Re: [PATCH] sound: hdmi: avoid dereferencing uninitialized 'jack' pointer

From: Arnd Bergmann
Date: Wed Feb 17 2016 - 04:41:35 EST


On Wednesday 17 February 2016 10:35:40 Takashi Iwai wrote:
> From: Takashi Iwai <tiwai@xxxxxxx>
> Subject: [PATCH v2] ALSA: jack: Allow building the jack layer without
> input device
>
> Since the recent integration of kctl jack and input jack layers, we
> can basically build the jack layer even without input devices. That
> is, the jack layer itself can be built with conditional to enable the
> input device support or not, while the users may enable always
> CONFIG_SND_JACK unconditionally.
>
> For achieving it, this patch changes the following:
> - A new Kconfig, CONFIG_SND_JACK_INPUT_DEV, was introduced to indicate
> whether the jack layer supports the input device,
> - A few items in snd_jack struct and relevant codes are conditionally
> built upon CONFIG_SND_JACK_INPUT_DEV,
> - The users of CONFIG_SND_JACK drop the messy dependency on
> CONFIG_INPUT.
>
> This change also automagically fixes a potential bug in HD-audio
> driver Arnd reported, where the NULL or uninitialized jack instance is
> dereferenced.
>
> Reported-by: Arnd Bergmann <arnd@xxxxxxxx>
> Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
>

Looks great, that indeed takes care of the issue I reported and
makes the code more useful and more robust overall.

Acked-by: Arnd Bergmann <arnd@xxxxxxxx>