[PATCH] ASoC: wm_adsp: Use scnprintf() for the limited buffer output

[PATCH] ASoC: wm_adsp: Use scnprintf() for the limited buffer output

[Takashi Iwai]

snprintf() is a hard-to-use function, it's especially difficult to use
it for concatenating substrings in a buffer with a limited size.
Since snprintf() returns the would-be-output size, not the actual
size, the subsequent use of snprintf() may point to the incorrect
position.

Use scnprintf() instead for fixing such potential errors.

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

diff --git a/sound/soc/codecs/wm_adsp.c b/sound/soc/codecs/wm_adsp.c
index d3d32b501aca..ffb9836e0538 100644
--- a/sound/soc/codecs/wm_adsp.c
+++ b/sound/soc/codecs/wm_adsp.c
@@ -1436,12 +1436,12 @@ static int wm_adsp_create_control(struct wm_adsp *dsp,
 		subname = NULL; /* don't append subname */
 		break;
 	case 2:
-		ret = snprintf(name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN,
+		ret = scnprintf(name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN,
 				"%s%c %.12s %x", dsp->name, *region_name,
 				wm_adsp_fw_text[dsp->fw], alg_region->alg);
 		break;
 	default:
-		ret = snprintf(name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN,
+		ret = scnprintf(name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN,
 				"%s %.12s %x", dsp->name,
 				wm_adsp_fw_text[dsp->fw], alg_region->alg);
 		break;
-- 
2.16.4

Re: [PATCH] ASoC: wm_adsp: Use scnprintf() for the limited buffer output

[Charles Keepax]

On Fri, Mar 13, 2020 at 02:03:34PM +0100, Takashi Iwai wrote:
> snprintf() is a hard-to-use function, it's especially difficult to use
> it for concatenating substrings in a buffer with a limited size.
> Since snprintf() returns the would-be-output size, not the actual
> size, the subsequent use of snprintf() may point to the incorrect
> position.
> 
> Use scnprintf() instead for fixing such potential errors.
> 
> Signed-off-by: Takashi Iwai <tiwai@suse.de>
> ---

Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>

Thanks,
Charles

Applied "ASoC: wm_adsp: Use scnprintf() for the limited buffer output" to the asoc tree

[Mark Brown]

The patch

   ASoC: wm_adsp: Use scnprintf() for the limited buffer output

has been applied to the asoc tree at

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git 

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.  

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

From 578194290d0bf85b087e73e35ea74574012cfd96 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Fri, 13 Mar 2020 14:03:34 +0100
Subject: [PATCH] ASoC: wm_adsp: Use scnprintf() for the limited buffer output

snprintf() is a hard-to-use function, it's especially difficult to use
it for concatenating substrings in a buffer with a limited size.
Since snprintf() returns the would-be-output size, not the actual
size, the subsequent use of snprintf() may point to the incorrect
position.

Use scnprintf() instead for fixing such potential errors.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20200313130334.9028-1-tiwai@suse.de
Signed-off-by: Mark Brown <broonie@kernel.org>
---
 sound/soc/codecs/wm_adsp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/soc/codecs/wm_adsp.c b/sound/soc/codecs/wm_adsp.c
index 2a9b610f6d43..9e5b6c4ac475 100644
--- a/sound/soc/codecs/wm_adsp.c
+++ b/sound/soc/codecs/wm_adsp.c
@@ -1432,12 +1432,12 @@ static int wm_adsp_create_control(struct wm_adsp *dsp,
 		subname = NULL; /* don't append subname */
 		break;
 	case 2:
-		ret = snprintf(name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN,
+		ret = scnprintf(name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN,
 				"%s%c %.12s %x", dsp->name, *region_name,
 				wm_adsp_fw_text[dsp->fw], alg_region->alg);
 		break;
 	default:
-		ret = snprintf(name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN,
+		ret = scnprintf(name, SNDRV_CTL_ELEM_ID_NAME_MAXLEN,
 				"%s %.12s %x", dsp->name,
 				wm_adsp_fw_text[dsp->fw], alg_region->alg);
 		break;
-- 
2.20.1