[FFmpeg-cvslog] avcodec/jpeg2000dec: Check image offset

[Michael Niedermayer]

ffmpeg | branch: release/4.2 | Michael Niedermayer <michael at niedermayer.cc> | Wed Oct  4 23:32:17 2023 +0200| [6cec2a4a99f24fb3b491bf38f391a0a16dfa3b94] | committer: Michael Niedermayer

avcodec/jpeg2000dec: Check image offset

Fixes: left shift of negative value -538967841
Fixes: 62447/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_JPEG2000_fuzzer-6427134337613824

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Reviewed-by: Tomas Härdin <git at haerdin.se>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit 88453250dbe952e85899d04867914ef95785530e)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=6cec2a4a99f24fb3b491bf38f391a0a16dfa3b94
---

 libavcodec/jpeg2000dec.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index 77dcdb6b44..42a0dceeb0 100644
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -312,6 +312,11 @@ static int get_siz(Jpeg2000DecoderContext *s)
         return AVERROR_INVALIDDATA;
     }
 
+    if (s->image_offset_x >= s->width || s->image_offset_y >= s->height) {
+        av_log(s->avctx, AV_LOG_ERROR, "image offsets outside image");
+        return AVERROR_INVALIDDATA;
+    }
+
     if (s->reduction_factor && (s->image_offset_x || s->image_offset_y) ){
         av_log(s->avctx, AV_LOG_ERROR, "reduction factor with image offsets is not fully implemented");
         return AVERROR_PATCHWELCOME;