Messages in this thread | | | Date | Tue, 09 Feb 2016 22:56:39 +0100 | From | Takashi Iwai <> | Subject | Re: Should snd_card_free() check for null pointer? |
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On Tue, 09 Feb 2016 15:30:16 +0100, Jerome Marchand wrote: > > Hi, > > Before commit f24640648186b (ALSA: Use standard device refcount for card > accounting), snd_card_free() would return -EINVAL on a null pointer. Now > it ends up in a null pointer dereference. There is at least one driver > that can call snd_card_free() with null argument: saa7134_alsa. It can > easily be triggered by just inserting and removing the module (no need > to have the hardware). > I don't think that is a rule, but it seems that the standard behavior of > *_free() functions is to check for null pointer. What do you think?
Well, I have a mixed feeling about this. Allowing NULL sometimes makes the code easier. OTOH, caling snd_card_free() with NULL is really an unexpected situation, and if a driver does it, most likely it does something weird.
So, at this moment, I would fix the caller side. But, it's not a final call, just my gut feeling.
thanks,
Takashi
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