Re: [PATCH v2] xfrm: policy: Fix possible user after free in __xfrm_policy_unlink

[Herbert Xu]

On Thu, Feb 28, 2019 at 02:38:01PM +0800, Yue Haibing wrote:
>
> diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
> index a131f9f..aaa45c9 100644
> --- a/net/xfrm/xfrm_user.c
> +++ b/net/xfrm/xfrm_user.c
> @@ -1424,7 +1424,8 @@ static int verify_newpolicy_info(struct xfrm_userpolicy_info *p)
>  	ret = verify_policy_dir(p->dir);
>  	if (ret)
>  		return ret;
> -	if (p->index && ((p->index & XFRM_POLICY_MAX) != p->dir))
> +	if (p->index && (((p->index & XFRM_POLICY_MAX) != p->dir) ||
> +			 (xfrm_policy_id2dir(p->index) >= XFRM_POLICY_MAX)))

Please just check 

	xfrm_policy_id2dir(p->index) != p->dir

Thanks,
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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