[PATCH] ASoC: dapm: Fix uninitialized variable in snd_soc_dapm_get_enum_double()

[PATCH] ASoC: dapm: Fix uninitialized variable in snd_soc_dapm_get_enum_double()

[Geert Uytterhoeven]

If soc_dapm_read() fails, reg_val will be uninitialized, and bogus
values will be written later:

sound/soc/soc-dapm.c: In function 'snd_soc_dapm_get_enum_double':
sound/soc/soc-dapm.c:2862:15: warning: 'reg_val' may be used uninitialized in this function [-Wmaybe-uninitialized]
  unsigned int reg_val, val;
               ^

Return early on error to fix this.

Introduced by commit ce0fc93ae56e2ba50ff8c220d69e4e860e889320 ("ASoC:
Add DAPM support at the component level").
---
Is this correct? Please review.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 sound/soc/soc-dapm.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c
index 8348352dc2c6..177bd8639ef9 100644
--- a/sound/soc/soc-dapm.c
+++ b/sound/soc/soc-dapm.c
@@ -2860,12 +2860,14 @@ int snd_soc_dapm_get_enum_double(struct snd_kcontrol *kcontrol,
 	struct snd_soc_dapm_context *dapm = snd_soc_dapm_kcontrol_dapm(kcontrol);
 	struct soc_enum *e = (struct soc_enum *)kcontrol->private_value;
 	unsigned int reg_val, val;
-	int ret = 0;
 
-	if (e->reg != SND_SOC_NOPM)
-		ret = soc_dapm_read(dapm, e->reg, &reg_val);
-	else
+	if (e->reg != SND_SOC_NOPM) {
+		int ret = soc_dapm_read(dapm, e->reg, &reg_val);
+		if (ret)
+			return ret;
+	} else {
 		reg_val = dapm_kcontrol_get_value(kcontrol);
+	}
 
 	val = (reg_val >> e->shift_l) & e->mask;
 	ucontrol->value.enumerated.item[0] = snd_soc_enum_val_to_item(e, val);
@@ -2875,7 +2877,7 @@ int snd_soc_dapm_get_enum_double(struct snd_kcontrol *kcontrol,
 		ucontrol->value.enumerated.item[1] = val;
 	}
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(snd_soc_dapm_get_enum_double);
 
-- 
1.9.1

Re: [PATCH] ASoC: dapm: Fix uninitialized variable in snd_soc_dapm_get_enum_double()

[Lars-Peter Clausen]

On 08/08/2014 05:29 PM, Geert Uytterhoeven wrote:
> If soc_dapm_read() fails, reg_val will be uninitialized, and bogus
> values will be written later:
>
> sound/soc/soc-dapm.c: In function 'snd_soc_dapm_get_enum_double':
> sound/soc/soc-dapm.c:2862:15: warning: 'reg_val' may be used uninitialized in this function [-Wmaybe-uninitialized]
>    unsigned int reg_val, val;
>                 ^
>
> Return early on error to fix this.
>
> Introduced by commit ce0fc93ae56e2ba50ff8c220d69e4e860e889320 ("ASoC:
> Add DAPM support at the component level").
> ---
> Is this correct? Please review.

Yes, thanks.

Acked-by: Lars-Peter Clausen <lars@metafoo.de>

>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

Re: [PATCH] ASoC: dapm: Fix uninitialized variable in snd_soc_dapm_get_enum_double()

[Mark Brown]

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On Fri, Aug 08, 2014 at 05:29:35PM +0200, Geert Uytterhoeven wrote:
> If soc_dapm_read() fails, reg_val will be uninitialized, and bogus
> values will be written later:

Applied, thanks.

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Re: [PATCH] ASoC: dapm: Fix uninitialized variable in snd_soc_dapm_get_enum_double()

[Mark Brown]

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On Fri, Aug 08, 2014 at 05:29:35PM +0200, Geert Uytterhoeven wrote:

> ---
> Is this correct? Please review.
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

BTW please remember to put the signoff *before* the --- otherwise it
gets discarded.

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