[FFmpeg-cvslog] jpegls: check the scan offset

[Luca Barbato]

ffmpeg | branch: release/0.10 | Luca Barbato <lu_zero at gentoo.org> | Fri May 17 13:08:55 2013 +0200| [d26bc6c6b69f8f87e51430234bbf4b22962e2b3f] | committer: Reinhard Tartler

jpegls: check the scan offset

Prevent an out of array bound write.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable at libav.org
(cherry picked from commit abad374909e6416e941351094f4f1446a71f8d23)

Signed-off-by: Reinhard Tartler <siretart at tauware.de>

Conflicts:
	libavcodec/jpeglsdec.c

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d26bc6c6b69f8f87e51430234bbf4b22962e2b3f
---

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

diff --git a/libavcodec/jpeglsdec.c b/libavcodec/jpeglsdec.c
index 63bf5cf..d234d73 100644
--- a/libavcodec/jpeglsdec.c
+++ b/libavcodec/jpeglsdec.c
@@ -286,6 +286,10 @@ int ff_jpegls_decode_picture(MJpegDecodeContext *s, int near, int point_transfor
 //    av_log(s->avctx, AV_LOG_DEBUG, "JPEG-LS params: %ix%i NEAR=%i MV=%i T(%i,%i,%i) RESET=%i, LIMIT=%i, qbpp=%i, RANGE=%i\n",s->width,s->height,state->near,state->maxval,state->T1,state->T2,state->T3,state->reset,state->limit,state->qbpp, state->range);
 //    av_log(s->avctx, AV_LOG_DEBUG, "JPEG params: ILV=%i Pt=%i BPP=%i, scan = %i\n", ilv, point_transform, s->bits, s->cur_scan);
     if(ilv == 0) { /* separate planes */
+        if (s->cur_scan > s->nb_components) {
+            ret = AVERROR_INVALIDDATA;
+            goto end;
+        }
         off = s->cur_scan - 1;
         stride = (s->nb_components > 1) ? 3 : 1;
         width = s->width * stride;