[PATCH v2] staging: greybus: audio: fix uninitialized value issue

[Vaibhav Agarwal]

The current implementation for gbcodec_mixer_dapm_ctl_put() uses
uninitialized gbvalue for comparison with updated value. This was found
using static analysis with coverity.

Uninitialized scalar variable (UNINIT)
11. uninit_use: Using uninitialized value
gbvalue.value.integer_value[0].
460        if (gbvalue.value.integer_value[0] != val) {

This patch fixes the issue with fetching the gbvalue before using it for
    comparision.

Fixes: 6339d2322c47 ("greybus: audio: Add topology parser for GB codec")
Reported-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Signed-off-by: Vaibhav Agarwal <vaibhav.sr@xxxxxxxxx>
---
Changelog:
v2: Fix the missing check for return value after get_control.
---
 drivers/staging/greybus/audio_topology.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/greybus/audio_topology.c b/drivers/staging/greybus/audio_topology.c
index 2f9fdbdcd547..9f98691b2f5f 100644
--- a/drivers/staging/greybus/audio_topology.c
+++ b/drivers/staging/greybus/audio_topology.c
@@ -456,6 +456,18 @@ static int gbcodec_mixer_dapm_ctl_put(struct snd_kcontrol *kcontrol,
 	val = ucontrol->value.integer.value[0] & mask;
 	connect = !!val;
 
+	ret = gb_pm_runtime_get_sync(bundle);
+	if (ret)
+		return ret;
+
+	ret = gb_audio_gb_get_control(module->mgmt_connection, data->ctl_id,
+				      GB_AUDIO_INVALID_INDEX, &gbvalue);
+	if (ret) {
+		dev_err_ratelimited(codec_dev, "%d:Error in %s for %s\n", ret,
+				    __func__, kcontrol->id.name);
+		return ret;
+	}
+
 	/* update ucontrol */
 	if (gbvalue.value.integer_value[0] != val) {
 		for (wi = 0; wi < wlist->num_widgets; wi++) {
@@ -466,16 +478,10 @@ static int gbcodec_mixer_dapm_ctl_put(struct snd_kcontrol *kcontrol,
 		gbvalue.value.integer_value[0] =
 			cpu_to_le32(ucontrol->value.integer.value[0]);
 
-		ret = gb_pm_runtime_get_sync(bundle);
-		if (ret)
-			return ret;
-
 		ret = gb_audio_gb_set_control(module->mgmt_connection,
 					      data->ctl_id,
 					      GB_AUDIO_INVALID_INDEX, &gbvalue);
 
-		gb_pm_runtime_put_autosuspend(bundle);
-
 		if (ret) {
 			dev_err_ratelimited(codec_dev,
 					    "%d:Error in %s for %s\n", ret,
@@ -483,6 +489,7 @@ static int gbcodec_mixer_dapm_ctl_put(struct snd_kcontrol *kcontrol,
 			return ret;
 		}
 	}
+	gb_pm_runtime_put_autosuspend(bundle);
 
 	return 0;
 }

base-commit: fc80c51fd4b23ec007e88d4c688f2cac1b8648e7
-- 
2.27.0