[PATCH] kexec: prevent double free on image allocation failure

[Eric W. Biederman]

Sasha Levin <sasha.levin at 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 at xmission.com>
> Signed-off-by: Sasha Levin <sasha.levin at 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