ffmpeg | branch: release/2.5 | Michael Niedermayer <michae...@gmx.at> | Tue Dec 16 18:57:54 2014 +0100| [991ef3a67ec66b3f4e11752eff48b6ae925a1ba7] | committer: Michael Niedermayer
avcodec/xface: correct the XFACE_MAX_* values Fixes out of array access Fixes: asan_stack-oob_32c12e5_2536_cov_2442316831_lena.xface Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Michael Niedermayer <michae...@gmx.at> (cherry picked from commit 93a5a16f136d095d23610f57bdad10ba88120fba) Signed-off-by: Michael Niedermayer <michae...@gmx.at> > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=991ef3a67ec66b3f4e11752eff48b6ae925a1ba7 --- libavcodec/xface.h | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/libavcodec/xface.h b/libavcodec/xface.h index 63df5d3..0236d71 100644 --- a/libavcodec/xface.h +++ b/libavcodec/xface.h @@ -41,17 +41,17 @@ /* * Image is encoded as a big integer, using characters from '~' to * '!', for a total of 94 symbols. In order to express - * 48x48*2=8*XFACE_MAX_WORDS=4608 - * bits, we need a total of 704 digits, as given by: - * ceil(lg_94(2^4608)) = 704 + * 48x48 pixels with the worst case encoding 666 symbols should + * be sufficient. */ -#define XFACE_MAX_DIGITS 704 +#define XFACE_MAX_DIGITS 666 #define XFACE_BITSPERWORD 8 #define XFACE_WORDCARRY (1 << XFACE_BITSPERWORD) #define XFACE_WORDMASK (XFACE_WORDCARRY - 1) -#define XFACE_MAX_WORDS ((XFACE_PIXELS * 2 + XFACE_BITSPERWORD - 1) / XFACE_BITSPERWORD) +// This must be larger or equal to log256(94^XFACE_MAX_DIGITS) +#define XFACE_MAX_WORDS 546 /* Portable, very large unsigned integer arithmetic is needed. * Implementation uses arrays of WORDs. */ _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog
