Fix integer overflow in time conversion
Converting unix epoch time to mpeg4 time requires adding over 2B seconds,
which caused an overflow in a calculation involving time_t, which is signed.
Bug: 23574783
Change-Id: I21bacc9f5a422091f3c903fb8cf1c760fc078953
diff --git a/media/libstagefright/MPEG4Writer.cpp b/media/libstagefright/MPEG4Writer.cpp
index 844a019..6b26908 100644
--- a/media/libstagefright/MPEG4Writer.cpp
+++ b/media/libstagefright/MPEG4Writer.cpp
@@ -938,7 +938,11 @@
// MP4 file uses time counting seconds since midnight, Jan. 1, 1904
// while time function returns Unix epoch values which starts
// at 1970-01-01. Lets add the number of seconds between them
- uint32_t mpeg4Time = now + (66 * 365 + 17) * (24 * 60 * 60);
+ static const uint32_t delta = (66 * 365 + 17) * (24 * 60 * 60);
+ if (now < 0 || uint32_t(now) > UINT32_MAX - delta) {
+ return 0;
+ }
+ uint32_t mpeg4Time = uint32_t(now) + delta;
return mpeg4Time;
}