rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2652 jiffies s: 14133 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9204 Comm: syz.9.1136 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:cake_heapify+0x618/0x6a0 net/sched/sch_cake.c:-1
Code: a9 7f f9 e9 24 fe ff ff 44 89 e9 80 e1 07 fe c1 38 c1 0f 8c 3e fe ff ff 4c 89 ef e8 d2 a9 7f f9 e9 31 fe ff ff e8 a8 88 2f f9 <eb> 05 e8 a1 88 2f f9 48 83 c4 28 5b 41 5c 41 5d 41 5e 41 5f 5d c3
RSP: 0018:ffffc90000007140 EFLAGS: 00000246
RAX: ffffffff885147e8 RBX: 00000000000013f8 RCX: ffff888029c39dc0
RDX: 0000000000000100 RSI: 00000000000009fb RDI: 00000000000009fb
RBP: 00000000000009fb R08: dffffc0000000000 R09: fffffbfff215c484
R10: fffffbfff215c484 R11: 1ffffffff215c483 R12: 0000000000000000
R13: 00000000000009fb R14: 00000000000009fb R15: 00000000000009fb
FS:  00007f67a7cda6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c310a73 CR3: 000000005759e000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 cake_drop net/sched/sch_cake.c:1575 [inline]
 cake_enqueue+0x3195/0x7bc0 net/sched/sch_cake.c:1948
 cbs_child_enqueue net/sched/sch_cbs.c:95 [inline]
 cbs_enqueue_soft+0x1a8/0x270 net/sched/sch_cbs.c:128
 dev_qdisc_enqueue+0x4c/0x2b0 net/core/dev.c:3875
 __dev_xmit_skb net/core/dev.c:3964 [inline]
 __dev_queue_xmit+0xf8e/0x3760 net/core/dev.c:4312
 dev_queue_xmit include/linux/netdevice.h:3051 [inline]
 tipc_l2_send_msg+0x30f/0x3d0 net/tipc/bearer.c:518
 tipc_bearer_xmit_skb+0x2a9/0x3f0 net/tipc/bearer.c:577
 tipc_disc_timeout+0x568/0x6b0 net/tipc/discover.c:338
 call_timer_fn+0x1a0/0x670 kernel/time/timer.c:1504
 expire_timers kernel/time/timer.c:1549 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1820
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:rcu_is_watching+0x63/0xa0 kernel/rcu/tree.c:722
Code: 89 f7 e8 50 e3 65 00 48 c7 c3 c8 57 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 2f 8b 03 65 ff 0d a5 60 97 7e <74> 0c 83 e0 04 c1 e8 02 5b 41 5e 41 5f c3 e8 02 72 95 ff eb ed 48
RSP: 0018:ffffc90005ddf850 EFLAGS: 00000282
RAX: 0000000000484cb4 RBX: ffff8880b8e357c8 RCX: 7fc7cab0c2f4de00
RDX: ffffc9000dfcb000 RSI: ffffffff8adefc80 RDI: ffffffff8adefc40
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff215c449
R10: fffffbfff215c449 R11: 1ffffffff215c448 R12: dffffc0000000000
R13: 0000000000000120 R14: ffffffff8c5e4980 R15: dffffc0000000000
 rcu_read_lock_held_common kernel/rcu/update.c:108 [inline]
 rcu_read_lock_held+0x11/0x40 kernel/rcu/update.c:309
 lookup_page_ext mm/page_ext.c:277 [inline]
 page_ext_get+0x18f/0x2a0 mm/page_ext.c:158
 page_table_check_set+0x51/0x6d0 mm/page_table_check.c:112
 page_table_check_pte_set include/linux/page_table_check.h:83 [inline]
 set_pte_at arch/x86/include/asm/pgtable.h:1009 [inline]
 do_set_pte+0x452/0x460 mm/memory.c:4426
 finish_fault+0x7c1/0x8d0 mm/memory.c:4499
 do_read_fault mm/memory.c:4635 [inline]
 do_fault mm/memory.c:4760 [inline]
 handle_pte_fault mm/memory.c:5031 [inline]
 __handle_mm_fault mm/memory.c:5173 [inline]
 handle_mm_fault+0x28f2/0x3e70 mm/memory.c:5294
 faultin_page mm/gup.c:1026 [inline]
 __get_user_pages+0x3ff/0xeb0 mm/gup.c:1250
 populate_vma_page_range+0x214/0x2b0 mm/gup.c:1607
 __mm_populate+0x248/0x370 mm/gup.c:1721
 mm_populate include/linux/mm.h:2837 [inline]
 vm_mmap_pgoff+0x203/0x2b0 mm/util.c:525
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f67a6d8eba9
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:00007f67a7cda038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f67a6fd5fa0 RCX: 00007f67a6d8eba9
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f67a6e11e19 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f67a6fd6038 R14: 00007f67a6fd5fa0 R15: 00007ffeb2dde4f8
 </TASK>