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From: Jerome Marchand <jmarchan@redhat.com>
To: Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>
Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org
Subject: Should snd_card_free() check for null pointer?
Date: Tue, 9 Feb 2016 15:30:16 +0100	[thread overview]
Message-ID: <56B9F7F8.1000605@redhat.com> (raw)

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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?

Thanks,
Jerome


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             reply	other threads:[~2016-02-09 14:30 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-09 14:30 Jerome Marchand [this message]
2016-02-09 21:56 ` Should snd_card_free() check for null pointer? Takashi Iwai
2016-02-09 21:56   ` Takashi Iwai
2016-02-10  7:41   ` Jerome Marchand
2016-02-10  7:41     ` Jerome Marchand
2016-02-10  8:45     ` Takashi Iwai

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