linux-kernel - Re: [PATCH] kexec: prevent double free on image allocation failure

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87vc9l5cz4.fsf@xmission.com>
Date:	Thu, 21 Feb 2013 17:55:27 -0800
From:	ebiederm@...ssion.com (Eric W. Biederman)
To:	Sasha Levin <sasha.levin@...cle.com>
Cc:	kexec@...ts.infradead.org, linux-kernel@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH] kexec: prevent double free on image allocation failure

Sasha Levin <sasha.levin@...cle.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@...ssion.com>
> Signed-off-by: Sasha Levin <sasha.levin@...cle.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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/