From: Michał Mirosław Date: Mon, 8 Jun 2020 16:50:39 +0000 (+0200) Subject: ALSA: pcm: disallow linking stream to itself X-Git-Tag: v5.6.19~89 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c8b0322b688fbbcb7eff739b95aa38d1a65db296;p=thirdparty%2Fkernel%2Fstable.git 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 Link: https://lore.kernel.org/r/89c4a2487609a0ed6af3ecf01cc972bdc59a7a2d.1591634956.git.mirq-linux@rere.qmqm.pl Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index d5443eeb8b633..59e1338f8170c 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -2163,6 +2163,12 @@ 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 = kzalloc(sizeof(*group), GFP_KERNEL); if (!group) { res = -ENOMEM;