avcodec/bink: Fix integer overflow in unquantize_dct_coeffs()

Fixes: signed integer overflow: -3447 * 2883584 cannot be represented in type 'int'
Fixes: 15265/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_BINK_fuzzer-5088311799971840
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Peter Ross <pross@xvid.org>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

diff --git a/libavcodec/bink.c b/libavcodec/bink.c
index 8392bbeeb01d564bbd3f3d032e10616b18611e3b..d18c0ceae4cdca939d5fc3d144e453bc5e81a56c 100644 (file)
--- a/libavcodec/bink.c
+++ b/libavcodec/bink.c
@@ -702,15 +702,15 @@ static int read_dct_coeffs(BinkContext *c, GetBitContext *gb, int32_t block[64],
     return quant_idx;
 }
 
-static void unquantize_dct_coeffs(int32_t block[64], const int32_t quant[64],
+static void unquantize_dct_coeffs(int32_t block[64], const uint32_t quant[64],
                                   int coef_count, int coef_idx[64],
                                   const uint8_t *scan)
 {
     int i;
-    block[0] = (block[0] * quant[0]) >> 11;
+    block[0] = (int)(block[0] * quant[0]) >> 11;
     for (i = 0; i < coef_count; i++) {
         int idx = coef_idx[i];
-        block[scan[idx]] = (block[scan[idx]] * quant[idx]) >> 11;
+        block[scan[idx]] = (int)(block[scan[idx]] * quant[idx]) >> 11;
     }
 }