rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12189/1:b..l rcu: (detected by 1, t=10502 jiffies, g=63553, q=1497 ncpus=2) task:syz.4.1710 state:R running task stack:25656 pid:12189 tgid:12188 ppid:5838 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090 irqentry_exit+0x6f/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:should_resched arch/x86/include/asm/preempt.h:104 [inline] RIP: 0010:__local_bh_enable_ip+0x135/0x1c0 kernel/softirq.c:414 Code: 8b e8 2f ba d0 09 65 66 8b 05 6f f7 ef 10 66 85 c0 75 5a bf 01 00 00 00 e8 c8 08 0b 00 e8 b3 86 41 00 fb 65 8b 05 4b f7 ef 10 <85> c0 75 05 e8 b2 9b ad ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00 RSP: 0018:ffffc900042ff940 EFLAGS: 00000286 RAX: 0000000080000000 RBX: 0000000000000200 RCX: e75d348810746c00 RDX: 0000000000000000 RSI: ffffffff8d74de43 RDI: ffffffff8bc1f3c0 RBP: ffffc900042ff9d0 R08: ffffffff8f7f3277 R09: 1ffffffff1efe64e R10: dffffc0000000000 R11: fffffbfff1efe64f R12: ffffffff898018c5 R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff9200085ff28 local_bh_enable include/linux/bottom_half.h:33 [inline] bpf_test_run+0x3fc/0x830 net/bpf/test_run.c:437 bpf_prog_test_run_skb+0xb30/0x1560 net/bpf/test_run.c:1093 bpf_prog_test_run+0x2a9/0x340 kernel/bpf/syscall.c:4427 __sys_bpf+0x4a4/0x860 kernel/bpf/syscall.c:5852 __do_sys_bpf kernel/bpf/syscall.c:5941 [inline] __se_sys_bpf kernel/bpf/syscall.c:5939 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5939 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb7fe38e969 RSP: 002b:00007fb7ff268038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fb7fe5b5fa0 RCX: 00007fb7fe38e969 RDX: 0000000000000050 RSI: 0000200000000640 RDI: 000000000000000a RBP: 00007fb7fe410ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb7fe5b5fa0 R15: 00007fff611913f8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10530 jiffies! g63553 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=23565 rcu: rcu_preempt kthread starved for 10531 jiffies! g63553 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:26328 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2046 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5988 Comm: kworker/u8:28 Not tainted 6.15.0-rc7-syzkaller-00105-g57a92d14659d #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: bat_events batadv_nc_worker RIP: 0010:taprio_dequeue_from_txq+0x12/0x900 net/sched/sch_taprio.c:703 Code: f8 48 8b 5c 24 10 eb ae 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 48 83 ec 30 89 4c 24 0c <49> 89 d6 41 89 f7 48 89 fb 49 bc 00 00 00 00 00 fc ff df e8 e6 ff RSP: 0018:ffffc90000007ae0 EFLAGS: 00000282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000026f RDX: ffff888011caac00 RSI: 0000000000000008 RDI: ffff88806c5ac000 RBP: 1ffff1100d8b5872 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff896ab1c0 R12: dffffc0000000000 R13: ffff88806c5ac394 R14: 0000000000000010 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8881260c2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb7ff267f98 CR3: 0000000068878000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: taprio_dequeue_tc_priority+0x1ac/0x750 net/sched/sch_taprio.c:787 taprio_dequeue+0x186/0x550 net/sched/sch_taprio.c:-1 dequeue_skb net/sched/sch_generic.c:293 [inline] qdisc_restart net/sched/sch_generic.c:398 [inline] __qdisc_run+0x239/0x15f0 net/sched/sch_generic.c:416 qdisc_run+0xc2/0x230 include/net/pkt_sched.h:127 net_tx_action+0x7c9/0x980 net/core/dev.c:5534 handle_softirqs+0x286/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:should_resched arch/x86/include/asm/preempt.h:104 [inline] RIP: 0010:__local_bh_enable_ip+0x135/0x1c0 kernel/softirq.c:414 Code: 8b e8 2f ba d0 09 65 66 8b 05 6f f7 ef 10 66 85 c0 75 5a bf 01 00 00 00 e8 c8 08 0b 00 e8 b3 86 41 00 fb 65 8b 05 4b f7 ef 10 <85> c0 75 05 e8 b2 9b ad ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00 RSP: 0018:ffffc90004def980 EFLAGS: 00000282 RAX: 0000000080000000 RBX: 0000000000000201 RCX: 4488d090c47f2e00 RDX: 0000000000000006 RSI: ffffffff8d74de43 RDI: ffffffff8bc1f3c0 RBP: ffffc90004defa18 R08: ffffffff8f7f3277 R09: 1ffffffff1efe64e R10: dffffc0000000000 R11: fffffbfff1efe64f R12: ffffffff8b24ec28 R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff920009bdf30 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_nc_purge_paths+0x318/0x3b0 net/batman-adv/network-coding.c:471 batadv_nc_worker+0x369/0x610 net/batman-adv/network-coding.c:722 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xadb/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245