rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6692/1:b..l
	(detected by 1, t=10502 jiffies, g=97821, q=63)
task:kworker/u4:17   state:R  running task     stack:22280 pid: 6692 ppid:     2 flags:0x00004000
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
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: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:ffffc9000398f900 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 8a75ef20a5ea8f00
RDX: 0000000000000000 RSI: ffffffff8a0b28c0 RDI: ffffffff8a59a240
RBP: ffffc9000398fa20 R08: dffffc0000000000 R09: fffffbfff1ff7619
R10: fffffbfff1ff7619 R11: 1ffffffff1ff7618 R12: ffffffff8c11c460
R13: 1ffff92000731f2c R14: 0000000000000246 R15: dffffc0000000000
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [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+0x432/0xe90 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+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 10528 jiffies! g97821 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:27168 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: 20138 Comm: syz.1.3143 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
RIP: 0010:hlock_class kernel/locking/lockdep.c:197 [inline]
RIP: 0010:mark_lock+0x7e/0x320 kernel/locking/lockdep.c:4569
Code: d3 e4 4d 8d 7e 20 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 22 02 00 00 41 8b 07 41 89 c7 41 81 e7 ff 1f 00 00 c1 e8 03 <25> f8 03 00 00 48 8d b8 c0 b0 fb 8f be 08 00 00 00 e8 3c 83 5f 00
RSP: 0018:ffffc90002f2f7c0 EFLAGS: 00000006
RAX: 000000000000a033 RBX: ffff888073e35940 RCX: 0000000000000009
RDX: 0000000000000008 RSI: ffff888073e36430 RDI: ffff888073e35940
RBP: 0000000000000009 R08: dffffc0000000000 R09: fffffbfff1ff761f
R10: fffffbfff1ff761f R11: 1ffffffff1ff761e R12: 0000000000000200
R13: dffffc0000000000 R14: ffff888073e36430 R15: 000000000000019b
FS:  0000555582e27500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31b14ff8 CR3: 000000007cf55000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 mark_usage kernel/locking/lockdep.c:4512 [inline]
 __lock_acquire+0xd5a/0x7c60 kernel/locking/lockdep.c:4966
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __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_altstack+0x9a/0x360 kernel/signal.c:4252
 __ia32_sys_rt_sigreturn+0x660/0x790 arch/x86/kernel/signal.c:677
 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: 0033:0x7fcc8e8f49e7
Code: 1f 40 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 89 fb 44 8d 56 04 4c 8d 0d 22 46 36 00 89 f0 4c 8d 05 19 26 36 00 <89> c2 81 e2 ff 1f 00 00 49 8b 0c d1 48 39 f1 74 28 48 85 c9 74 29
RSP: 002b:00007ffe32b74798 EFLAGS: 00000246
RAX: 00000000814ab2a8 RBX: 00007fcc8f79c720 RCX: 000000000004c308
RDX: ffffffff814abcb4 RSI: ffffffff814ab2a8 RDI: 0000000000000009
RBP: ffffffff814ab2a8 R08: 00007fcc8ec57000 R09: 00007fcc8ec59000
R10: 00000000814ab2ac R11: 0000000000000009 R12: 0000000000000009
R13: 000000000000029a R14: ffffffff814abcb4 R15: 000000000004c308
 </TASK>