[Line6linux-devel] [PATCH 1/5] staging: line6: fix memory leak in .hw_params()

[<ste...@gm...>]

From: Stefan Hajnoczi <ste...@gm...>

The .hw_params() pcm callback can be invoked multiple times in a row.
Ensure that the URB data buffer is only allocated once.

Signed-off-by: Stefan Hajnoczi <ste...@gm...>
---
 capture.c  |    7 +++++--
 playback.c |    7 +++++--
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/capture.c b/capture.c
index d9da7ed..c7e3bfa 100644
--- a/capture.c
+++ b/capture.c
@@ -320,8 +320,11 @@ static int snd_line6_capture_hw_params(struct snd_pcm_substream *substream,
 	}
 	/* -- [FD] end */
 
-	line6pcm->buffer_in = kmalloc(LINE6_ISO_BUFFERS * LINE6_ISO_PACKETS *
-				      line6pcm->max_packet_size, GFP_KERNEL);
+	/* We may be invoked multiple times in a row so allocate once only */
+	if (!line6pcm->buffer_in)
+		line6pcm->buffer_in =
+			kmalloc(LINE6_ISO_BUFFERS * LINE6_ISO_PACKETS *
+				line6pcm->max_packet_size, GFP_KERNEL);
 
 	if (!line6pcm->buffer_in) {
 		dev_err(line6pcm->line6->ifcdev,
diff --git a/playback.c b/playback.c
index b344527..c39d1f0 100644
--- a/playback.c
+++ b/playback.c
@@ -470,8 +470,11 @@ static int snd_line6_playback_hw_params(struct snd_pcm_substream *substream,
 	}
 	/* -- [FD] end */
 
-	line6pcm->buffer_out = kmalloc(LINE6_ISO_BUFFERS * LINE6_ISO_PACKETS *
-				       line6pcm->max_packet_size, GFP_KERNEL);
+	/* We may be invoked multiple times in a row so allocate once only */
+	if (!line6pcm->buffer_out)
+		line6pcm->buffer_out =
+			kmalloc(LINE6_ISO_BUFFERS * LINE6_ISO_PACKETS *
+				line6pcm->max_packet_size, GFP_KERNEL);
 
 	if (!line6pcm->buffer_out) {
 		dev_err(line6pcm->line6->ifcdev,
-- 
1.7.7.3