rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P32/1:b..l (detected by 0, t=10502 jiffies, g=14317, q=63 ncpus=2) task:kworker/u4:2 state:R running task stack:22872 pid:32 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:653 RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666 Code: 2b 00 74 08 4c 89 f7 e8 3f ac 77 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90000a97a20 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000152f50 RCX: 1ffff92000152ef0 RDX: dffffc0000000000 RSI: ffffffff8b0c14c0 RDI: ffffffff8b5d6dc0 RBP: ffffc90000a97b70 R08: dffffc0000000000 R09: fffffbfff223b845 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000152f4c R13: dffffc0000000000 R14: ffffc90000a97a80 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] batadv_nc_process_nc_paths+0xd6/0x390 net/batman-adv/network-coding.c:687 batadv_nc_worker+0x426/0x610 net/batman-adv/network-coding.c:728 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 starved for 10495 jiffies! g14317 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:26040 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: CPU: 0 PID: 4089 Comm: syz.1.68 Not tainted 6.1.111-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 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: 51 9b f5 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 3e 69 b9 f6 48 89 df e8 a6 a6 ba f6 e8 01 32 e0 f6 fb bf 01 00 00 00 46 37 ad f6 65 8b 05 17 2f 51 75 85 c0 74 02 5b c3 e8 c4 52 4f RSP: 0018:ffffc900048bfa30 EFLAGS: 00000286 RAX: 7e3df5f78a68bb00 RBX: ffff88802d0265c0 RCX: ffffffff97333103 RDX: dffffc0000000000 RSI: ffffffff8b0c0340 RDI: 0000000000000001 RBP: ffffc900048bfb10 R08: dffffc0000000000 R09: ffffed1005a04cb9 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff110034f34dc R13: ffff88801a799dc0 R14: 0000000100000000 R15: 1ffff110034f34db FS: 00007fd8136266c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020404030 CR3: 000000005adc6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: spin_unlock_irq include/linux/spinlock.h:401 [inline] __set_current_blocked+0x2a5/0x2f0 kernel/signal.c:3059 set_current_blocked kernel/signal.c:3043 [inline] signal_delivered kernel/signal.c:2906 [inline] signal_setup_done+0x397/0x5f0 kernel/signal.c:2918 handle_signal arch/x86/kernel/signal.c:846 [inline] arch_do_signal_or_restart+0xd5a/0x1a10 arch/x86/kernel/signal.c:873 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: 0033:0x7fd8127a6130 Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d 1a c8 06 00 e8 25 92 f8 ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48 RSP: 002b:00007fd813625b38 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007fd812935f88 RCX: 00007fd81277def9 RDX: 00007fd813625b40 RSI: 00007fd813625c70 RDI: 0000000000000021 RBP: 00007fd812935f80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd812935f8c R13: 0000000000000000 R14: 00007ffcb0343c00 R15: 00007ffcb0343ce8