ssize_t MPEG4DataSource::readAt(off64_t offset, void *data, size_t size) {
 Mutex::Autolock autoLock(mLock);

 if (isInRange(mCachedOffset, mCachedSize, offset, size)) {
        memcpy(data, &mCache[offset - mCachedOffset], size);
 return size;
 }

 return mSource->readAt(offset, data, size);
}

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.