[PATCH v2] ALSA: hda: Fix forget to free resource in error handling code path in hda_codec_driver_probe

[PATCH v2] ALSA: hda: Fix forget to free resource in error handling code path in hda_codec_driver_probe

[Wang YanQing]

When hda_codec_driver_probe meet error and return failure, we need
to free resource with patch_ops.free, or we will get resource leak.

Signed-off-by: Wang YanQing <udknight@gmail.com>
---
 Changes v1-v2:
 1: Fix calling patch_ops.free after module_put, reported by Takashi Iwai.

 Hi! Takashi Iwai
 Because the only one calling site of patch_ops.free is in
 hda_codec_driver_remove, and if hda_codec_driver_probe return
 failure, we will no chance to call the hda_codec_driver_remove,
 so I think we don't need to care below case:
 "Or, for safety, we may put an internal flag to indicate that the codec
  free got already called, and check it at before calling
  patch_ops.free, too."

 Thanks!

 sound/pci/hda/hda_bind.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/sound/pci/hda/hda_bind.c b/sound/pci/hda/hda_bind.c
index 6efadbf..d361bb7 100644
--- a/sound/pci/hda/hda_bind.c
+++ b/sound/pci/hda/hda_bind.c
@@ -100,7 +100,7 @@ static int hda_codec_driver_probe(struct device *dev)
 	if (patch) {
 		err = patch(codec);
 		if (err < 0)
-			goto error_module;
+			goto error_module_put;
 	}
 
 	err = snd_hda_codec_build_pcms(codec);
@@ -120,6 +120,9 @@ static int hda_codec_driver_probe(struct device *dev)
 	return 0;
 
  error_module:
+	if (codec->patch_ops.free)
+		codec->patch_ops.free(codec);
+ error_module_put:
 	module_put(owner);
 
  error:
-- 
1.8.5.6.2.g3d8a54e.dirty

Re: [PATCH v2] ALSA: hda: Fix forget to free resource in error handling code path in hda_codec_driver_probe

[Takashi Iwai]

On Mon, 04 Sep 2017 17:17:09 +0200,
Wang YanQing wrote:
> 
> When hda_codec_driver_probe meet error and return failure, we need
> to free resource with patch_ops.free, or we will get resource leak.
> 
> Signed-off-by: Wang YanQing <udknight@gmail.com>
> ---
>  Changes v1-v2:
>  1: Fix calling patch_ops.free after module_put, reported by Takashi Iwai.
> 
>  Hi! Takashi Iwai
>  Because the only one calling site of patch_ops.free is in
>  hda_codec_driver_remove, and if hda_codec_driver_probe return
>  failure, we will no chance to call the hda_codec_driver_remove,
>  so I think we don't need to care below case:
>  "Or, for safety, we may put an internal flag to indicate that the codec
>   free got already called, and check it at before calling
>   patch_ops.free, too."

Fair enough, applied now.

I found patch_ca0132.c still misses the free at the error path in its
probe function, so I'll fix it.

thanks,

Takashi