Re: sound/pci/hda/patch_ca0132.c: potential null dereference 'dma_engine'

[Takashi Iwai <tiwai@suse.de>]

At Fri, 21 Sep 2012 18:22:42 +0800,
Fengguang Wu wrote:
> 
> Hi Ian,
> 
> FYI, there are new smatch warnings show up in
> 
> commit 0b37d4c7982442730061a737c16939e8cc363861
> Author:     Ian Minett <ian_minett@creativelabs.com>
> Commit:     Takashi Iwai <tiwai@suse.de>
> CommitDate: Fri Sep 21 09:54:29 2012 +0200
> 
> + sound/pci/hda/patch_ca0132.c:2056 dspxfr_image() error: potential null dereference 'dma_engine'.  (kzalloc returns null)
> + sound/pci/hda/patch_ca0132.c:2056 dspxfr_image() error: we previously assumed 'dma_engine' could be null (see line 1963)

Fixed with the patch below.  Thanks!


Takashi

=Subject: [PATCH] ALSA: hda - Fix NULL dereference in error path of patch_ca0132.c

Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 sound/pci/hda/patch_ca0132.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/sound/pci/hda/patch_ca0132.c b/sound/pci/hda/patch_ca0132.c
index 5c6a056..03f57c9 100644
--- a/sound/pci/hda/patch_ca0132.c
+++ b/sound/pci/hda/patch_ca0132.c
@@ -1960,10 +1960,8 @@ static int dspxfr_image(struct hda_codec *codec,
 		return -EINVAL;
 
 	dma_engine = kzalloc(sizeof(*dma_engine), GFP_KERNEL);
-	if (!dma_engine) {
-		status = -ENOMEM;
-		goto exit;
-	}
+	if (!dma_engine)
+		return -ENOMEM;
 	memset((void *)dma_engine, 0, sizeof(*dma_engine));
 
 	dma_engine->dmab = kzalloc(sizeof(*dma_engine->dmab), GFP_KERNEL);
-- 
1.7.11.5