libstagefright: httplive: Add NULL check for empty playlist

If the source playlist is empty, the playlist meta will be NULL.
Check for this case to avoid an invalid dereference. Also flag
playlists without the required EXT-X-TARGETDURATION tag as malformed.

Bug: 18821145
Change-Id: Idf74d890a89bbc6483a6d4060eb092dc7461be24

1 files changed, 6 insertions, 1 deletions

diff --git a/media/libstagefright/httplive/PlaylistFetcher.cpp b/media/libstagefright/httplive/PlaylistFetcher.cpp
index d8eed5b..2cfdfe4 100644
--- a/media/libstagefright/httplive/PlaylistFetcher.cpp
+++ b/media/libstagefright/httplive/PlaylistFetcher.cpp
@@ -610,7 +610,12 @@ void PlaylistFetcher::onMonitorQueue() {
     int32_t targetDurationSecs;
     int64_t targetDurationUs = kMinBufferedDurationUs;
     if (mPlaylist != NULL) {
-        CHECK(mPlaylist->meta()->findInt32("target-duration", &targetDurationSecs));
+        if (mPlaylist->meta() == NULL || !mPlaylist->meta()->findInt32(
+                "target-duration", &targetDurationSecs)) {
+            ALOGE("Playlist is missing required EXT-X-TARGETDURATION tag");
+            notifyError(ERROR_MALFORMED);
+            return;
+        }
         targetDurationUs = targetDurationSecs * 1000000ll;
     }