[FFmpeg-cvslog] avcodec/exr: Check tile positions

[Michael Niedermayer]

ffmpeg | branch: release/3.1 | Michael Niedermayer <michael at niedermayer.cc> | Wed Aug 17 21:22:29 2016 +0200| [79f52a0dbd484aad111e4bf4a4f7047c7ceb6137] | committer: Michael Niedermayer

avcodec/exr: Check tile positions

This also disabled the case of mixed x/ymin with tiles, the code
handles these cases inconsistent for the 2 coordinate axis and is
unlikely working correctly.

Fixes crash
Fixes: poc1.exr, poc2.exr

Found-by: Yaoguang Chen of Aliapy unLimit Security Team
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 01aee8148d4fa439cce678a11f5110656c98de1f)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=79f52a0dbd484aad111e4bf4a4f7047c7ceb6137
---

 libavcodec/exr.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/libavcodec/exr.c b/libavcodec/exr.c
index cabe329..de46028 100644
--- a/libavcodec/exr.c
+++ b/libavcodec/exr.c
@@ -1027,8 +1027,9 @@ static int decode_block(AVCodecContext *avctx, void *tdata,
     uint64_t line_offset, uncompressed_size;
     uint16_t *ptr_x;
     uint8_t *ptr;
-    uint32_t data_size, line, col = 0;
-    uint32_t tileX, tileY, tileLevelX, tileLevelY;
+    uint32_t data_size;
+    uint64_t line, col = 0;
+    uint64_t tileX, tileY, tileLevelX, tileLevelY;
     const uint8_t *src;
     int axmax = (avctx->width - (s->xmax + 1)) * 2 * s->desc->nb_components; /* nb pixel to add at the right of the datawindow */
     int bxmin = s->xmin * 2 * s->desc->nb_components; /* nb pixel to add at the left of the datawindow */
@@ -1059,9 +1060,18 @@ static int decode_block(AVCodecContext *avctx, void *tdata,
             return AVERROR_PATCHWELCOME;
         }
 
+        if (s->xmin || s->ymin) {
+            avpriv_report_missing_feature(s->avctx, "Tiles with xmin/ymin");
+            return AVERROR_PATCHWELCOME;
+        }
+
         line = s->tile_attr.ySize * tileY;
         col = s->tile_attr.xSize * tileX;
 
+        if (line < s->ymin || line > s->ymax ||
+            col  < s->xmin || col  > s->xmax)
+            return AVERROR_INVALIDDATA;
+
         td->ysize = FFMIN(s->tile_attr.ySize, s->ydelta - tileY * s->tile_attr.ySize);
         td->xsize = FFMIN(s->tile_attr.xSize, s->xdelta - tileX * s->tile_attr.xSize);