rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=669/1/0x4000000000000000 softirq=22090/22094 fqs=5232 (t=10501 jiffies g=33733 q=2151) NMI backtrace for cpu 0 CPU: 0 PID: 9060 Comm: syz.4.1390 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 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+0x22d/0x380 kernel/rcu/tree_stall.h:349 print_cpu_stall+0x31f/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+0x6ec/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+0x4b0/0xb60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x397/0x8b0 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+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:preempt_count_sub+0x2a/0x160 kernel/sched/core.c:5536 Code: 55 53 48 bb 00 00 00 00 00 fc ff df 48 c7 c0 80 bf 11 97 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 bd 00 00 00 83 3d 16 66 bf 15 00 <75> 25 65 8b 05 55 16 b0 7e 89 c1 81 e1 ff ff ff 7f 39 cf 7f 25 81 RSP: 0018:ffffc90000006d30 EFLAGS: 00000246 RAX: 0000000000000004 RBX: dffffc0000000000 RCX: ffffffff9711bf03 RDX: ffffc900030fff00 RSI: ffffffff8a7a4b20 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffffc900030fff58 R09: 000000000000001b R10: dffffc0000000000 R11: fffff52000000dc5 R12: ffff88802b2abb80 R13: ffff888144bf0140 R14: 00007f9b38fe7275 R15: 1ffff92000000dc2 is_module_text_address+0xe0/0x140 kernel/module.c:4781 kernel_text_address kernel/extable.c:145 [inline] __kernel_text_address+0x84/0x100 kernel/extable.c:105 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x92/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] slab_alloc mm/slub.c:3233 [inline] kmem_cache_alloc+0x15d/0x280 mm/slub.c:3238 skb_clone+0x1bd/0x350 net/core/skbuff.c:1527 deliver_clone net/bridge/br_forward.c:125 [inline] maybe_deliver+0x98/0x150 net/bridge/br_forward.c:190 br_flood+0x2fc/0x450 net/bridge/br_forward.c:232 br_dev_xmit+0x10d3/0x1580 net/bridge/br_device.c:104 __netdev_start_xmit include/linux/netdevice.h:5049 [inline] netdev_start_xmit include/linux/netdevice.h:5063 [inline] xmit_one net/core/dev.c:3663 [inline] dev_hard_start_xmit+0x297/0x7d0 net/core/dev.c:3679 __dev_queue_xmit+0x195d/0x2e50 net/core/dev.c:4306 neigh_output include/net/neighbour.h:509 [inline] ip6_finish_output2+0x1174/0x1640 net/ipv6/ip6_output.c:132 dst_output include/net/dst.h:452 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ndisc_send_skb+0xb7c/0x1410 net/ipv6/ndisc.c:513 addrconf_rs_timer+0x367/0x640 net/ipv6/addrconf.c:3974 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648 expire_timers kernel/time/timer.c:1699 [inline] __run_timers+0x56c/0x810 kernel/time/timer.c:1970 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983 handle_softirqs+0x336/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:finish_lock_switch+0x12f/0x290 kernel/sched/core.c:4804 Code: 83 c7 18 be ff ff ff ff e8 be bc 6d 08 85 c0 74 46 4d 85 ff 75 62 0f 1f 44 00 00 48 89 df e8 58 2d 77 08 e8 a3 f2 2a 00 fb 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 2f 0e fe ff 43 80 3c 2c RSP: 0018:ffffc900030ffc78 EFLAGS: 00000282 RAX: 07ef842da85f2d00 RBX: ffff888027a43b80 RCX: 07ef842da85f2d00 RDX: dffffc0000000000 RSI: ffffffff8a2b2b60 RDI: ffffffff8a7a4b40 RBP: 1ffff110171c7613 R08: ffff8880b8e3b30b R09: 1ffff110171c7661 R10: dffffc0000000000 R11: ffffed10171c7662 R12: 1ffff110171c75c1 R13: dffffc0000000000 R14: ffff8880b8e3ae08 R15: 0000000000000000 finish_task_switch+0x12f/0x650 kernel/sched/core.c:4921 context_switch kernel/sched/core.c:5052 [inline] __schedule+0x11cb/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 exit_to_user_mode_loop+0x47/0x130 kernel/entry/common.c:172 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:217 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:323 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0033:0x7f9b38fe7275 Code: ff 48 8d 3d 30 22 1d 00 e8 38 f4 fe ff 0f 1f 84 00 00 00 00 00 41 56 48 8d 15 57 91 25 00 41 54 55 53 48 83 ec 78 48 63 47 28 <48> 89 7c 24 08 48 8d 74 24 30 bf 01 00 00 00 89 44 24 18 48 8d 04 RSP: 002b:00007f9b37379050 EFLAGS: 00000206 RAX: 000000000000009e RBX: 00007f9b393a8fa8 RCX: 00007f9b39121559 RDX: 00007f9b392403c0 RSI: 0000000000000080 RDI: 00007f9b393a8fa0 RBP: 00007f9b393a8fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9b393a9038 R14: 00007fffec02c930 R15: 00007fffec02ca18