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From: John Johansen <john.johansen@canonical.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: keescook@chromium.org, penguin-kernel@i-love.sakura.ne.jp,
	paul@paul-moore.com, sds@tycho.nsa.gov
Subject: Re: [PATCH v11 06/25] LSM: Use lsmblob in security_secctx_to_secid
Date: Thu, 21 Nov 2019 10:42:20 -0800
Message-ID: <5639aa97-2a22-c284-951a-fed9704ec16a@canonical.com> (raw)
In-Reply-To: <20191113181925.2437-7-casey@schaufler-ca.com>

On 11/13/19 10:19 AM, Casey Schaufler wrote:
> Change security_secctx_to_secid() to fill in a lsmblob instead
> of a u32 secid. Multiple LSMs may be able to interpret the
> string, and this allows for setting whichever secid is
> appropriate. In some cases there is scaffolding where other
> interfaces have yet to be converted.
> 
> Reviewed-by: Kees Cook <keescook@chromium.org>
> Reviewed-by: John Johansen <john.johansen@canonical.com>
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>


Acked-by: John Johansen <john.johansen@canonical.com>


> ---
>  include/linux/security.h          |  5 +++--
>  kernel/cred.c                     |  4 +---
>  net/netfilter/nft_meta.c          | 13 ++++++-------
>  net/netfilter/xt_SECMARK.c        |  5 ++++-
>  net/netlabel/netlabel_unlabeled.c | 14 ++++++++------
>  security/security.c               | 18 +++++++++++++++---
>  6 files changed, 37 insertions(+), 22 deletions(-)
> 
> diff --git a/include/linux/security.h b/include/linux/security.h
> index d57f400a307e..b69877a13efa 100644
> --- a/include/linux/security.h
> +++ b/include/linux/security.h
> @@ -494,7 +494,8 @@ int security_setprocattr(const char *lsm, const char *name, void *value,
>  int security_netlink_send(struct sock *sk, struct sk_buff *skb);
>  int security_ismaclabel(const char *name);
>  int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
> -int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid);
> +int security_secctx_to_secid(const char *secdata, u32 seclen,
> +			     struct lsmblob *blob);
>  void security_release_secctx(char *secdata, u32 seclen);
>  void security_inode_invalidate_secctx(struct inode *inode);
>  int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
> @@ -1300,7 +1301,7 @@ static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *secle
>  
>  static inline int security_secctx_to_secid(const char *secdata,
>  					   u32 seclen,
> -					   u32 *secid)
> +					   struct lsmblob *blob)
>  {
>  	return -EOPNOTSUPP;
>  }
> diff --git a/kernel/cred.c b/kernel/cred.c
> index 846ac4b23c16..7fef90f3f10b 100644
> --- a/kernel/cred.c
> +++ b/kernel/cred.c
> @@ -756,14 +756,12 @@ EXPORT_SYMBOL(set_security_override);
>  int set_security_override_from_ctx(struct cred *new, const char *secctx)
>  {
>  	struct lsmblob blob;
> -	u32 secid;
>  	int ret;
>  
> -	ret = security_secctx_to_secid(secctx, strlen(secctx), &secid);
> +	ret = security_secctx_to_secid(secctx, strlen(secctx), &blob);
>  	if (ret < 0)
>  		return ret;
>  
> -	lsmblob_init(&blob, secid);
>  	return set_security_override(new, &blob);
>  }
>  EXPORT_SYMBOL(set_security_override_from_ctx);
> diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
> index 317e3a9e8c5b..7c49397c33fd 100644
> --- a/net/netfilter/nft_meta.c
> +++ b/net/netfilter/nft_meta.c
> @@ -617,21 +617,20 @@ static const struct nla_policy nft_secmark_policy[NFTA_SECMARK_MAX + 1] = {
>  
>  static int nft_secmark_compute_secid(struct nft_secmark *priv)
>  {
> -	u32 tmp_secid = 0;
> +	struct lsmblob blob;
>  	int err;
>  
> -	err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid);
> +	err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &blob);
>  	if (err)
>  		return err;
>  
> -	if (!tmp_secid)
> -		return -ENOENT;
> -
> -	err = security_secmark_relabel_packet(tmp_secid);
> +	/* Using le[0] is scaffolding */
> +	err = security_secmark_relabel_packet(blob.secid[0]);
