I just realized that count+1 itself might overflow if count==UINT_MAX, so I
guess it's better to subtract 1 from the right-hand side. Attached updated
patch.
On Wed, Sep 7, 2016 at 2:21 PM, Sergey Volk <serv...@chromium.org> wrote:
> Actual allocation size is computed as (count + 1)*sizeof(meta_keys), so
> we need to check that (count + 1) won't cause overflow.
>
>
From 87a7a2e202ebb63362715054773a89ce1fc71743 Mon Sep 17 00:00:00 2001
From: Sergey Volk <serv...@google.com>
Date: Wed, 7 Sep 2016 14:05:35 -0700
Subject: [PATCH] Fix potential integer overflow in mov_read_keys
Actual allocation size is computed as (count + 1)*sizeof(meta_keys), so
we need to check that (count + 1) won't cause overflow.
---
libavformat/mov.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libavformat/mov.c b/libavformat/mov.c
index f499906..a7595c5 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -3278,7 +3278,7 @@ static int mov_read_keys(MOVContext *c, AVIOContext *pb, MOVAtom atom)
avio_skip(pb, 4);
count = avio_rb32(pb);
- if (count > UINT_MAX / sizeof(*c->meta_keys)) {
+ if (count > UINT_MAX / sizeof(*c->meta_keys) - 1) {
av_log(c->fc, AV_LOG_ERROR,
"The 'keys' atom with the invalid key count: %d\n", count);
return AVERROR_INVALIDDATA;
--
2.8.0.rc3.226.g39d4020
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