[FFmpeg-cvslog] avcodec/jpeg2000dec: move bpno check to a earlier place

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Sun Jun 16 15:27:39 2013 +0200| [3b8617429014301b26b587a5e537910746d3377a] | committer: Michael Niedermayer

avcodec/jpeg2000dec: move bpno check to a earlier place

This prevents additional integer overflows

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=3b8617429014301b26b587a5e537910746d3377a
---

 libavcodec/jpeg2000dec.c |   14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/libavcodec/jpeg2000dec.c b/libavcodec/jpeg2000dec.c
index f821292..9da6610 100644
--- a/libavcodec/jpeg2000dec.c
+++ b/libavcodec/jpeg2000dec.c
@@ -633,10 +633,16 @@ static int jpeg2000_decode_packet(Jpeg2000DecoderContext *s,
             else if (incl < 0)
                 return incl;
 
-            if (!cblk->npasses)
-                cblk->nonzerobits = expn[bandno] + numgbits - 1 -
+            if (!cblk->npasses) {
+                int v = expn[bandno] + numgbits - 1 -
                                     tag_tree_decode(s, prec->zerobits + cblkno,
                                                     100);
+                if (v < 0) {
+                    av_log(s->avctx, AV_LOG_ERROR, "nonzerobits %d invalid\n", v);
+                    return AVERROR_INVALIDDATA;
+                }
+                cblk->nonzerobits = v;
+            }
             if ((newpasses = getnpasses(s)) < 0)
                 return newpasses;
             if ((llen = getlblockinc(s)) < 0)
@@ -913,10 +919,6 @@ static int decode_cblk(Jpeg2000DecoderContext *s, Jpeg2000CodingStyle *codsty,
     ff_mqc_initdec(&t1->mqc, cblk->data);
 
     while (passno--) {
-        if (bpno < 0) {
-            av_log(s->avctx, AV_LOG_ERROR, "bpno invalid\n");
-            return AVERROR(EINVAL);
-        }
         switch(pass_t) {
         case 0:
             decode_sigpass(t1, width, height, bpno + 1, bandpos,