From: Anton Khirnov <anton@khirnov.net>
Date: Fri, 15 Nov 2013 18:06:23 +0000 (+0100)
Subject: pcx: round up in bits->bytes conversion in a buffer size check
X-Git-Tag: n2.2-rc2~55^2~538
X-Git-Url: http://git.ffmpeg.org/gitweb/ffmpeg.git/commitdiff_plain/430d12196432ded13f011a3bf7690f03c9b2e5d6

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@libav.org
---

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;