staging: greybus: audio: fix uninitialized value issue

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@canonical.com>
Signed-off-by: Vaibhav Agarwal <vaibhav.sr@gmail.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/bc4f29eb502ccf93cd2ffd98db0e319fa7d0f247.1597408126.git.vaibhav.sr@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/greybus/audio_topology.c b/drivers/staging/greybus/audio_topology.c
index 2f9fdbd..83b38ae 100644 (file)
--- a/drivers/staging/greybus/audio_topology.c
+++ b/drivers/staging/greybus/audio_topology.c
@@ -456,6 +456,15 @@ 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)
+               goto exit;
+
        /* update ucontrol */
        if (gbvalue.value.integer_value[0] != val) {
                for (wi = 0; wi < wlist->num_widgets; wi++) {
@@ -466,25 +475,17 @@ 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,
-                                           __func__, kcontrol->id.name);
-                       return ret;
-               }
        }
 
-       return 0;
+exit:
+       gb_pm_runtime_put_autosuspend(bundle);
+       if (ret)
+               dev_err_ratelimited(codec_dev, "%d:Error in %s for %s\n", ret,
+                                   __func__, kcontrol->id.name);
+       return ret;
 }
 
 #define SOC_DAPM_MIXER_GB(xname, kcount, data) \