ALSA: usb-audio: fix rate_list memory leak

The array of sample rates is reallocated every time when opening
the PCM device, but was freed only once when unplugging the device.

Reported-by: "Alexander E. Patrakov" <patrakov@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 3 insertions, 0 deletions

diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 24839d932648..cdf8b7601973 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -788,6 +788,9 @@ static int snd_usb_pcm_check_knot(struct snd_pcm_runtime *runtime,
         int count = 0, needs_knot = 0;
         int err;
 
+        kfree(subs->rate_list.list);
+        subs->rate_list.list = NULL;
+
         list_for_each_entry(fp, &subs->fmt_list, list) {
                 if (fp->rates & SNDRV_PCM_RATE_CONTINUOUS)
                         return 0;