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From: ebiederm@xmission.com (Eric W. Biederman)
To: Sasha Levin <sasha.levin@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
	kexec@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] kexec: prevent double free on image allocation failure
Date: Thu, 21 Feb 2013 17:55:27 -0800	[thread overview]
Message-ID: <87vc9l5cz4.fsf@xmission.com> (raw)
In-Reply-To: <1361496375-30994-1-git-send-email-sasha.levin@oracle.com> (Sasha Levin's message of "Thu, 21 Feb 2013 20:26:15 -0500")

Sasha Levin <sasha.levin@oracle.com> writes:

> If kimage_normal_alloc() fails to initialize an allocated kimage, it will free
> the image but would still set 'rimage', as a result kexec_load will try
> to free it again.
>
> This would explode as part of the freeing process is accessing internal
> members which point to uninitialized memory.

Agreed.

I don't think that failure path has ever actually been exercised.

The code is wrong, and it is worth fixing.

Andrew I do you think you could queue this up?  I don't have a handy tree.

Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
> ---
>  kernel/kexec.c | 2 --
>  1 file changed, 2 deletions(-)
>
> diff --git a/kernel/kexec.c b/kernel/kexec.c
> index 2348bd6..855bfbb 100644
> --- a/kernel/kexec.c
> +++ b/kernel/kexec.c
> @@ -242,8 +242,6 @@ static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
>  	if (result)
>  		goto out;
>  
> -	*rimage = image;
> -
>  	/*
>  	 * Find a location for the control code buffer, and add it
>  	 * the vector of segments so that it's pages will also be

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WARNING: multiple messages have this Message-ID (diff)
From: ebiederm@xmission.com (Eric W. Biederman)
To: Sasha Levin <sasha.levin@oracle.com>
Cc: kexec@lists.infradead.org, linux-kernel@vger.kernel.org,
	Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] kexec: prevent double free on image allocation failure
Date: Thu, 21 Feb 2013 17:55:27 -0800	[thread overview]
Message-ID: <87vc9l5cz4.fsf@xmission.com> (raw)
In-Reply-To: <1361496375-30994-1-git-send-email-sasha.levin@oracle.com> (Sasha Levin's message of "Thu, 21 Feb 2013 20:26:15 -0500")

Sasha Levin <sasha.levin@oracle.com> writes:

> If kimage_normal_alloc() fails to initialize an allocated kimage, it will free
> the image but would still set 'rimage', as a result kexec_load will try
> to free it again.
>
> This would explode as part of the freeing process is accessing internal
> members which point to uninitialized memory.

Agreed.

I don't think that failure path has ever actually been exercised.

The code is wrong, and it is worth fixing.

Andrew I do you think you could queue this up?  I don't have a handy tree.

Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
> Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
> ---
>  kernel/kexec.c | 2 --
>  1 file changed, 2 deletions(-)
>
> diff --git a/kernel/kexec.c b/kernel/kexec.c
> index 2348bd6..855bfbb 100644
> --- a/kernel/kexec.c
> +++ b/kernel/kexec.c
> @@ -242,8 +242,6 @@ static int kimage_normal_alloc(struct kimage **rimage, unsigned long entry,
>  	if (result)
>  		goto out;
>  
> -	*rimage = image;
> -
>  	/*
>  	 * Find a location for the control code buffer, and add it
>  	 * the vector of segments so that it's pages will also be

  reply	other threads:[~2013-02-22  1:55 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-22  1:26 [PATCH] kexec: prevent double free on image allocation failure Sasha Levin
2013-02-22  1:26 ` Sasha Levin
2013-02-22  1:55 ` Eric W. Biederman [this message]
2013-02-22  1:55   ` Eric W. Biederman
2013-02-22  2:33   ` Sasha Levin
2013-02-22  2:33     ` Sasha Levin
2013-02-22  2:46   ` Zhang Yanfei
2013-02-22  2:46     ` Zhang Yanfei
2013-02-22  3:41     ` Sasha Levin
2013-02-22  3:41       ` Sasha Levin
2013-02-22  3:58       ` Zhang Yanfei
2013-02-22  3:58         ` Zhang Yanfei

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