Fix crash on malformed id3

Bug: 22954006
Change-Id: I488cb1e2c69fc7043b6040481b30fa866000515d
Tested-by: Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de>

3 files changed, 27 insertions, 13 deletions

diff --git a/include/media/stagefright/MetaData.h b/include/media/stagefright/MetaData.h
index e91904c..6249284 100644
--- a/include/media/stagefright/MetaData.h
+++ b/include/media/stagefright/MetaData.h
@@ -239,7 +239,7 @@ private:
             return mSize <= sizeof(u.reservoir);
         }
 
-        void allocateStorage(size_t size);
+        void *allocateStorage(size_t size);
         void freeStorage();
 
         void *storage() {
diff --git a/media/libstagefright/MetaData.cpp b/media/libstagefright/MetaData.cpp
index 642d15a..41d2b23 100644
--- a/media/libstagefright/MetaData.cpp
+++ b/media/libstagefright/MetaData.cpp
@@ -230,8 +230,11 @@ MetaData::typed_data::~typed_data() {
 MetaData::typed_data::typed_data(const typed_data &from)
     : mType(from.mType),
       mSize(0) {
-    allocateStorage(from.mSize);
-    memcpy(storage(), from.storage(), mSize);
+
+    void *dst = allocateStorage(from.mSize);
+    if (dst) {
+        memcpy(dst, from.storage(), mSize);
+    }
 }
 
 MetaData::typed_data &MetaData::typed_data::operator=(
@@ -239,8 +242,10 @@ MetaData::typed_data &MetaData::typed_data::operator=(
     if (this != &from) {
         clear();
         mType = from.mType;
-        allocateStorage(from.mSize);
-        memcpy(storage(), from.storage(), mSize);
+        void *dst = allocateStorage(from.mSize);
+        if (dst) {
+            memcpy(dst, from.storage(), mSize);
+        }
     }
 
     return *this;
@@ -257,13 +262,11 @@ void MetaData::typed_data::setData(
     clear();
 
     mType = type;
-    allocateStorage(size);
-    void *dst = storage();
-    if (!dst) {
-        ALOGE("Couldn't allocate %zu bytes for item", size);
-        return;
+
+    void *dst = allocateStorage(size);
+    if (dst) {
+        memcpy(dst, data, size);
     }
-    memcpy(dst, data, size);
 }
 
 void MetaData::typed_data::getData(
@@ -273,14 +276,19 @@ void MetaData::typed_data::getData(
     *data = storage();
 }
 
-void MetaData::typed_data::allocateStorage(size_t size) {
+void *MetaData::typed_data::allocateStorage(size_t size) {
     mSize = size;
 
     if (usesReservoir()) {
-        return;
+        return &u.reservoir;
     }
 
     u.ext_data = malloc(mSize);
+    if (u.ext_data == NULL) {
+        ALOGE("Couldn't allocate %zu bytes for item", size);
+        mSize = 0;
+    }
+    return u.ext_data;
 }
 
 void MetaData::typed_data::freeStorage() {
diff --git a/media/libstagefright/id3/ID3.cpp b/media/libstagefright/id3/ID3.cpp
index 22c2f5a..93176c5 100644
--- a/media/libstagefright/id3/ID3.cpp
+++ b/media/libstagefright/id3/ID3.cpp
@@ -776,6 +776,12 @@ ID3::getAlbumArt(size_t *length, String8 *mime) const {
 
             size_t descLen = StringSize(&data[2 + mimeLen], encoding);
 
+            if (size < 2 ||
+                    size - 2 < mimeLen ||
+                    size - 2 - mimeLen < descLen) {
+                ALOGW("bogus album art sizes");
+                return NULL;
+            }
             *length = size - 2 - mimeLen - descLen;
 
             return &data[2 + mimeLen + descLen];