Commit d10ee9c5 authored Jul 20, 2018 by Srikanth K H Committed by Takashi Iwai Jul 22, 2018

ALSA: timer: catch invalid timer object creation



A timer object for the classes SNDRV_TIMER_CLASS_CARD and
SNDRV_TIMER_CLASS_PCM has to be associated with a card object, but we
have no check at creation time.  Such a timer object with NULL card
causes various unexpected problems, e.g. NULL dereference at reading
the sound timer proc file.

So as preventive measure while the creating the sound timer object is
created the card information availability is checked for the mentioned
entries and returned error if its NULL.

Signed-off-by: Srikanth K H <srikanth.h@samsung.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

parent 7abeb64d

sound/core/timer.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -883,6 +883,11 @@ int snd_timer_new(struct snd_card card, char id, struct snd_timer_id *tid,

		if (snd_BUG_ON(!tid))
		return -EINVAL;
		if (tid->dev_class == SNDRV_TIMER_CLASS_CARD \|\|
		tid->dev_class == SNDRV_TIMER_CLASS_PCM) {
		if (WARN_ON(!card))
		return -EINVAL;
		}
		if (rtimer)
		*rtimer = NULL;
		timer = kzalloc(sizeof(*timer), GFP_KERNEL);

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