ALSA: pcm: disallow linking stream to itself

commit 951e2736f4b11b58dc44d41964fa17c3527d882a upstream.

Prevent SNDRV_PCM_IOCTL_LINK linking stream to itself - the code
can't handle it. Fixed commit is not where bug was introduced, but
changes the context significantly.

Cc: stable@vger.kernel.org
Fixes: 0888c321de70 ("pcm_native: switch to fdget()/fdput()")
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/89c4a2487609a0ed6af3ecf01cc972bdc59a7a2d.1591634956.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Michał Mirosław 2020-06-08 18:50:39 +02:00 committed by Greg Kroah-Hartman
parent 855995d68e
commit 496d422fcb

View File

@ -1836,6 +1836,11 @@ static int snd_pcm_link(struct snd_pcm_substream *substream, int fd)
}
pcm_file = f.file->private_data;
substream1 = pcm_file->substream;
if (substream == substream1) {
res = -EINVAL;
goto _badf;
}
group = kmalloc(sizeof(*group), GFP_KERNEL);
if (!group) {
res = -ENOMEM;