From 237958f8e82ce608c0f9ebb072653354e1d9ecca Mon Sep 17 00:00:00 2001
From: Michael Niedermayer <michaelni@gmx.at>
Date: Sun, 14 Dec 2014 17:26:11 +0100
Subject: [PATCH] avformat/aviobuf: Check that avio_seek() target is non
 negative

Fixes out of array access

Suggested-by: Andrew Scherkus <scherkus@google.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit ed86dbd05d61363dc1c0d33f3267e2177c985fdd)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
---
 libavformat/aviobuf.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
index 7a73a1791f..dc7dbb233b 100644
--- a/libavformat/aviobuf.c
+++ b/libavformat/aviobuf.c
@@ -216,6 +216,9 @@ int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
             return offset1;
         offset += offset1;
     }
+    if (offset < 0)
+        return AVERROR(EINVAL);
+
     offset1 = offset - pos;
     if (!s->must_flush && (!s->direct || !s->seek) &&
         offset1 >= 0 && offset1 <= (s->buf_end - s->buffer)) {