avcodec/truemotion2: Fix several integer overflows in tm2_motion_block()
authorMichael Niedermayer <michael@niedermayer.cc>
Mon, 8 Jul 2019 21:00:09 +0000 (23:00 +0200)
committerMichael Niedermayer <michael@niedermayer.cc>
Sun, 4 Aug 2019 19:16:28 +0000 (21:16 +0200)
Fixes: 15524/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TRUEMOTION2_fuzzer-5173148372172800
Fixes: signed integer overflow: 13701388 - -2134868270 cannot be represented in type 'int'

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 9a353ea8766206bd302f3f12ca1d226237542908)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
libavcodec/truemotion2.c

index a86dd16..5d6dfc2 100644 (file)
@@ -764,10 +764,10 @@ static inline void tm2_motion_block(TM2Context *ctx, AVFrame *pic, int bx, int b
     }
     /* calculate deltas */
     Y -= Ystride * 4;
-    ctx->D[0] = Y[3] - last[3];
-    ctx->D[1] = Y[3 + Ystride] - Y[3];
-    ctx->D[2] = Y[3 + Ystride * 2] - Y[3 + Ystride];
-    ctx->D[3] = Y[3 + Ystride * 3] - Y[3 + Ystride * 2];
+    ctx->D[0] = (unsigned)Y[3] - last[3];
+    ctx->D[1] = (unsigned)Y[3 + Ystride] - Y[3];
+    ctx->D[2] = (unsigned)Y[3 + Ystride * 2] - Y[3 + Ystride];
+    ctx->D[3] = (unsigned)Y[3 + Ystride * 3] - Y[3 + Ystride * 2];
     for (i = 0; i < 4; i++)
         last[i] = Y[i + Ystride * 3];
 }