avcodec/flacdec: Fix overflow in multiplication in decode_subframe_fixed()
authorMichael Niedermayer <michael@niedermayer.cc>
Tue, 26 Dec 2017 22:24:44 +0000 (23:24 +0100)
committerMichael Niedermayer <michael@niedermayer.cc>
Mon, 8 Jan 2018 22:19:14 +0000 (23:19 +0100)
Fixes: signed integer overflow: 2 * 1629495328 cannot be represented in type 'int'
Fixes: 4716/clusterfuzz-testcase-minimized-5835915940331520

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 3d23f7a0969bf76ad6dcdc2c4a5cd3ae884745a8)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
libavcodec/flacdec.c

index f552bbb..f95f795 100644 (file)
@@ -287,7 +287,7 @@ static int decode_subframe_fixed(FLACContext *s, int32_t *decoded,
     if (pred_order > 2)
         c = b - decoded[pred_order-2] + decoded[pred_order-3];
     if (pred_order > 3)
-        d = c - decoded[pred_order-2] + 2*decoded[pred_order-3] - decoded[pred_order-4];
+        d = c - decoded[pred_order-2] + 2U*decoded[pred_order-3] - decoded[pred_order-4];
 
     switch (pred_order) {
     case 0: