avcodec/rasc: Fix off by 1 error in vertical coordinate
authorMichael Niedermayer <michael@niedermayer.cc>
Tue, 2 Oct 2018 01:04:51 +0000 (03:04 +0200)
committerMichael Niedermayer <michael@niedermayer.cc>
Wed, 3 Oct 2018 09:14:17 +0000 (11:14 +0200)
Fixes: out of array read
Fixes: 10311/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_RASC_fuzzer-4856330905452544

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
libavcodec/rasc.c

index fbbb134..eb02168 100644 (file)
@@ -272,9 +272,9 @@ static int decode_move(AVCodecContext *avctx,
         if (!s->frame2->data[0] || !s->frame1->data[0])
             return AVERROR_INVALIDDATA;
 
-        b1 = s->frame1->data[0] + s->frame1->linesize[0] * (start_y + h) + start_x * s->bpp;
-        b2 = s->frame2->data[0] + s->frame2->linesize[0] * (start_y + h) + start_x * s->bpp;
-        e2 = s->frame2->data[0] + s->frame2->linesize[0] * (mov_y + h) + mov_x * s->bpp;
+        b1 = s->frame1->data[0] + s->frame1->linesize[0] * (start_y + h - 1) + start_x * s->bpp;
+        b2 = s->frame2->data[0] + s->frame2->linesize[0] * (start_y + h - 1) + start_x * s->bpp;
+        e2 = s->frame2->data[0] + s->frame2->linesize[0] * (mov_y + h - 1) + mov_x * s->bpp;
 
         if (type == 2) {
             for (int j = 0; j < h; j++) {