83db51b0 RDI: 0000000000000021
RBP: ffffffff83da7723 R08: 00007f2e0f4c2118 R09: 00007f2e0f4ae000
R10: 00007f2e0e509008 R11: 0000000000000202 R12: 000000000000000e
R13: 0000000000000000 R14: ffffffff83da74e1 R15: 00000000000003ff
 </TASK>