rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10501 ticks this GP) idle=3b04/1/0x4000000000000000 softirq=63728/63728 fqs=0
rcu: 	(t=10502 jiffies g=50765 q=1938 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10502 jiffies! g50765 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=24143
rcu: rcu_preempt kthread starved for 10505 jiffies! g50765 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27480 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
CPU: 1 UID: 0 PID: 14471 Comm: syz.1.2565 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:taprio_dequeue_from_txq+0xb2/0x980 net/sched/sch_taprio.c:712
Code: 08 4c 89 e7 e8 8f 9f b6 f8 4d 63 ff 49 c1 e7 03 4d 03 3c 24 4c 89 f8 48 c1 e8 03 49 bc 00 00 00 00 00 fc ff df 42 80 3c 20 00 <74> 08 4c 89 ff e8 64 9f b6 f8 4c 89 74 24 08 49 8b 2f 4d 8d 7d 36
RSP: 0018:ffffc90000a08c70 EFLAGS: 00000246
RAX: 1ffff11006001f8b RBX: ffff888141efd000 RCX: dffffc0000000000
RDX: 0000000000000100 RSI: 000000000000000b RDI: ffff888141efd000
RBP: 1ffff110283dfa6a R08: ffffffff896fcc56 R09: ffffffff8df41aa0
R10: 0000000000000001 R11: ffffffff89631050 R12: dffffc0000000000
R13: ffff8880760e4000 R14: ffff88807baae400 R15: ffff88803000fc58
FS:  000055557b73c500(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc318de7dac CR3: 000000007bc2e000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 taprio_dequeue_tc_priority+0x1ac/0x750 net/sched/sch_taprio.c:793
 taprio_dequeue+0x186/0x550 net/sched/sch_taprio.c:-1
 dequeue_skb net/sched/sch_generic.c:297 [inline]
 qdisc_restart net/sched/sch_generic.c:402 [inline]
 __qdisc_run+0x23f/0x1510 net/sched/sch_generic.c:420
 qdisc_run+0xc7/0x300 include/net/pkt_sched.h:120
 net_tx_action+0x717/0x900 net/core/dev.c:5782
 handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x60/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:futex_q_lock+0x0/0x60 kernel/futex/core.c:868
Code: 03 38 c1 0f 8c 38 ff ff ff 48 c7 c7 a0 53 82 8f e8 85 f8 72 00 e9 27 ff ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <0f> 1f 40 d6 41 56 53 48 89 f3 49 89 fe e8 5e d8 0c 00 48 89 df be
RSP: 0018:ffffc900053ef980 EFLAGS: 00000286
RAX: ffff88802eb80640 RBX: ffffc900053efae8 RCX: ffff888025073d00
RDX: 0000000000000000 RSI: ffff88802eb80640 RDI: ffffc900053efaa0
RBP: 0000000000000003 R08: ffffffff81b3f6a0 R09: ffffffff8df41aa0
R10: 0000000000000000 R11: 00000000ffffffff R12: dffffc0000000000
R13: ffffc900053efaa0 R14: ffff88802eb80640 R15: 00007fc318de5fac
 futex_wait_setup+0xd7/0x590 kernel/futex/waitwake.c:625
 __futex_wait+0x148/0x3d0 kernel/futex/waitwake.c:682
 futex_wait+0x104/0x360 kernel/futex/waitwake.c:715
 do_futex+0x333/0x420 kernel/futex/syscalls.c:130
 __do_sys_futex kernel/futex/syscalls.c:207 [inline]
 __se_sys_futex+0x36f/0x400 kernel/futex/syscalls.c:188
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc318b8f749
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:00007ffc5335f538 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 0000000000056b03 RCX: 00007fc318b8f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc318de5fac
RBP: 0000000000000032 R08: 3fffffffffffffff R09: 000000015335f82f
R10: 00007ffc5335f630 R11: 0000000000000246 R12: 00007fc318de5fac
R13: 00007ffc5335f630 R14: 0000000000056b35 R15: 00007ffc5335f650
 </TASK>
sched: DL replenish lagged too much