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From: Takashi Iwai <tiwai@suse.de>
To: Guangshuo Li <lgs201920130244@gmail.com>
Cc: Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
	Curtis Malainey <cujomalainey@chromium.org>,
	linux-sound@vger.kernel.org, linux-kernel@vger.kernel.org,
	stable@vger.kernel.org
Subject: Re: [PATCH] ALSA: hwdep: fix NULL dereference on error path
Date: Mon, 13 Apr 2026 07:22:45 +0200	[thread overview]
Message-ID: <87qzojwi1m.wl-tiwai@suse.de> (raw)
In-Reply-To: <20260412174529.2597250-1-lgs201920130244@gmail.com>

On Sun, 12 Apr 2026 19:45:29 +0200,
Guangshuo Li wrote:
> 
> snd_hwdep_new() allocates a hwdep instance first and then allocates
> hwdep->dev via snd_device_alloc().
> 
> When snd_device_alloc() fails, hwdep->dev remains NULL, because
> snd_device_alloc() clears *dev_p before attempting to allocate the
> device object. The error path then calls snd_hwdep_free(), which
> unconditionally invokes put_device(hwdep->dev).
> 
> This may lead to a NULL pointer dereference in put_device().

put_device() has a NULL check by itself, so it's safe to pass NULL
there.


thanks,

Takashi

  reply	other threads:[~2026-04-13  5:22 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-04-12 17:45 [PATCH] ALSA: hwdep: fix NULL dereference on error path Guangshuo Li
2026-04-13  5:22 ` Takashi Iwai [this message]
2026-04-13  5:48   ` Guangshuo Li

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