>  	if (err)
>  		return err;
>  
> -	priv->secid = tmp_secid;
> +	/* Using le[0] is scaffolding */
> +	priv->secid = blob.secid[0];
>  	return 0;
>  }
>  
> diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
> index 2317721f3ecb..2d68416b4552 100644
> --- a/net/netfilter/xt_SECMARK.c
> +++ b/net/netfilter/xt_SECMARK.c
> @@ -45,13 +45,14 @@ secmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
>  
>  static int checkentry_lsm(struct xt_secmark_target_info *info)
>  {
> +	struct lsmblob blob;
>  	int err;
>  
>  	info->secctx[SECMARK_SECCTX_MAX - 1] = '\0';
>  	info->secid = 0;
>  
>  	err = security_secctx_to_secid(info->secctx, strlen(info->secctx),
> -				       &info->secid);
> +				       &blob);
>  	if (err) {
>  		if (err == -EINVAL)
>  			pr_info_ratelimited("invalid security context \'%s\'\n",
> @@ -59,6 +60,8 @@ static int checkentry_lsm(struct xt_secmark_target_info *info)
>  		return err;
>  	}
>  
> +	/* scaffolding during the transition */
> +	info->secid = blob.secid[0];
>  	if (!info->secid) {
>  		pr_info_ratelimited("unable to map security context \'%s\'\n",
>  				    info->secctx);
> diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
> index d2e4ab8d1cb1..7a5a87f15736 100644
> --- a/net/netlabel/netlabel_unlabeled.c
> +++ b/net/netlabel/netlabel_unlabeled.c
> @@ -881,7 +881,7 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
>  	void *addr;
>  	void *mask;
>  	u32 addr_len;
> -	u32 secid;
> +	struct lsmblob blob;
>  	struct netlbl_audit audit_info;
>  
>  	/* Don't allow users to add both IPv4 and IPv6 addresses for a
> @@ -905,12 +905,13 @@ static int netlbl_unlabel_staticadd(struct sk_buff *skb,
>  	ret_val = security_secctx_to_secid(
>  		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
>  				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
> -				  &secid);
> +				  &blob);
>  	if (ret_val != 0)
>  		return ret_val;
>  
> +	/* scaffolding with the [0] */
>  	return netlbl_unlhsh_add(&init_net,
> -				 dev_name, addr, mask, addr_len, secid,
> +				 dev_name, addr, mask, addr_len, blob.secid[0],
>  				 &audit_info);
>  }
>  
> @@ -932,7 +933,7 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
>  	void *addr;
>  	void *mask;
>  	u32 addr_len;
> -	u32 secid;
> +	struct lsmblob blob;
>  	struct netlbl_audit audit_info;
>  
>  	/* Don't allow users to add both IPv4 and IPv6 addresses for a
> @@ -954,12 +955,13 @@ static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
>  	ret_val = security_secctx_to_secid(
>  		                  nla_data(info->attrs[NLBL_UNLABEL_A_SECCTX]),
>  				  nla_len(info->attrs[NLBL_UNLABEL_A_SECCTX]),
> -				  &secid);
> +				  &blob);
>  	if (ret_val != 0)
>  		return ret_val;
>  
> +	/* scaffolding with the [0] */
>  	return netlbl_unlhsh_add(&init_net,
> -				 NULL, addr, mask, addr_len, secid,
> +				 NULL, addr, mask, addr_len, blob.secid[0],
>  				 &audit_info);
>  }
>  
> diff --git a/security/security.c b/security/security.c
> index 55837706e3ef..32bb5383de9b 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1970,10 +1970,22 @@ int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
>  }
>  EXPORT_SYMBOL(security_secid_to_secctx);
>  
> -int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
> +int security_secctx_to_secid(const char *secdata, u32 seclen,
> +			     struct lsmblob *blob)
>  {
> -	*secid = 0;
> -	return call_int_hook(secctx_to_secid, 0, secdata, seclen, secid);
> +	struct security_hook_list *hp;
> +	int rc;
> +
> +	lsmblob_init(blob, 0);
> +	hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
> +		if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot))
> +			continue;
> +		rc = hp->hook.secctx_to_secid(secdata, seclen,
> +					      &blob->secid[hp->lsmid->slot]);
> +		if (rc != 0)
> +			return rc;
> +	}
> +	return 0;
>  }
>  EXPORT_SYMBOL(security_secctx_to_secid);
>  
> 


