rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P38/1:b..l rcu: (detected by 0, t=10502 jiffies, g=9081, q=371 ncpus=2) task:kworker/u4:2 state:R running task stack:21520 pid:38 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x14e2/0x4580 kernel/sched/core.c:6700 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7010 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:lock_acquire+0x1f2/0x410 kernel/locking/lockdep.c:5758 Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f5 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 66 43 c7 44 3c 09 00 00 43 c6 44 3c 0b 00 RSP: 0018:ffffc90000aefa40 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 777456de11bdb900 RDX: 0000000000000000 RSI: ffffffff8aaacac0 RDI: ffffffff8afc7880 RBP: ffffc90000aefb48 R08: dffffc0000000000 R09: 1ffffffff21b4ca4 R10: dffffc0000000000 R11: fffffbfff21b4ca5 R12: 1ffff9200015df54 R13: ffffffff8cd2fa60 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:334 [inline] rcu_read_lock include/linux/rcupdate.h:786 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: rcu_preempt kthread starved for 10523 jiffies! g9081 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:27496 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x14e2/0x4580 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5892 Comm: vhost-5890 Not tainted 6.6.97-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__get_user_nocheck_2+0x4/0x20 arch/x86/lib/getuser.S:114 Code: 90 90 90 90 90 90 f3 0f 1e fa 0f 01 cb 0f ae e8 0f b6 10 31 c0 0f 01 ca c3 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <0f> 01 cb 0f ae e8 0f b7 10 31 c0 0f 01 ca c3 90 90 90 90 90 90 90 RSP: 0018:ffffc90004a5fb60 EFLAGS: 00000206 RAX: 0000200000000482 RBX: ffff888041f64ca8 RCX: ffff88802db4da00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff90da660f R09: 1ffffffff21b4cc1 R10: dffffc0000000000 R11: fffffbfff21b4cc2 R12: dffffc0000000000 R13: ffff888041f64c08 R14: ffff888041f64bf8 R15: ffffc90004a5fb68 FS: 0000555584d673c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffde859f940 CR3: 000000002f532000 CR4: 00000000003506e0 Call Trace: vhost_get_avail_idx drivers/vhost/vhost.c:1364 [inline] vhost_enable_notify+0x39a/0x810 drivers/vhost/vhost.c:2913 vhost_vsock_handle_tx_kick+0x2cd/0xde0 drivers/vhost/vsock.c:502 vhost_run_work_list+0x13d/0x1b0 drivers/vhost/vhost.c:419 vhost_task_fn+0x25a/0x3c0 kernel/vhost_task.c:49 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293