[FFmpeg-cvslog] lagarith: reallocate rgb_planes when needed

[Anton Khirnov]

ffmpeg | branch: release/1.1 | Anton Khirnov <anton at khirnov.net> | Thu Nov 28 10:54:35 2013 +0100| [b4d72f901c96f526dc1090a77bf84cec4d2e000d] | committer: Reinhard Tartler

lagarith: reallocate rgb_planes when needed

Fixes invalid writes on pixel format changes.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC:libav-stable at libav.org
(cherry picked from commit 4c3e1956ee35fdcc5ffdb28782050164b4623c0b)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=b4d72f901c96f526dc1090a77bf84cec4d2e000d
---

 libavcodec/lagarith.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/libavcodec/lagarith.c b/libavcodec/lagarith.c
index 33dd8b0..5290d39 100644
--- a/libavcodec/lagarith.c
+++ b/libavcodec/lagarith.c
@@ -53,6 +53,7 @@ typedef struct LagarithContext {
     int zeros;                  /**< number of consecutive zero bytes encountered */
     int zeros_rem;              /**< number of zero bytes remaining to output */
     uint8_t *rgb_planes;
+    int      rgb_planes_allocated;
     int rgb_stride;
 } LagarithContext;
 
@@ -557,13 +558,12 @@ static int lag_decode_frame(AVCodecContext *avctx,
         offs[1] = offset_gu;
         offs[2] = offset_ry;
 
+        l->rgb_stride = FFALIGN(avctx->width, 16);
+        av_fast_malloc(&l->rgb_planes, &l->rgb_planes_allocated,
+                       l->rgb_stride * avctx->height * planes + 1);
         if (!l->rgb_planes) {
-            l->rgb_stride = FFALIGN(avctx->width, 16);
-            l->rgb_planes = av_malloc(l->rgb_stride * avctx->height * planes + 1);
-            if (!l->rgb_planes) {
-                av_log(avctx, AV_LOG_ERROR, "cannot allocate temporary buffer\n");
-                return AVERROR(ENOMEM);
-            }
+            av_log(avctx, AV_LOG_ERROR, "cannot allocate temporary buffer\n");
+            return AVERROR(ENOMEM);
         }
         for (i = 0; i < planes; i++)
             srcs[i] = l->rgb_planes + (i + 1) * l->rgb_stride * avctx->height - l->rgb_stride;