audio policy: fix inifinite loop in clearAudioPatches()

releaseAudioPatch() does not necessarily remove the audio patch
from the list.
Scan the list from the top down to avoid adjusting the index.

Bug: 18621514.
Change-Id: I58787154680f7cb1818509017835b1693d62190f

1 files changed, 2 insertions, 5 deletions

diff --git a/services/audiopolicy/AudioPolicyManager.cpp b/services/audiopolicy/AudioPolicyManager.cpp
index b5a3d5b..76acc41 100644
--- a/services/audiopolicy/AudioPolicyManager.cpp
+++ b/services/audiopolicy/AudioPolicyManager.cpp
@@ -2650,13 +2650,10 @@ status_t AudioPolicyManager::setAudioPortConfig(const struct audio_port_config *
 
 void AudioPolicyManager::clearAudioPatches(uid_t uid)
 {
-    for (ssize_t i = 0; i < (ssize_t)mAudioPatches.size(); i++)  {
+    for (ssize_t i = (ssize_t)mAudioPatches.size() - 1; i >= 0; i--)  {
         sp<AudioPatch> patchDesc = mAudioPatches.valueAt(i);
         if (patchDesc->mUid == uid) {
-            // releaseAudioPatch() removes the patch from mAudioPatches
-            if (releaseAudioPatch(mAudioPatches.keyAt(i), uid) == NO_ERROR) {
-                i--;
-            }
+            releaseAudioPatch(mAudioPatches.keyAt(i), uid);
         }
     }
 }