Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Message-ID: <3862fed24a1265611f71327ddb444e52557bdc7c.camel@linux.ibm.com>
Subject: Re: [PATCH v24 04/25] IMA: avoid label collisions with stacked LSMs
From:   Mimi Zohar <zohar@linux.ibm.com>
To:     Casey Schaufler <casey@schaufler-ca.com>,
        casey.schaufler@intel.com, jmorris@namei.org,
        linux-security-module@vger.kernel.org, selinux@vger.kernel.org
Cc:     linux-audit@redhat.com, keescook@chromium.org,
        john.johansen@canonical.com, penguin-kernel@i-love.sakura.ne.jp,
        paul@paul-moore.com, sds@tycho.nsa.gov,
        linux-kernel@vger.kernel.org
Date:   Mon, 22 Feb 2021 19:27:07 -0500
In-Reply-To: <77ebed19-2912-d8f2-cb4d-3f782c8e7f18@schaufler-ca.com>
References: <20210126164108.1958-1-casey@schaufler-ca.com>
         <20210126164108.1958-5-casey@schaufler-ca.com>
         <693f81d9d2f50a920cafbbc8d1d634598b99081a.camel@linux.ibm.com>
         <77ebed19-2912-d8f2-cb4d-3f782c8e7f18@schaufler-ca.com>
Content-Type: text/plain; charset="ISO-8859-15"
Mime-Version: 1.0
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Mon, 2021-02-22 at 15:45 -0800, Casey Schaufler wrote:
> On 2/14/2021 10:21 AM, Mimi Zohar wrote:
> 
> Would these changes match your suggestion?
> 
>  security/integrity/ima/ima_policy.c | 24 ++++++++++++------------
>  1 file changed, 12 insertions(+), 12 deletions(-)
> 
> diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c
> index 9ac673472781..e80956548243 100644
> --- a/security/integrity/ima/ima_policy.c
> +++ b/security/integrity/ima/ima_policy.c
> @@ -78,11 +78,11 @@ struct ima_rule_entry {
>  	bool (*uid_op)(kuid_t, kuid_t);    /* Handlers for operators       */
>  	bool (*fowner_op)(kuid_t, kuid_t); /* uid_eq(), uid_gt(), uid_lt() */
>  	int pcr;
> +	int which_lsm; /* which of the rules to use */
>  	struct {
>  		void *rules[LSMBLOB_ENTRIES]; /* LSM file metadata specific */

If each IMA policy rule may only contain a single LSM specific
LSM_OBJ_{USER | ROLE | TYPE} and LSM_SUBJ_{USER | ROLE | TYPE}, then
there is no need for rules[LSMBLOB_ENTRIES].  Leave it as "*rule".

Otherwise it looks good.

Mimi

>  		char *args_p;	/* audit value */
>  		int type;	/* audit type */
> -		int which_lsm; /* which of the rules to use */
>  	} lsm[MAX_LSM_RULES];
>  	char *fsname;
>  	struct ima_rule_opt_list *keyrings; /* Measure keys added to these keyrings */