rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=370c/1/0x4000000000000000 softirq=61103/61104 fqs=5244
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:       12          0            0
rcu: 	cputime:      206      52293            7   ==> 52520(ms)
rcu: 	(t=10503 jiffies g=52049 q=3262 ncpus=2)
CPU: 0 UID: 0 PID: 15022 Comm: syz-executor Not tainted 6.15.0-rc1-syzkaller-00177-g8c941f14a694 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:taprio_next_tc_txq net/sched/sch_taprio.c:759 [inline]
RIP: 0010:taprio_dequeue_tc_priority+0x1c0/0x7a0 net/sched/sch_taprio.c:790
Code: df 42 0f b6 04 20 84 c0 0f 85 cb 01 00 00 41 8b 75 00 48 8b 7c 24 28 48 8b 54 24 40 8b 4c 24 1c e8 f5 05 00 00 48 89 44 24 10 <48> 89 e8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 b9 01 00 00 0f b7
RSP: 0018:ffffc90000007b08 EFLAGS: 00000282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88802756bc00
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff888064810800
RBP: ffff88805ed58044 R08: ffffffff8a26e5ef R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8a18a9f0 R12: dffffc0000000000
R13: ffff88806480a394 R14: 0000000000000001 R15: ffff88805ed58042
FS:  000055558be08500(0000) GS:ffff888124f94000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c265271 CR3: 00000000593a6000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 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+0x272/0x2180 net/sched/sch_generic.c:416
 qdisc_run+0xda/0x270 include/net/pkt_sched.h:127
 net_tx_action+0x898/0xa50 net/core/dev.c:5532
 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xfb/0x220 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__preempt_count_add kernel/rcu/tree.c:732 [inline]
RIP: 0010:rcu_is_watching+0x6/0xb0 kernel/rcu/tree.c:735
Code: 20 1a 98 03 eb cd 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 53 65 ff 05 10 fb bf 11 e8 3b 0a 88 0a 89 c3 83 f8 08 73 7a
RSP: 0018:ffffc9000464f3b0 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff88802756bc00
RDX: ffff88802756bc00 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000464f470 R08: ffffffff82192974 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 00007f71d851e000
R13: dffffc0000000000 R14: 1ffff920008c9e7c R15: ffffc9000464f500
 rcu_read_lock include/linux/rcupdate.h:842 [inline]
 ___pte_offset_map+0xbd/0x350 mm/pgtable-generic.c:287
 __pte_offset_map include/linux/mm.h:3117 [inline]
 __pte_offset_map_lock+0xd7/0x310 mm/pgtable-generic.c:398
 pte_offset_map_lock include/linux/mm.h:3132 [inline]
 __get_locked_pte mm/memory.c:2075 [inline]
 get_locked_pte include/linux/mm.h:2826 [inline]
 insert_page+0x177/0x310 mm/memory.c:2179
 kcov_mmap+0xc6/0x130 kernel/kcov.c:506
 call_mmap include/linux/fs.h:2243 [inline]
 mmap_file mm/internal.h:167 [inline]
 __mmap_new_file_vma mm/vma.c:2310 [inline]
 __mmap_new_vma mm/vma.c:2374 [inline]
 __mmap_region mm/vma.c:2476 [inline]
 mmap_region+0x241d/0x2ea0 mm/vma.c:2554
 do_mmap+0xd42/0x1420 mm/mmap.c:561
 vm_mmap_pgoff+0x2a2/0x530 mm/util.c:579
 ksys_mmap_pgoff+0x4ee/0x720 mm/mmap.c:607
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f71d978d1a3
Code: f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 41 89 ca 41 f7 c1 ff 0f 00 00 75 14 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 25 c3 0f 1f 40 00 48 c7 c0 a8 ff ff ff 64 c7
RSP: 002b:00007ffde38ebe98 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f71d99a5f40 RCX: 00007f71d978d1a3
RDX: 0000000000000003 RSI: 0000000000800000 RDI: 00007f71d7df9000
RBP: 00007f71d99a6738 R08: 00000000000000d7 R09: 0000000000000000
R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000008
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
sched: DL replenish lagged too much