rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10501 ticks this GP) idle=1f8c/1/0x4000000000000000 softirq=50825/50825 fqs=0
rcu: 	(t=10502 jiffies g=33481 q=7409 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10502 jiffies! g33481 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=12633
rcu: rcu_preempt kthread starved for 10505 jiffies! g33481 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:27488 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x14bc/0x5000 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+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
CPU: 0 UID: 0 PID: 5830 Comm: syz-executor 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+0x83/0x980 net/sched/sch_taprio.c:712
Code: 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 ef e8 f2 ef b5 f8 4d 8b 6d 00 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 e7 e8 cf ef b5 f8 4d 63 ff 49 c1 e7 03 4d
RSP: 0018:ffffc90000007ad8 EFLAGS: 00000a06
RAX: 1ffff11009d90a50 RBX: ffff88804ec85000 RCX: dffffc0000000000
RDX: 0000000000000100 RSI: 000000000000000a RDI: ffff88804ec85000
RBP: 1ffff11009d90a6a R08: ffffffff897172b6 R09: ffffffff8df41a20
R10: 0000000000000001 R11: ffffffff8964b5e0 R12: ffff88804ec85280
R13: ffff8880786b4000 R14: ffff888058f7a400 R15: 000000000000000a
FS:  000055556f55d500(0000) GS:ffff888125e35000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc0f03156c0 CR3: 00000000759ee000 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+0x7ac/0x9f0 net/core/dev.c:5781
 handle_softirqs+0x27d/0x850 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x1f0 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:__sanitizer_cov_trace_const_cmp8+0x0/0x90 kernel/kcov.c:320
Code: 7c 11 10 48 89 74 11 18 48 89 44 11 20 e9 88 f4 9c 09 cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 b0 7e 92 65 8b 15 e8 f8
RSP: 0018:ffffc90003e6f380 EFLAGS: 00000246
RAX: 1ffffd40002fb4e1 RBX: dead000000000100 RCX: dffffc0000000000
RDX: ffff88802f100000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffff8233b88a R09: ffffffff8df41ae0
R10: dffffc0000000000 R11: fffff940002fb4e1 R12: ffffea00017da700
R13: ffff88805ffbb468 R14: 0000000000000001 R15: ffffea00017da700
 _compound_head include/linux/page-flags.h:286 [inline]
 PageAnon include/linux/page-flags.h:736 [inline]
 page_table_check_set+0xed/0x610 mm/page_table_check.c:110
 page_table_check_ptes_set include/linux/page_table_check.h:76 [inline]
 set_ptes include/linux/pgtable.h:292 [inline]
 __copy_present_ptes mm/memory.c:1102 [inline]
 copy_present_ptes mm/memory.c:1181 [inline]
 copy_pte_range mm/memory.c:1304 [inline]
 copy_pmd_range+0x4d02/0x7e00 mm/memory.c:1392
 copy_pud_range mm/memory.c:1429 [inline]
 copy_p4d_range mm/memory.c:1453 [inline]
 copy_page_range+0xb88/0x11d0 mm/memory.c:1535
 dup_mmap+0xf4a/0x1b80 mm/mmap.c:1827
 dup_mm kernel/fork.c:1529 [inline]
 copy_mm+0x13c/0x4b0 kernel/fork.c:1581
 copy_process+0x165d/0x3950 kernel/fork.c:2221
 kernel_clone+0x21e/0x820 kernel/fork.c:2651
 __do_sys_clone kernel/fork.c:2792 [inline]
 __se_sys_clone kernel/fork.c:2776 [inline]
 __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2776
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc0ef585e93
Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffc1292fd08 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc0ef585e93
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 000055556f55d7d0 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000000927c0 R14: 0000000000034e74 R15: 00007ffc1292fea0
 </TASK>
sched: DL replenish lagged too much