[FFmpeg-cvslog] avcodec/exr: Check line size for overflow

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Sep 26 22:04:16 2020 +0200| [9b72cea4463dd2fabcd9ba1454a0855e521d0148] | committer: Michael Niedermayer

avcodec/exr: Check line size for overflow

Fixes: signed integer overflow: 570425356 * 6 cannot be represented in type 'int
Fixes: 25929/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_EXR_fuzzer-5099197739827200

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=9b72cea4463dd2fabcd9ba1454a0855e521d0148
---

 libavcodec/exr.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libavcodec/exr.c b/libavcodec/exr.c
index c80e8eb5e0..162b3bb252 100644
--- a/libavcodec/exr.c
+++ b/libavcodec/exr.c
@@ -1040,6 +1040,9 @@ static int decode_block(AVCodecContext *avctx, void *tdata,
         td->ysize = FFMIN(s->tile_attr.ySize, s->ydelta - tile_y * s->tile_attr.ySize);
         td->xsize = FFMIN(s->tile_attr.xSize, s->xdelta - tile_x * s->tile_attr.xSize);
 
+        if (td->xsize * (uint64_t)s->current_channel_offset > INT_MAX)
+            return AVERROR_INVALIDDATA;
+
         td->channel_line_size = td->xsize * s->current_channel_offset;/* uncompress size of one line */
         uncompressed_size = td->channel_line_size * (uint64_t)td->ysize;/* uncompress size of the block */
     } else {
@@ -1059,6 +1062,9 @@ static int decode_block(AVCodecContext *avctx, void *tdata,
         td->ysize          = FFMIN(s->scan_lines_per_block, s->ymax - line + 1); /* s->ydelta - line ?? */
         td->xsize          = s->xdelta;
 
+        if (td->xsize * (uint64_t)s->current_channel_offset > INT_MAX)
+            return AVERROR_INVALIDDATA;
+
         td->channel_line_size = td->xsize * s->current_channel_offset;/* uncompress size of one line */
         uncompressed_size = td->channel_line_size * (uint64_t)td->ysize;/* uncompress size of the block */