rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4295/1:b..l
	(detected by 1, t=10502 jiffies, g=13841, q=44)
task:kworker/u4:6    state:R  running task     stack:22112 pid: 4295 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:lockdep_enabled kernel/locking/lockdep.c:91 [inline]
RIP: 0010:lock_acquire+0x124/0x3f0 kernel/locking/lockdep.c:5599
Code: 65 8b 05 4f 7e a6 7e 85 c0 0f 85 2d 01 00 00 65 4c 8b 35 bf 74 a6 7e 49 81 c6 ec 0a 00 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 38 <84> c0 0f 85 f2 01 00 00 41 83 3e 00 0f 85 00 01 00 00 48 c7 84 24
RSP: 0018:ffffc9000409faa0 EFLAGS: 00000a03
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 5a846126d9d02d00
RDX: 0000000000000000 RSI: ffffffff8a59e560 RDI: ffffffff8a59e520
RBP: ffffc9000409fbc0 R08: dffffc0000000000 R09: fffffbfff1ad33a6
R10: fffffbfff1ad33a6 R11: 1ffffffff1ad33a5 R12: ffffffff8c11c760
R13: 1ffff92000813f60 R14: ffff8880209cc66c R15: dffffc0000000000
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
 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+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 10526 jiffies! g13841 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:28064 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: 5566 Comm: syz.5.296 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:stack_trace_consume_entry+0x23/0x270 kernel/stacktrace.c:86
Code: 00 00 00 00 0f 1f 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 18 48 ba 00 00 00 00 00 fc ff df 4c 8d 47 10 4c 89 c5 48 c1 ed 03 <0f> b6 44 15 00 84 c0 0f 85 04 01 00 00 44 8b 4f 10 4c 8d 77 08 4d
RSP: 0018:ffffc90003abf658 EFLAGS: 00000806
RAX: ffffffff81295211 RBX: ffffc90003abf760 RCX: 0000000080000001
RDX: dffffc0000000000 RSI: ffffffff81295211 RDI: ffffc90003abf760
RBP: 1ffff92000757eee R08: ffffc90003abf770 R09: ffffc90003abf6f8
R10: fffff52000757ee1 R11: 1ffff92000757edf R12: ffff88805daa8000
R13: ffff888031634150 R14: ffffffff81667ac0 R15: ffffc90003abf6a8
FS:  00007f21df6226c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000029fcb000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 arch_stack_walk+0x100/0x140 arch/x86/kernel/stacktrace.c:27
 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kmem_cache_free+0x8f/0x210 mm/slub.c:3520
 __sigqueue_free kernel/signal.c:458 [inline]
 collect_signal kernel/signal.c:597 [inline]
 __dequeue_signal+0x4c4/0x5d0 kernel/signal.c:619
 dequeue_signal+0xa2/0x440 kernel/signal.c:639
 get_signal+0x6fe/0x12c0 kernel/signal.c:2781
 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
 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: 0033:0x7f21e13bb749
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:00007f21df6220e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007f21e1611fa8 RCX: 00007f21e13bb749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f21e1611fa8
RBP: 00007f21e1611fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f21e1612038 R14: 00007ffc976ae010 R15: 00007ffc976ae0f8
 </TASK>