syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (2 ticks this GP) idle=d264/1/0x4000000000000002 softirq=24477/24477 fqs=74
	(detected by 1, t=10504 jiffies, g=26349, q=9163 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 10189 Comm: syz.2.2725 Not tainted 6.1.131-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x58/0x60 kernel/kcov.c:234
Code: f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc 15 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 <c3> 0f 1f 80 00 00 00 00 4c 8b 04 24 65 48 8b 15 14 c5 77 7e 65 8b
RSP: 0018:ffffc900000075b8 EFLAGS: 00000006
RAX: ffffffff81978de4 RBX: 0000000000000000 RCX: ffff88801db01dc0
RDX: 0000000000010100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90000007698 R08: ffffffff81978d66 R09: ffffed10171c7718
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffffffff8cdf5970 R14: 0000000000000046 R15: ffff8880b8e33fc0
FS:  00007f13b09a06c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000400000000140 CR3: 0000000058503000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 irq_work_run_list kernel/irq_work.c:237 [inline]
 irq_work_run+0x2b4/0x350 kernel/irq_work.c:253
 __sysvec_irq_work+0xbb/0x360 arch/x86/kernel/irq_work.c:22
 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
 sysvec_irq_work+0x4a/0xc0 arch/x86/kernel/irq_work.c:17
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:rcu_read_unlock_special+0x84/0x540 kernel/rcu/tree_plugin.h:682
Code: f1 f1 f1 00 f2 f2 f2 49 89 04 17 66 41 c7 44 17 09 f3 f3 41 c6 44 17 0b f3 65 44 8b 25 2d 0a 8e 7e 41 f7 c4 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 3a 00 00 00 00 66 42 c7 44 3a
RSP: 0018:ffffc90000007780 EFLAGS: 00000206
RAX: c3e522fe02b28400 RBX: 1ffff92000000ef8 RCX: ffffffff816b249a
RDX: dffffc0000000000 RSI: ffffffff8b0c1d40 RDI: ffffffff8b5f6f80
RBP: ffffc90000007858 R08: dffffc0000000000 R09: fffffbfff225726d
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff8d333500
R13: ffff88801db02218 R14: ffffc900000077c0 R15: 1ffff92000000ef4
 __rcu_read_unlock+0x92/0x100 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 ndisc_send_skb+0xdb6/0x15f0 net/ipv6/ndisc.c:521
 addrconf_rs_timer+0x357/0x610 net/ipv6/addrconf.c:3982
 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504
 expire_timers kernel/time/timer.c:1549 [inline]
 __run_timers+0x67c/0x890 kernel/time/timer.c:1820
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0x157/0x240 kernel/softirq.c:661
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:673
 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:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:212
Code: e8 25 00 00 00 0f 0b 0f 1f 00 53 48 89 fb e8 17 00 00 00 48 8b 3d e8 0c 16 0d 48 89 de 5b e9 67 8a 56 00 cc cc cc cc cc cc cc <48> 8b 04 24 65 48 8b 0d 74 c5 77 7e 65 8b 15 75 c5 77 7e 81 e2 00
RSP: 0018:ffffc9000ca17ae0 EFLAGS: 00000246
RAX: 1ffff9200192af8c RBX: ffffc9000c957c60 RCX: ffff88801db01dc0
RDX: 0000000000000000 RSI: ffffc90000a16948 RDI: ffffc9000c957c58
RBP: ffffc9000c957c58 R08: ffffffff817e23f0 R09: ffffed100b8d6776
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc9000c957c58
R13: ffffc9000c957c58 R14: ffffc90000a16948 R15: dffffc0000000000
 plist_check_prev_next lib/plist.c:35 [inline]
 plist_check_list+0x1ff/0x220 lib/plist.c:48
 plist_check_head lib/plist.c:59 [inline]
 plist_del+0x56/0x410 lib/plist.c:114
 __futex_unqueue+0xec/0x160 kernel/futex/core.c:518
 futex_wake_mark+0xf9/0x170 kernel/futex/waitwake.c:123
 futex_wake+0x3bb/0x590 kernel/futex/waitwake.c:177
 do_futex+0x375/0x490 kernel/futex/syscalls.c:111
 __do_sys_futex kernel/futex/syscalls.c:183 [inline]
 __se_sys_futex+0x3d7/0x460 kernel/futex/syscalls.c:164
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f13afb8d169
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:00007f13b09a00e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f13afda5fa8 RCX: 00007f13afb8d169
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f13afda5fac
RBP: 00007f13afda5fa0 R08: 0000000000000010 R09: 0000000000000000
R10: 000000000000043b R11: 0000000000000246 R12: 00007f13afda5fac
R13: 0000000000000000 R14: 00007ffffc30a3d0 R15: 00007ffffc30a4b8
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10134 jiffies! g26349 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=7944
rcu: rcu_preempt kthread starved for 10135 jiffies! g26349 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:26712 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5243 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6560
 schedule+0xbf/0x180 kernel/sched/core.c:6636
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 10184 Comm: syz.2.2725 Not tainted 6.1.131-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x1b4/0x200 arch/x86/kernel/kvm.c:1064
Code: e0 48 c1 e8 03 42 0f b6 04 28 84 c0 75 42 45 0f b6 34 24 e8 1e 0e 55 00 44 3a 74 24 1c 75 10 66 90 0f 00 2d 5e 1f cd 09 fb f4 <e9> c8 fe ff ff fb e9 c2 fe ff ff 44 89 e1 80 e1 07 38 c1 0f 8c 54
RSP: 0018:ffffc9000c957820 EFLAGS: 00000246
RAX: 2798c53bede05400 RBX: 1ffff9200192af08 RCX: ffffffff816b249a
RDX: dffffc0000000000 RSI: ffffffff8b0c1d40 RDI: ffffffff8b5f6f80
RBP: ffffc9000c9578f0 R08: dffffc0000000000 R09: fffffbfff2257266
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc90000a16908
R13: dffffc0000000000 R14: 0000000000000003 R15: ffffc9000c957860
FS:  00005555613da500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f894ff762d8 CR3: 0000000058503000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 pv_wait arch/x86/include/asm/paravirt.h:603 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x6fb/0xc50 kernel/locking/qspinlock.c:511
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
 queued_spin_lock_slowpath+0x42/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x269/0x370 kernel/locking/spinlock_debug.c:115
 spin_lock include/linux/spinlock.h:351 [inline]
 futex_unqueue+0x4a/0xf0 kernel/futex/core.c:597
 futex_wait+0x20b/0x5c0 kernel/futex/waitwake.c:660
 do_futex+0x3b5/0x490 kernel/futex/syscalls.c:106
 __do_sys_futex kernel/futex/syscalls.c:183 [inline]
 __se_sys_futex+0x3d7/0x460 kernel/futex/syscalls.c:164
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f13afb8d169
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:00007ffffc30a618 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 0000000000034b5a RCX: 00007f13afb8d169
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f13afda5fac
RBP: 0000000000000032 R08: 0000000000000010 R09: 00000004fc30a90f
R10: 00007ffffc30a710 R11: 0000000000000246 R12: 00007f13afda5fac
R13: 00007ffffc30a710 R14: 0000000000034b8c R15: 00007ffffc30a730
 </TASK>