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From: Peter Zijlstra <peterz@infradead.org>
To: Zicheng Qu <quzicheng@huawei.com>
Cc: mingo@redhat.com, juri.lelli@redhat.com,
	vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
	rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
	vschneid@redhat.com, linux-kernel@vger.kernel.org,
	tanghui20@huawei.com, zhangqiao22@huawei.com,
	judy.chenhui@huawei.com
Subject: Re: [PATCH] sched/fair: Fix overflow in vruntime_eligible() causing NULL return
Date: Thu, 10 Jul 2025 13:13:34 +0200	[thread overview]
Message-ID: <20250710111334.GD542000@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <d8588f5d-bccc-4791-9d44-bd3e383d21b9@huawei.com>

On Thu, Jul 10, 2025 at 10:01:15AM +0800, Zicheng Qu wrote:
> Hi,
> 
> Based on LTS 6.6. I also looked at the code logic around vruntime_eligible()
> in the mainline. It seems that if vruntime_eligible() consistently returned
> false, this could lead to null pointer dereferences.

That is a truly ancient kernel.  Please verify the issue is reproducible
on something recent.

Specifically, commit bbce3de72be5 ("sched/eevdf: Fix se->slice being set
to U64_MAX and resulting crash") cured something very similar to this.


  reply	other threads:[~2025-07-10 11:13 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-07-09  9:38 Zicheng Qu
2025-07-09 11:53 ` Peter Zijlstra
2025-07-10  2:01   ` Zicheng Qu
2025-07-10 11:13     ` Peter Zijlstra [this message]
2025-08-07  3:06 ` Fang Xiang
2025-08-08  9:21 quzicheng
2026-01-06 11:34 Fang Xiang

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