rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=ecb/1/0x4000000000000000 softirq=17741/17742 fqs=5129 (t=10500 jiffies g=22353 q=2586) NMI backtrace for cpu 0 CPU: 0 PID: 6941 Comm: syz.4.579 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_dump_cpu_stacks+0x22f/0x380 kernel/rcu/tree_stall.h:349 print_cpu_stall+0x31d/0x5f0 kernel/rcu/tree_stall.h:633 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0x6ea/0x1120 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:2021 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:cake_heap_get_backlog net/sched/sch_cake.c:1472 [inline] RIP: 0010:cake_heapify+0x256/0x6a0 net/sched/sch_cake.c:1495 Code: f0 c1 e8 03 25 ff 03 00 00 41 83 e6 07 49 69 ce d0 98 01 00 49 03 0f 4c 8d b4 81 00 40 01 00 4c 89 f0 48 c1 e8 03 0f b6 04 10 <84> c0 0f 85 5d 03 00 00 45 8b 36 44 89 f7 44 89 e6 e8 b4 be 64 f9 RSP: 0018:ffffc900015ae780 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: 0000000000001ab0 RCX: ffff888041f00000 RDX: dffffc0000000000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: 0000000000000d57 R08: ffffffff901d418f R09: 1ffffffff203a831 R10: dffffc0000000000 R11: fffffbfff203a832 R12: 0000000000000000 R13: 0000000000000d57 R14: ffff888041f14d58 R15: ffff888072c602d0 cake_drop net/sched/sch_cake.c:1575 [inline] cake_enqueue+0x33d9/0x7fc0 net/sched/sch_cake.c:1949 dev_qdisc_enqueue+0x48/0x210 net/core/dev.c:3865 __dev_xmit_skb net/core/dev.c:3949 [inline] __dev_queue_xmit+0xc25/0x2f80 net/core/dev.c:4266 tipc_l2_send_msg+0x30a/0x3c0 net/tipc/bearer.c:518 tipc_bearer_xmit_skb+0x292/0x3c0 net/tipc/bearer.c:577 tipc_enable_bearer net/tipc/bearer.c:368 [inline] __tipc_nl_bearer_enable+0xfba/0x12c0 net/tipc/bearer.c:1049 __tipc_nl_compat_doit net/tipc/netlink_compat.c:375 [inline] tipc_nl_compat_doit+0x3d9/0x610 net/tipc/netlink_compat.c:397 tipc_nl_compat_handle net/tipc/netlink_compat.c:-1 [inline] tipc_nl_compat_recv+0x536/0xaf0 net/tipc/netlink_compat.c:1325 genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline] genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0xcea/0xf90 net/netlink/genetlink.c:792 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2499 __sys_sendmsg net/socket.c:2528 [inline] __do_sys_sendmsg net/socket.c:2537 [inline] __se_sys_sendmsg+0x1af/0x290 net/socket.c:2535 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fe1e3235819 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe1e148f028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fe1e34aefa0 RCX: 00007fe1e3235819 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000004 RBP: 00007fe1e32cbc91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe1e34af038 R14: 00007fe1e34aefa0 R15: 00007ffc92b77818