rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2658 jiffies s: 1169 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: 4400 Comm: syz.2.14 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:error_entry+0x17/0xf0 arch/x86/entry/entry_64.S:1036 Code: ff 85 db 0f 85 67 fe ff ff 0f 01 f8 e9 5f fe ff ff 90 90 56 48 8b 74 24 08 48 89 7c 24 08 52 51 50 41 50 41 51 41 52 41 53 53 <55> 41 54 41 55 41 56 41 57 56 31 f6 31 d2 31 c9 45 31 c0 45 31 c9 RSP: 0018:ffffc900000076e0 EFLAGS: 00000006 RAX: a60a562b4c1eb400 RBX: 1ffff92000000ef4 RCX: a60a562b4c1eb400 RDX: dffffc0000000000 RSI: ffffffff8a400e7b RDI: ffffffff8adf0de0 RBP: ffffc90000007860 R08: ffffffff90af5337 R09: 1ffffffff215ea66 R10: dffffc0000000000 R11: fffffbfff215ea67 R12: 0000000000000246 R13: dffffc0000000000 R14: ffff8880b8e3b900 R15: 0000000000000001 FS: 00007f26912d16c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f50317d4ff8 CR3: 0000000075878000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685 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 92 31 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc90000007760 EFLAGS: 00000206 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] ndisc_send_skb+0xd9d/0x14e0 net/ipv6/ndisc.c:521 addrconf_rs_timer+0x2d1/0x630 net/ipv6/addrconf.c:3979 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x53e/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x2a1/0x930 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x13b/0x230 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 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_acquire+0x225/0x4a0 kernel/locking/lockdep.c:5666 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04 RSP: 0018:ffffc900040a7ae0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: a60a562b4c1eb400 RDX: 0000000000000000 RSI: ffffffff8a8c23a0 RDI: ffffffff8adf0de0 RBP: ffffc900040a7bf8 R08: dffffc0000000000 R09: 1ffffffff215ea67 R10: dffffc0000000000 R11: fffffbfff215ea68 R12: 0000000000000000 R13: 1ffff92000814f68 R14: 0000000000000246 R15: dffffc0000000000 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] futex_wake+0x19a/0x4f0 kernel/futex/waitwake.c:164 do_futex+0x2e2/0x320 kernel/futex/syscalls.c:139 __do_sys_futex kernel/futex/syscalls.c:211 [inline] __se_sys_futex+0x381/0x410 kernel/futex/syscalls.c:192 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f269039c629 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:00007f26912d10e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f2690615fa8 RCX: 00007f269039c629 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f2690615fac RBP: 00007f2690615fa0 R08: 0029c710fd339720 R09: 0000000000000000 R10: 000000000000000a R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2690616038 R14: 00007fffb1e31070 R15: 00007fffb1e31158