rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P11/1:b..l
	(detected by 1, t=10503 jiffies, g=10489, q=68 ncpus=2)
task:kworker/u4:1    state:R  running task     stack:25568 pid:11    ppid:2      flags:0x00004000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
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+0x56/0x490 kernel/locking/lockdep.c:5630
Code: 14 48 89 7c 24 20 65 48 8b 04 25 28 00 00 00 48 89 84 24 c0 00 00 00 49 bf 00 00 00 00 00 fc ff df 48 c7 44 24 60 b3 8a b5 41 <48> c7 44 24 68 b9 2c 3c 8c 48 c7 44 24 70 80 f5 62 81 4c 8d 6c 24
RSP: 0018:ffffc90000107920 EFLAGS: 00000282
RAX: ad72d3ce097e0600 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8cb2aca0
RBP: ffffc90000107a28 R08: 0000000000000000 R09: 0000000000000000
R10: fffffbfff1c3ed96 R11: 1ffffffff1c3ed95 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000001 R15: dffffc0000000000
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:754 [inline]
 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:825 [inline]
 batadv_iv_ogm_schedule+0x413/0xe90 net/batman-adv/bat_iv_ogm.c:868
 batadv_iv_send_outstanding_bat_ogm_packet+0x72d/0x840 net/batman-adv/bat_iv_ogm.c:1712
 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! g10489 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:27840 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: 4508 Comm: syz.0.25 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:hlock_class kernel/locking/lockdep.c:223 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4724 [inline]
RIP: 0010:__lock_acquire+0x5b7/0x7c50 kernel/locking/lockdep.c:4999
Code: 00 31 db 48 81 c3 b8 00 00 00 48 89 d8 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 9e 61 00 00 44 0f b6 33 48 8b 44 24 50 0f b6 04 10 <84> c0 0f 85 ad 61 00 00 41 8b 07 89 c3 81 e3 ff 1f 00 00 c1 e8 03
RSP: 0018:ffffc90003707760 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffffff9047d5f8 RCX: ffffffff81630082
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff90ae2270
RBP: ffffc900037079b0 R08: dffffc0000000000 R09: fffffbfff215c44f
R10: fffffbfff215c44f R11: 1ffffffff215c44e R12: ffff88801dff3b80
R13: 0000000000000030 R14: 0000000000000003 R15: ffff88801dff4680
FS:  000055557e7b5500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e363fff CR3: 000000001d644000 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 include/linux/uaccess.h:75 [inline]
 check_xstate_in_sigframe arch/x86/kernel/fpu/signal.c:35 [inline]
 __fpu_restore_sig arch/x86/kernel/fpu/signal.c:348 [inline]
 fpu__restore_sig+0x203/0x1190 arch/x86/kernel/fpu/signal.c:493
 restore_sigcontext arch/x86/kernel/signal.c:140 [inline]
 __ia32_sys_rt_sigreturn+0x649/0x790 arch/x86/kernel/signal.c:675
 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: 0033:0x7f989b25ee2b
Code: 41 5e c3 0f 1f 40 00 48 8b 44 24 18 48 8b 1c 24 48 8b b0 80 00 00 00 8b 78 08 48 8d 53 30 e8 cc 56 ff ff 48 89 83 88 00 00 00 <e9> 45 fe ff ff 8b 7c 24 14 48 8d 74 24 40 ba 0f 00 00 00 e8 4d eb
RSP: 002b:00007ffd1998f0f0 EFLAGS: 00000206
RAX: 0000000000000000 RBX: 00007f989b5e5fa0 RCX: 00007f989b411f91
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f989b411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f989b5e5fa0 R14: 00007f989b5e5fa0 R15: 0000000000000004
 </TASK>