[FFmpeg-cvslog] lagarith: check count before writing zeros.

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Sat Apr 14 18:28:31 2012 +0200| [83c7803f55b3231faeb93c1a634399a70fae9480] | committer: Michael Niedermayer

lagarith: check count before writing zeros.

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=83c7803f55b3231faeb93c1a634399a70fae9480
---

 libavcodec/lagarith.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/libavcodec/lagarith.c b/libavcodec/lagarith.c
index 22d427e..7f47b75 100644
--- a/libavcodec/lagarith.c
+++ b/libavcodec/lagarith.c
@@ -326,6 +326,10 @@ static int lag_decode_zero_run_line(LagarithContext *l, uint8_t *dst,
 output_zeros:
     if (l->zeros_rem) {
         count = FFMIN(l->zeros_rem, width - i);
+        if(end - dst < count) {
+            av_log(l->avctx, AV_LOG_ERROR, "too many zeros remaining\n");
+            return AVERROR_INVALIDDATA;
+        }
         memset(dst, 0, count);
         l->zeros_rem -= count;
         dst += count;