  reply index

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20191113181925.2437-1-casey.ref@schaufler-ca.com>
2019-11-13 18:19 ` [PATCH v11 00/25] LSM: Module stacking for AppArmor Casey Schaufler
2019-11-13 18:19   ` [PATCH v11 01/25] LSM: Infrastructure management of the sock security Casey Schaufler
2019-11-21 18:39     ` John Johansen
2019-11-13 18:19   ` [PATCH v11 02/25] LSM: Create and manage the lsmblob data structure Casey Schaufler
2019-11-21 18:40     ` John Johansen
2019-11-13 18:19   ` [PATCH v11 03/25] LSM: Use lsmblob in security_audit_rule_match Casey Schaufler
2019-11-21 18:40     ` John Johansen
2019-11-13 18:19   ` [PATCH v11 04/25] LSM: Use lsmblob in security_kernel_act_as Casey Schaufler
2019-11-21 18:41     ` John Johansen
2019-11-13 18:19   ` [PATCH v11 05/25] net: Prepare UDS for security module stacking Casey Schaufler
2019-11-21 18:41     ` John Johansen
2019-11-13 18:19   ` [PATCH v11 06/25] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
2019-11-21 18:42     ` John Johansen [this message]
2019-11-13 18:19   ` [PATCH v11 07/25] LSM: Use lsmblob in security_secid_to_secctx Casey Schaufler
2019-11-21 18:42     ` John Johansen
2019-11-13 18:19   ` [PATCH v11 08/25] LSM: Use lsmblob in security_ipc_getsecid Casey Schaufler
2019-11-21 18:43     ` John Johansen
2019-11-13 18:19   ` [PATCH v11 09/25] LSM: Use lsmblob in security_task_getsecid Casey Schaufler
2019-11-21 18:43     ` John Johansen
2019-11-13 18:19   ` [PATCH v11 10/25] LSM: Use lsmblob in security_inode_getsecid Casey Schaufler
2019-11-21 18:44     ` John Johansen
2019-11-13 18:19   ` [PATCH v11 11/25] LSM: Use lsmblob in security_cred_getsecid Casey Schaufler
2019-11-21 18:44     ` John Johansen
2019-11-13 18:19   ` [PATCH v11 12/25] IMA: Change internal interfaces to use lsmblobs Casey Schaufler
2019-11-21 18:45     ` John Johansen
2019-11-13 18:19   ` [PATCH v11 13/25] LSM: Specify which LSM to display Casey Schaufler
2019-11-13 18:19   ` [PATCH v11 14/25] LSM: Ensure the correct LSM context releaser Casey Schaufler
2019-11-21 19:00     ` John Johansen
2019-11-13 18:19   ` [PATCH v11 15/25] LSM: Use lsmcontext in security_secid_to_secctx Casey Schaufler
2019-11-13 18:19   ` [PATCH v11 16/25] LSM: Use lsmcontext in security_dentry_init_security Casey Schaufler
2019-11-21 19:00     ` John Johansen
2019-11-13 18:19   ` [PATCH v11 17/25] LSM: Use lsmcontext in security_inode_getsecctx Casey Schaufler
2019-11-13 17:56 [PATCH v11 00/25] LSM: Module stacking for AppArmor Casey Schaufler
2019-11-13 17:57 ` [PATCH v11 06/25] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler
  -- strict thread matches above, loose matches on Subject: below --
2019-11-13 16:50 [PATCH v11 00/25] LSM: Module stacking for AppArmor Casey Schaufler
2019-11-13 16:50 ` [PATCH v11 06/25] LSM: Use lsmblob in security_secctx_to_secid Casey Schaufler

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