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authorTakashi Iwai <tiwai@suse.de>2018-01-05 16:09:47 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-01-17 09:38:51 +0100
commit01046dd834ac5ecf3c57dc34b60de127e7ac2d29 (patch)
tree7087bdc7d24187e973855652d1c3f65ca2e70852 /sound
parentbee3f2d5c02aed452542fae2bb980f555dd887ad (diff)
ALSA: aloop: Release cable upon open error path
commit 9685347aa0a5c2869058ca6ab79fd8e93084a67f upstream. The aloop runtime object and its assignment in the cable are left even when opening a substream fails. This doesn't mean any memory leak, but it still keeps the invalid pointer that may be referred by the another side of the cable spontaneously, which is a potential Oops cause. Clean up the cable assignment and the empty cable upon the error path properly. Fixes: 597603d615d2 ("ALSA: introduce the snd-aloop module for the PCM loopback") Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'sound')
-rw-r--r--sound/drivers/aloop.c38
1 files changed, 25 insertions, 13 deletions
diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c
index 54f348a4fb78..2adc88d6d507 100644
--- a/sound/drivers/aloop.c
+++ b/sound/drivers/aloop.c
@@ -658,12 +658,31 @@ static int rule_channels(struct snd_pcm_hw_params *params,
return snd_interval_refine(hw_param_interval(params, rule->var), &t);
}
+static void free_cable(struct snd_pcm_substream *substream)
+{
+ struct loopback *loopback = substream->private_data;
+ int dev = get_cable_index(substream);
+ struct loopback_cable *cable;
+
+ cable = loopback->cables[substream->number][dev];
+ if (!cable)
+ return;
+ if (cable->streams[!substream->stream]) {
+ /* other stream is still alive */
+ cable->streams[substream->stream] = NULL;
+ } else {
+ /* free the cable */
+ loopback->cables[substream->number][dev] = NULL;
+ kfree(cable);
+ }
+}
+
static int loopback_open(struct snd_pcm_substream *substream)
{
struct snd_pcm_runtime *runtime = substream->runtime;
struct loopback *loopback = substream->private_data;
struct loopback_pcm *dpcm;
- struct loopback_cable *cable;
+ struct loopback_cable *cable = NULL;
int err = 0;
int dev = get_cable_index(substream);
@@ -682,7 +701,6 @@ static int loopback_open(struct snd_pcm_substream *substream)
if (!cable) {
cable = kzalloc(sizeof(*cable), GFP_KERNEL);
if (!cable) {
- kfree(dpcm);
err = -ENOMEM;
goto unlock;
}
@@ -724,6 +742,10 @@ static int loopback_open(struct snd_pcm_substream *substream)
else
runtime->hw = cable->hw;
unlock:
+ if (err < 0) {
+ free_cable(substream);
+ kfree(dpcm);
+ }
mutex_unlock(&loopback->cable_lock);
return err;
}
@@ -732,20 +754,10 @@ static int loopback_close(struct snd_pcm_substream *substream)
{
struct loopback *loopback = substream->private_data;
struct loopback_pcm *dpcm = substream->runtime->private_data;
- struct loopback_cable *cable;
- int dev = get_cable_index(substream);
loopback_timer_stop(dpcm);
mutex_lock(&loopback->cable_lock);
- cable = loopback->cables[substream->number][dev];
- if (cable->streams[!substream->stream]) {
- /* other stream is still alive */
- cable->streams[substream->stream] = NULL;
- } else {
- /* free the cable */
- loopback->cables[substream->number][dev] = NULL;
- kfree(cable);
- }
+ free_cable(substream);
mutex_unlock(&loopback->cable_lock);
return 0;
}