rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10501 ticks this GP) idle=4924/1/0x4000000000000000 softirq=89594/89594 fqs=0
rcu: 	(t=10502 jiffies g=78393 q=2607 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10502 jiffies! g78393 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=34812
rcu: rcu_preempt kthread starved for 10505 jiffies! g78393 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:26528 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: 18553 Comm: syz.9.3039 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:taprio_dequeue_tc_priority+0x25f/0x750 net/sched/sch_taprio.c:798
Code: 99 01 00 00 42 0f b6 44 25 00 84 c0 0f 85 33 02 00 00 41 8b 5d 00 4c 89 f0 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 39 02 00 00 <45> 8b 36 89 df 44 89 f6 e8 a4 86 50 f8 44 39 f3 73 15 48 8b 5c 24
RSP: 0018:ffffc90000a08cd8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 000000000000000b RCX: 0000000000000100
RDX: ffff888027ff8000 RSI: 000000000000000c RDI: 000000000000000b
RBP: 1ffff1100f18c06a R08: ffffffff896fcc56 R09: ffffffff8df41aa0
R10: 0000000000000001 R11: ffffffff89631050 R12: dffffc0000000000
R13: ffff888078c60354 R14: ffff888058fa04c8 R15: 0000000000000002
FS:  00007f8c981ee6c0(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f57dcdb7198 CR3: 000000003f128000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 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:lockdep_unregister_key+0x2ce/0x350 kernel/locking/lockdep.c:6616
Code: 41 5d 41 5e 41 5f 5d e9 50 f1 08 00 89 c7 e8 79 07 00 00 e9 6c fe ff ff e8 8f 8e bb 09 41 f7 c7 00 02 00 00 74 bb fb 40 84 ed <75> ba eb cb 90 0f 0b 90 e9 2e ff ff ff 90 0f 0b 90 e9 36 ff ff ff
RSP: 0018:ffffc90003347028 EFLAGS: 00000246
RAX: 0000000000000046 RBX: ffff88806bf7aa68 RCX: 0000000000000046
RDX: ffffffff9587df18 RSI: ffffffff8d7a6c59 RDI: ffffffff8bc08360
RBP: ffff888027ff8000 R08: ffffffff81ab3a98 R09: ffffffff8df41aa0
R10: dffffc0000000000 R11: ffffffff89631870 R12: 0000000000000000
R13: ffff88806bf7aa69 R14: 0000000000001000 R15: 0000000000000a07
 __qdisc_destroy+0x166/0x400 net/sched/sch_generic.c:1079
 taprio_destroy+0x263/0x550 net/sched/sch_taprio.c:2043
 __qdisc_destroy+0x153/0x400 net/sched/sch_generic.c:1077
 taprio_attach+0x25a/0x380 net/sched/sch_taprio.c:2161
 qdisc_graft+0x1175/0x1590 net/sched/sch_api.c:1162
 __tc_modify_qdisc net/sched/sch_api.c:1761 [inline]
 tc_modify_qdisc+0x16d3/0x2020 net/sched/sch_api.c:1817
 rtnetlink_rcv_msg+0x77c/0xb70 net/core/rtnetlink.c:6967
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x505/0x820 net/socket.c:2592
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2683 [inline]
 __se_sys_sendmsg net/socket.c:2681 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2681
 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: 0033:0x7f8c99f8f749
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:00007f8c981ee038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f8c9a1e5fa0 RCX: 00007f8c99f8f749
RDX: 0000000000000000 RSI: 00002000000007c0 RDI: 0000000000000005
RBP: 00007f8c9a013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8c9a1e6038 R14: 00007f8c9a1e5fa0 R15: 00007fff455b2bd8
 </TASK>
sched: DL replenish lagged too much