2022-01-26 22:27:27

by Tom Rix

Subject: [PATCH] ALSA: usb-audio: initialize variables that could ignore errors

From: Tom Rix <[email protected]>

clang static analysis reports this representative issue
mixer.c:1548:35: warning: Assigned value is garbage or undefined
ucontrol->value.integer.value[0] = val;
^ ~~~

The filter_error() macro allows errors to be ignored.
If errors can be ignored, initialize variables
so garbage will not be used.

Fixes: 48cc42973509 ("ALSA: usb-audio: Filter error from connector kctl ops, too")
Signed-off-by: Tom Rix <[email protected]>
---
sound/usb/mixer.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index e8f3f8d622ec5..630766ba259fd 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -1527,6 +1527,10 @@ static int get_connector_value(struct usb_mixer_elem_info *cval,
usb_audio_err(chip,
"cannot get connectors status: req = %#x, wValue = %#x, wIndex = %#x, type = %d\n",
UAC_GET_CUR, validx, idx, cval->val_type);
+
+ if (val)
+ *val = 0;
+
return filter_error(cval, ret);
}

--
2.26.3

2022-01-28 02:57:30

by Takashi Iwai

Subject: Re: [PATCH] ALSA: usb-audio: initialize variables that could ignore errors

On Wed, 26 Jan 2022 19:21:42 +0100,
[email protected] wrote:
>
> From: Tom Rix <[email protected]>
>
> clang static analysis reports this representative issue
> mixer.c:1548:35: warning: Assigned value is garbage or undefined
> ucontrol->value.integer.value[0] = val;
> ^ ~~~
>
> The filter_error() macro allows errors to be ignored.
> If errors can be ignored, initialize variables
> so garbage will not be used.
>
> Fixes: 48cc42973509 ("ALSA: usb-audio: Filter error from connector kctl ops, too")
> Signed-off-by: Tom Rix <[email protected]>

Thanks, applied.


Takashi