rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (10476 ticks this GP) idle=e514/1/0x4000000000000000 softirq=80091/80169 fqs=4631 rcu: hardirqs softirqs csw/system rcu: number: 1464222 248 0 rcu: cputime: 19230 33247 43 ==> 52480(ms) rcu: (t=10500 jiffies g=101737 q=2825 ncpus=2) CPU: 1 PID: 22074 Comm: syz.2.4519 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:rcu_read_unlock_special+0x83/0x470 kernel/rcu/tree_plugin.h:698 Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 1e 0d 92 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc900001f00e0 EFLAGS: 00000206 RAX: a3bfc8b04a5cba00 RBX: 1ffff9200003e020 RCX: a3bfc8b04a5cba00 RDX: dffffc0000000000 RSI: ffffffff8acac900 RDI: ffffffff8b1c82e0 RBP: ffffc900001f01a8 R08: ffffffff911bf5c7 R09: 1ffffffff2237eb8 R10: dffffc0000000000 R11: fffffbfff2237eb9 R12: ffffffff8d137200 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000002 FS: 00007f17b04176c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000100000000 CR3: 000000007e166000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000200000000300 DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:818 [inline] is_bpf_text_address+0x27e/0x2a0 kernel/bpf/core.c:743 kernel_text_address+0xa0/0xd0 kernel/extable.c:125 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x270 mm/slub.c:3852 skb_kfree_head net/core/skbuff.c:947 [inline] skb_free_head net/core/skbuff.c:961 [inline] skb_release_data+0x60a/0x800 net/core/skbuff.c:991 skb_release_all net/core/skbuff.c:1057 [inline] __kfree_skb net/core/skbuff.c:1071 [inline] consume_skb+0xb2/0x110 net/core/skbuff.c:1287 nsim_start_xmit+0x9e/0xc0 drivers/net/netdevsim/netdev.c:42 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3632 [inline] dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3648 __dev_queue_xmit+0x1ac2/0x36b0 net/core/dev.c:4438 lapb_data_transmit+0x8a/0xa0 net/lapb/lapb_iface.c:447 lapb_transmit_buffer+0x163/0x200 net/lapb/lapb_out.c:149 lapb_t1timer_expiry+0x699/0xab0 net/lapb/lapb_timer.c:-1 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x542/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 1b 69 ce f6 65 8b 05 ec 9f 75 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc900101afac0 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a02 RCX: a3bfc8b04a5cba00 RDX: dffffc0000000000 RSI: ffffffff8acac900 RDI: 0000000000000001 RBP: ffffc900101afb50 R08: ffffffff8e8adeaf R09: 1ffffffff1d15bd5 R10: dffffc0000000000 R11: fffffbfff1d15bd6 R12: dffffc0000000000 R13: ffff8880420f8014 R14: ffff8880420f8a00 R15: 1ffff92002035f58 class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:522 [inline] try_to_wake_up+0x70a/0x1190 kernel/sched/core.c:4233 wake_up_process kernel/sched/core.c:4481 [inline] wake_up_q+0xb6/0x100 kernel/sched/core.c:1032 futex_wake+0x42a/0x4f0 kernel/futex/waitwake.c:184 do_futex+0x35d/0x3e0 kernel/futex/syscalls.c:139 __do_sys_futex kernel/futex/syscalls.c:211 [inline] __se_sys_futex+0x3a9/0x440 kernel/futex/syscalls.c:192 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f17af59c799 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:00007f17b04170e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f17af815fa8 RCX: 00007f17af59c799 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f17af815fac RBP: 00007f17af815fa0 R08: 0000000000745d1e R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f17af816038 R14: 00007fffecfd1c30 R15: 00007fffecfd1d18