rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4359/1:b..l (detected by 1, t=10502 jiffies, g=9477, q=188) task:kworker/u4:9 state:R running task stack:26112 pid: 4359 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: 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:ffffc90003d97aa0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 3c7a9f268e259100 RDX: 0000000000000000 RSI: ffffffff8a0b2e80 RDI: ffffffff8a59e800 RBP: ffffc90003d97bc0 R08: dffffc0000000000 R09: fffffbfff1ff5419 R10: fffffbfff1ff5419 R11: 1ffffffff1ff5418 R12: ffffffff8c11c720 R13: 1ffff920007b2f60 R14: 0000000000000246 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 rcu: rcu_preempt kthread timer wakeup didn't happen for 9611 jiffies! g9477 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=3925 rcu: rcu_preempt kthread starved for 9612 jiffies! g9477 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27008 pid: 15 ppid: 2 flags:0x00004000 Call Trace: 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 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: 4753 Comm: syz.2.153 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:55 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x54/0x290 mm/kasan/generic.c:189 Code: 0f 82 43 02 00 00 49 bf 01 00 00 00 00 fc ff df 49 89 fb 49 c1 eb 03 49 b8 00 00 00 00 00 fc ff df 4f 8d 0c 03 48 8d 5c 37 ff <48> c1 eb 03 4e 8d 14 3b 4d 89 d6 4d 29 ce 49 83 fe 10 7f 26 4d 85 RSP: 0018:ffffc90003d67960 EFLAGS: 00000802 RAX: 00000000ffffff01 RBX: ffffc90003d679c3 RCX: ffffffff815d4d6d RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90003d679c0 RBP: ffffc90003d67a30 R08: dffffc0000000000 R09: fffff520007acf38 R10: ffffed100f1a9834 R11: 1ffff920007acf38 R12: ffff888078d4c1a8 R13: ffff888078d4c1a0 R14: 1ffff1100f1a9835 R15: dffffc0000000001 FS: 00007f7d769986c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2c9d87708c CR3: 000000005ecf7000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:101 [inline] atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:512 [inline] queued_spin_lock include/asm-generic/qspinlock.h:82 [inline] do_raw_spin_lock+0x11d/0x280 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:117 [inline] _raw_spin_lock_irqsave+0xb0/0xf0 kernel/locking/spinlock.c:162 __lock_timer+0x28b/0x3b0 kernel/time/posix-timers.c:634 posixtimer_rearm+0x5c/0x340 kernel/time/posix-timers.c:324 dequeue_signal+0x174/0x440 kernel/signal.c:696 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: 0033:0x7f7d78773749 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:00007f7d769980e8 EFLAGS: 00000246 RAX: fffffffffffffffc RBX: 00007f7d789ca188 RCX: 00007f7d78773749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7d789ca188 RBP: 00007f7d789ca180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7d789ca218 R14: 00007ffe066ff0a0 R15: 00007ffe066ff188