Received-SPF: pass (google.com: domain of linux-kernel+bounces-76347-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45e3:2400::1 as permitted sender) client-ip=2604:1380:45e3:2400::1;
From: Hillf Danton <hdanton@sina.com>
To: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Edward Adam Davis <eadavis@qq.com>,
	syzbot+116b65a23bc791ae49a6@syzkaller.appspotmail.com,
	linux-kernel@vger.kernel.org,
	linux-media@vger.kernel.org,
	mchehab@kernel.org,
	syzkaller-bugs@googlegroups.com
Subject: Re: [PATCH] media/cec/core: fix task hung in cec_claim_log_addrs
Date: Thu, 22 Feb 2024 18:43:20 +0800
Message-Id: <20240222104320.236-1-hdanton@sina.com>
In-Reply-To: <4fa62e4f-9768-4434-8f7b-24aa3b2a3490@xs4all.nl>
References: <0000000000006d96200611de3986@google.com> <tencent_941B48254CBA00BB4933069E391B6E4B5408@qq.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

On Wed, 21 Feb 2024 15:38:47 +0100 Hans Verkuil <hverkuil-cisco@xs4all.nl>
> On 21/02/2024 15:20, Edward Adam Davis wrote:
> > After unlocking adap->lock in cec_claim_log_addrs(), cec_claim_log_addrs() may
> > re-enter, causing this issue to occur.
> 
> But if it is called again, then it should hit this at the start of the function:
> 
>         if (WARN_ON(adap->is_configuring || adap->is_configured))
>                 return;
> 
> I'm still not sure what causes the KASAN hung task since I cannot seem to reproduce
> it, and because it is hard for me to find enough time to dig into this.

Likely because of the window for initializing completion more than once [1].

[1] https://lore.kernel.org/lkml/00000000000054a54e0611f1bc01@google.com/