[FFmpeg-devel] [PATCH 3/3] avcodec/exr: Check line size for overflow

[Michael Niedermayer]

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

diff --git a/libavcodec/exr.c b/libavcodec/exr.c
index 8621a8cfe4..3bf2e29018 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 */
 
-- 
2.17.1