[FFmpeg-cvslog] avcodec/magicyuv: Check bits left in flags&1 branch

[Michael Niedermayer]

ffmpeg | branch: release/3.4 | Michael Niedermayer <michael at niedermayer.cc> | Sat Jun 23 23:37:10 2018 +0200| [d56eed37d195fe7b12ba3b00160032240cb06ea8] | committer: Michael Niedermayer

avcodec/magicyuv: Check bits left in flags&1 branch

Fixes: Timeout
Fixes: 8690/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MAGICYUV_fuzzer-6542020913922048

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Paul B Mahol <onemda at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 7719b8ccc790b6e1325af0afe2b65e2334a7173c)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d56eed37d195fe7b12ba3b00160032240cb06ea8
---

 libavcodec/magicyuv.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libavcodec/magicyuv.c b/libavcodec/magicyuv.c
index 3c1a89077b..cc1c63072b 100644
--- a/libavcodec/magicyuv.c
+++ b/libavcodec/magicyuv.c
@@ -240,6 +240,8 @@ static int magy_decode_slice10(AVCodecContext *avctx, void *tdata,
 
         dst = (uint16_t *)p->data[i] + j * sheight * stride;
         if (flags & 1) {
+            if (get_bits_left(&gb) < bps * width * height)
+                return AVERROR_INVALIDDATA;
             for (k = 0; k < height; k++) {
                 for (x = 0; x < width; x++)
                     dst[x] = get_bits(&gb, bps);
@@ -371,6 +373,8 @@ static int magy_decode_slice(AVCodecContext *avctx, void *tdata,
 
         dst = p->data[i] + j * sheight * stride;
         if (flags & 1) {
+            if (get_bits_left(&gb) < 8* width * height)
+                return AVERROR_INVALIDDATA;
             for (k = 0; k < height; k++) {
                 for (x = 0; x < width; x++)
                     dst[x] = get_bits(&gb, 8);