rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4785/1:b..l
	(detected by 1, t=10503 jiffies, g=22997, q=53 ncpus=2)
task:kworker/u4:18   state:R  running task     stack:24040 pid:4785  ppid:2      flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666
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 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc90003bb7ac0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 91c8d2e861d5d800
RDX: 0000000000000000 RSI: ffffffff8a8c1480 RDI: ffffffff8adefae0
RBP: ffffc90003bb7bc8 R08: dffffc0000000000 R09: fffffbfff215c249
R10: fffffbfff215c249 R11: 1ffffffff215c248 R12: 0000000000000001
R13: 1ffff92000776f64 R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
 batadv_nc_worker+0xeb/0x600 net/batman-adv/network-coding.c:719
 process_one_work+0x898/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: rcu_preempt kthread starved for 10528 jiffies! g22997 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:27040 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 schedule+0xb9/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </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: 5578 Comm: syz.7.190 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__lock_acquire+0xdaa/0x7c50 kernel/locking/lockdep.c:5019
Code: e8 03 49 b8 00 00 00 00 00 fc ff df 42 0f b6 04 00 84 c0 0f 85 a6 5b 00 00 83 3d a0 7c 5b 15 00 48 8b 84 24 a8 00 00 00 75 34 <48> 63 d8 48 89 d8 48 c1 e8 06 48 8d 3c c5 40 12 ae 90 be 08 00 00
RSP: 0018:ffffc900038177e0 EFLAGS: 00000046
RAX: 000000000000019b RBX: ffff88802fedc640 RCX: ffffffff96be8103
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90ae1270
RBP: ffffc90003817a30 R08: dffffc0000000000 R09: fffffbfff215c24f
R10: fffffbfff215c24f R11: 1ffffffff215c24e R12: ffff88802fedbb80
R13: ffff88802fedc604 R14: ffff88802fedc660 R15: ffff88802fedc680
FS:  00007ffb91dfa6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffb91df9f40 CR3: 0000000079898000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 __might_fault+0xc2/0x120 mm/memory.c:5852
 _copy_from_user+0x27/0x170 lib/usercopy.c:14
 copy_from_user include/linux/uaccess.h:161 [inline]
 restore_altstack+0x9a/0x4a0 kernel/signal.c:4257
 __ia32_sys_rt_sigreturn+0x660/0x790 arch/x86/kernel/signal.c:678
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ffb90f8ebe9
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:00007ffb91dfa0e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007ffb911c6098 RCX: 00007ffb90f8ebe9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ffb911c6098
RBP: 00007ffb911c6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffb911c6128 R14: 00007fff6e538750 R15: 00007fff6e538838
 </TASK>