rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4451/1:b..l (detected by 0, t=10503 jiffies, g=152845, q=65 ncpus=2) task:kworker/u4:17 state:R running task stack:20448 pid:4451 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_acquire+0x20f/0x490 kernel/locking/lockdep.c:5666 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 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b RSP: 0018:ffffc90003197ac0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 59de580b14c12000 RDX: 0000000000000000 RSI: ffffffff8a6c1160 RDI: ffffffff8abf1360 RBP: ffffc90003197bc8 R08: dffffc0000000000 R09: fffffbfff2117049 R10: fffffbfff2117049 R11: 1ffffffff2117048 R12: 0000000000000001 R13: 1ffff92000632f64 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xeb/0x600 net/batman-adv/network-coding.c:719 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread starved for 9910 jiffies! g152845 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:27848 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 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: 24195 Comm: syz.1.5305 Not tainted 6.1.141-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:raw_spin_rq_unlock_irq+0x13/0x90 kernel/sched/sched.h:1368 Code: 7c d2 e8 e0 8c 78 00 eb cb 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 66 90 41 57 41 56 53 eb 11 e8 64 d7 bf 08 e8 ef 6f 2d 00 fb 5b <41> 5e 41 5f c3 49 be 00 00 00 00 00 fc ff df 49 89 ff 48 8d 9f 58 RSP: 0018:ffffc9000c6bf928 EFLAGS: 00000282 RAX: 46117622546ee200 RBX: ffff8880b8e3b7f8 RCX: 46117622546ee200 RDX: dffffc0000000000 RSI: ffffffff8a6bffe0 RDI: ffffffff8abf1360 RBP: ffffc9000c6bfac8 R08: dffffc0000000000 R09: ffffed10171c7551 R10: ffffed10171c7551 R11: 1ffff110171c7550 R12: ffff88802a9ebb80 R13: dffffc0000000000 R14: dffffc0000000000 R15: ffff8880b8e3b7c8 FS: 00007f7e687ff6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7e68bb6088 CR3: 0000000076bc4000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __schedule+0x1379/0x40d0 kernel/sched/core.c:6567 schedule+0xb9/0x180 kernel/sched/core.c:6637 futex_wait_queue+0x134/0x1b0 kernel/futex/waitwake.c:355 futex_wait+0x19b/0x530 kernel/futex/waitwake.c:656 do_futex+0x310/0x320 kernel/futex/syscalls.c:106 __do_sys_futex kernel/futex/syscalls.c:183 [inline] __se_sys_futex+0x14a/0x440 kernel/futex/syscalls.c:164 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f7e6898e929 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:00007f7e687ff0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f7e68bb6088 RCX: 00007f7e6898e929 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f7e68bb6088 RBP: 00007f7e68bb6080 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7e68bb608c R13: 0000000000000000 R14: 00007ffc173bd3b0 R15: 00007ffc173bd498