Commit 75e93e7b authored Aug 22, 2021 by Ray Essick

Avoid returning value on stack

AMediaFormat_getString() returnes a string not guaranteed to live beyond
the call. The underlying implementation of String8 seems to have made
this safe by using SharedBuffers, but that's luck of the implementatoon,
not a guarantee of the API.  We instead get our value by chasing through
where we just added it to the longer-lived vector.

Bug: 193904641
Test: atest libmedkandk_test
Test: atest android.mediav2.cts.MediaFormatUnitTest (master)
Change-Id: I7df35b7dbccf24c72cfd977a6b13d85aee8ae555

parent 1c3c35c0

media/ndk/NdkMediaFormat.cpp

+5 −2

Original line number	Diff line number	Diff line
		@@ -200,8 +200,11 @@ bool AMediaFormat_getString(AMediaFormat* mData, const char name, const char *
		AString tmp;
		if (mData->mFormat->findString(name, &tmp)) {
		String8 ret(tmp.c_str());
		mData->mStringCache.add(String8(name), ret);
		*out = ret.string();
		ssize_t i = mData->mStringCache.add(String8(name), ret);
		if (i < 0) {
		return false;
		}
		*out = mData->mStringCache.valueAt(i).string();
		return true;
		}
		return false;