From: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>
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@xxxxxxxxxxxxxxx
Fixes: 0888c321de70 ("pcm_native: switch to fdget()/fdput()")
Signed-off-by: Michał Mirosław <mirq-linux@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/89c4a2487609a0ed6af3ecf01cc972bdc59a7a2d.1591634956.git.mirq-linux@xxxxxxxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
Backported to 4.19.y. It can be used for older branches, too.
sound/core/pcm_native.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c
index 14b1ee29509d..071e09c3d855 100644
--- a/sound/core/pcm_native.c
+++ b/sound/core/pcm_native.c
@@ -1950,6 +1950,11 @@ 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;
--
2.16.4
