[alsa-devel] [PATCH] sound: hdmi: avoid dereferencing uninitialized 'jack' pointer

[Arnd Bergmann]

On Wednesday 17 February 2016 10:35:40 Takashi Iwai wrote:
> From: Takashi Iwai <tiwai at suse.de>
> 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 at arndb.de>
> Signed-off-by: Takashi Iwai <tiwai at suse.de>
> 

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 at arndb.de>