Received-SPF: pass (google.com: domain of linux-kernel+bounces-159999-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Date: Fri, 26 Apr 2024 14:43:46 +0200
Message-ID: <877cgks399.wl-tiwai@suse.de>
From: Takashi Iwai <tiwai@suse.de>
To: Rajashekar kuruva <quic_kuruva@quicinc.com>
Cc: <srinivas.kandagatla@linaro.org>,
	<mathias.nyman@intel.com>,
	<perex@perex.cz>,
	<conor+dt@kernel.org>,
	<corbet@lwn.net>,
	<lgirdwood@gmail.com>,
	<andersson@kernel.org>,
	<krzysztof.kozlowski+dt@linaro.org>,
	<gregkh@linuxfoundation.org>,
	<Thinh.Nguyen@synopsys.com>,
	<broonie@kernel.org>,
	<bgoswami@quicinc.com>,
	<tiwai@suse.com>,
	<robh@kernel.org>,
	<konrad.dybcio@linaro.org>,
	<linux-kernel@vger.kernel.org>,
	<devicetree@vger.kernel.org>,
	<linux-sound@vger.kernel.org>,
	<linux-usb@vger.kernel.org>,
	<linux-arm-msm@vger.kernel.org>,
	<linux-doc@vger.kernel.org>,
	<alsa-devel@alsa-project.org>
Subject: Re: [PATCH] [RFC PATCH] ALSA: usb-audio: endpoint: Prevent NULL pointer deference in snd_usb_endpoint_close
In-Reply-To: <20240426122511.547755-1-quic_kuruva@quicinc.com>
References: <20240426122511.547755-1-quic_kuruva@quicinc.com>
User-Agent: Wanderlust/2.15.9 (Almost Unreal) Emacs/27.2 Mule/6.0
Precedence: bulk
MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue")
Content-Type: text/plain; charset=US-ASCII

On Fri, 26 Apr 2024 14:25:11 +0200,
Rajashekar kuruva wrote:
> 
> When multiple plug-in and plug-out events occur,
> there is a risk of encountering a NULL pointer dereference
> leading to a kernel panic during a headset use-case.
> this issue arises in the snd_usb_endpoint_close function

Such a scenario can't happen: ep->iface_ref is changed only in
chip->mutex lock, hence it can't be NULL there.


thanks,

Takashi