Re: [FFmpeg-devel] [PATCH] Fix potential integer overflow in mov_read_keys

[Michael Niedermayer]

On Wed, Sep 07, 2016 at 02:38:48PM -0700, Sergey Volk wrote:
> 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  wrote:
> 
> > Actual allocation size is computed as (count + 1)*sizeof(meta_keys), so
> > we need to check that (count + 1) won't cause overflow.
> >
> >

>  mov.c |2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 5f372bd81ec31f48d8a4b78f82a4ab9c82a9bb43  
> 0001-Fix-potential-integer-overflow-in-mov_read_keys.patch
> From 87a7a2e202ebb63362715054773a89ce1fc71743 Mon Sep 17 00:00:00 2001
> From: Sergey Volk 
> 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(-)

applied

thx

[...]

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Re: [FFmpeg-devel] [PATCH] Fix potential integer overflow in mov_read_keys

[Sergey Volk]

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  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 
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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[FFmpeg-devel] [PATCH] Fix potential integer overflow in mov_read_keys

[Sergey Volk]

Actual allocation size is computed as (count + 1)*sizeof(meta_keys), so
we need to check that (count + 1) won't cause overflow.
From cfc0f5a099284c95476d5c020dca05fb743ff5ae Mon Sep 17 00:00:00 2001
From: Sergey Volk 
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..ea7d051 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 + 1 > UINT_MAX / sizeof(*c->meta_keys)) {
 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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