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=10502 jiffies, g=50661, q=37 ncpus=2) task:kworker/u4:1 state:R running task stack:22168 pid:11 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:rcu_is_watching+0x63/0xb0 kernel/rcu/tree.c:722 Code: 89 f7 e8 e0 a7 6e 00 48 c7 c3 a8 56 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 1e 8b 03 65 ff 0d 75 e7 8e 7e <74> 0c 83 e0 04 c1 e8 02 5b 41 5e 41 5f c3 e8 32 0b 8d ff eb ed 89 RSP: 0018:ffffc90000107bd8 EFLAGS: 00000286 RAX: 000000000029de94 RBX: ffff8880b8e356a8 RCX: ffff888017f53b80 RDX: ffff888017f53b80 RSI: ffffffff8b5e6960 RDI: ffffffff8b5e6920 RBP: ffff888075f2ceb0 R08: ffffffff8a83608d R09: fffffbfff224a04d R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88802b9c0c80 R13: 00000000000001d6 R14: ffffffff8cda7970 R15: dffffc0000000000 rcu_read_lock include/linux/rcupdate.h:792 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0x107/0x610 net/batman-adv/network-coding.c:719 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread timer wakeup didn't happen for 10522 jiffies! g50661 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=49031 rcu: rcu_preempt kthread starved for 10528 jiffies! g50661 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:26144 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 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: 12068 Comm: syz.5.1999 Not tainted 6.1.128-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:35 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline] RIP: 0010:lock_release+0x17a/0xa20 kernel/locking/lockdep.c:5678 Code: eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 0f 67 77 00 4c 89 6c 24 48 48 c7 84 24 b0 00 00 00 00 00 00 00 9c 8f 84 24 b0 00 00 00 <42> 80 3c 3b 00 74 08 4c 89 f7 e8 67 66 77 00 4c 8b ac 24 b0 00 00 RSP: 0018:ffffc90000007ae0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 1ffff92000000f72 RCX: ffffffff816ac867 RDX: 0000000000000000 RSI: ffffffff8b5e6960 RDI: ffffffff8b5e6920 RBP: ffffc90000007c10 R08: dffffc0000000000 R09: fffffbfff1d36536 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000000f68 R13: ffffffff8156ba87 R14: ffffc90000007b90 R15: dffffc0000000000 FS: 00007f4444fd06c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4444170220 CR3: 000000007da53000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_release include/linux/rcupdate.h:355 [inline] rcu_read_unlock include/linux/rcupdate.h:824 [inline] send_sigqueue+0x573/0x720 kernel/signal.c:2010 posix_timer_event kernel/time/posix-timers.c:359 [inline] posix_timer_fn+0x186/0x390 kernel/time/posix-timers.c:385 __run_hrtimer kernel/time/hrtimer.c:1689 [inline] __hrtimer_run_queues+0x5e5/0xe50 kernel/time/hrtimer.c:1753 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1815 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x158/0x5b0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: a1 95 f5 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 8e 87 ad f6 48 89 df e8 86 c5 ae f6 e8 11 1d d4 f6 fb bf 01 00 00 00 76 4f a1 f6 65 8b 05 17 2f 45 75 85 c0 74 02 5b c3 e8 c4 52 43 RSP: 0018:ffffc9000f72fb30 EFLAGS: 00000286 RAX: efc8acd1f38d7700 RBX: ffff88802f6b2500 RCX: ffffffff97357103 RDX: dffffc0000000000 RSI: ffffffff8b0c0340 RDI: 0000000000000001 RBP: ffffc9000f72fc70 R08: dffffc0000000000 R09: ffffed1005ed64a1 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff11005ed6533 R13: 000000001c000004 R14: 0000000000000021 R15: ffff88802f6b2998 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x154b/0x17d0 kernel/signal.c:2874 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f444418cde7 Code: ff ff 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 RSP: 002b:00007f4444fd0038 EFLAGS: 00000246 RAX: 0000000000000113 RBX: 00007f44443a5fa0 RCX: 00007f444418cde9 RDX: 0000000000000006 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007f444420e2a0 R08: 0000000008000f28 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f44443a5fa0 R15: 00007ffefe557c28