lcldec: ensure that the offset for av_memcpy_backptr is valid.

Originally committed as revision 19067 to svn://svn.ffmpeg.org/ffmpeg/trunk
16 years ago · a7bfbe4e13
parent 4ec42240ca
commit a7bfbe4e13
1 changed files with 1 additions and 0 deletions
--- a/libavcodec/lcldec.c
+++ b/libavcodec/lcldec.c
@ -93,6 +93,7 @@ static unsigned int mszh_decomp(const unsigned char * srcptr, int srclen, unsign
            unsigned ofs = bytestream_get_le16(&srcptr);
            unsigned cnt = (ofs >> 11) + 1;
            ofs &= 0x7ff;
+            ofs = FFMIN(ofs, destptr - destptr_bak);
            cnt *= 4;
            cnt = FFMIN(cnt, destptr_end - destptr);
            av_memcpy_backptr(destptr, ofs, cnt);