[FFmpeg-cvslog] pcx: round up in bits->bytes conversion in a buffer size check

[Anton Khirnov]

ffmpeg | branch: master | Anton Khirnov <anton at khirnov.net> | Fri Nov 15 19:06:23 2013 +0100| [430d12196432ded13f011a3bf7690f03c9b2e5d6] | committer: Anton Khirnov

pcx: round up in bits->bytes conversion in a buffer size check

Fixes invalid reads.
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable at libav.org

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=430d12196432ded13f011a3bf7690f03c9b2e5d6
---

 libavcodec/pcx.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/pcx.c b/libavcodec/pcx.c
index 1a5357b..61c971e 100644
--- a/libavcodec/pcx.c
+++ b/libavcodec/pcx.c
@@ -109,7 +109,7 @@ static int pcx_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
     nplanes            = buf[65];
     bytes_per_scanline = nplanes * bytes_per_line;
 
-    if (bytes_per_scanline < w * bits_per_pixel * nplanes / 8 ||
+    if (bytes_per_scanline < (w * bits_per_pixel * nplanes + 7) / 8 ||
         (!compressed && bytes_per_scanline > buf_size / h)) {
         av_log(avctx, AV_LOG_ERROR, "PCX data is corrupted\n");
         return AVERROR_INVALIDDATA;