diff mbox series

[v2,08/25] LSM: Use lsmblob in security_secctx_to_secid

Message ID 20190618230551.7475-9-casey@schaufler-ca.com (mailing list archive)
State Superseded
Headers show
Series LSM: Module stacking for AppArmor | expand

Commit Message

Casey Schaufler June 18, 2019, 11:05 p.m. UTC
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.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/security.h          |  5 +++--
 kernel/cred.c                     |  4 +---
 net/netfilter/nft_meta.c          | 13 ++++++-------
 net/netfilter/xt_SECMARK.c        |  6 ++++--
 net/netlabel/netlabel_unlabeled.c | 14 ++++++++------
 security/security.c               | 15 ++++++++++++---
 6 files changed, 34 insertions(+), 23 deletions(-)
diff mbox series

Patch

diff --git a/include/linux/security.h b/include/linux/security.h
index 64f5cc2dd249..dcaaa63b79b3 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -443,7 +443,8 @@  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 *l);
 void security_release_secctx(char *secdata, u32 seclen);
 
 void security_inode_invalidate_secctx(struct inode *inode);
@@ -1226,7 +1227,7 @@  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 *l)
 {
 	return -EOPNOTSUPP;
 }
diff --git a/kernel/cred.c b/kernel/cred.c
index e71a16f177dc..fa4051365d70 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -725,14 +725,12 @@  EXPORT_SYMBOL(set_security_override);
 int set_security_override_from_ctx(struct cred *new, const char *secctx)
 {
 	struct lsmblob le;
-	u32 secid;
 	int ret;
 
-	ret = security_secctx_to_secid(secctx, strlen(secctx), &secid);
+	ret = security_secctx_to_secid(secctx, strlen(secctx), &le);
 	if (ret < 0)
 		return ret;
 
-	lsmblob_init(&le, secid);
 	return set_security_override(new, &le);
 }
 EXPORT_SYMBOL(set_security_override_from_ctx);
diff --git a/net/netfilter/nft_meta.c b/net/netfilter/nft_meta.c
index 987d2d6ce624..b6e41cb1c76e 100644
--- a/net/netfilter/nft_meta.c
+++ b/net/netfilter/nft_meta.c
@@ -576,21 +576,20 @@  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 le;
 	int err;
 
-	err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &tmp_secid);
+	err = security_secctx_to_secid(priv->ctx, strlen(priv->ctx), &le);
 	if (err)
 		return err;
 
-	if (!tmp_secid)
-		return -ENOENT;
-
-	err = security_secmark_relabel_packet(tmp_secid);
+	/* Using le[1] is scaffolding */
+	err = security_secmark_relabel_packet(le.secid[1]);
 	if (err)
 		return err;
 
-	priv->secid = tmp_secid;
+	/* Using le[1] is scaffolding */
+	priv->secid = le.secid[1];
 	return 0;
 }
 
diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
index f16202d26c20..040eb9515769 100644
--- a/net/netfilter/xt_SECMARK.c
+++ b/net/netfilter/xt_SECMARK.c
@@ -49,13 +49,13 @@  secmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
 
 static int checkentry_lsm(struct xt_secmark_target_info *info)
 {
+	struct lsmblob le;
 	int err;
 
 	info->secctx[SECMARK_SECCTX_MAX - 1] = '\0';
 	info->secid = 0;
 
-	err = security_secctx_to_secid(info->secctx, strlen(info->secctx),
-				       &info->secid);
+	err = security_secctx_to_secid(info->secctx, strlen(info->secctx), &le);
 	if (err) {
 		if (err == -EINVAL)
 			pr_info_ratelimited("invalid security context \'%s\'\n",
@@ -63,6 +63,8 @@  static int checkentry_lsm(struct xt_secmark_target_info *info)
 		return err;
 	}
 
+	/* scaffolding during the transition */
+	info->secid = le.secid[1];
 	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 c92894c3e40a..30873e671d05 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -895,7 +895,7 @@  static int netlbl_unlabel_staticadd(struct sk_buff *skb,
 	void *addr;
 	void *mask;
 	u32 addr_len;
-	u32 secid;
+	struct lsmblob le;
 	struct netlbl_audit audit_info;
 
 	/* Don't allow users to add both IPv4 and IPv6 addresses for a
@@ -919,12 +919,13 @@  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);
+				  &le);
 	if (ret_val != 0)
 		return ret_val;
 
+	/* scaffolding with the [1] */
 	return netlbl_unlhsh_add(&init_net,
-				 dev_name, addr, mask, addr_len, secid,
+				 dev_name, addr, mask, addr_len, le.secid[1],
 				 &audit_info);
 }
 
@@ -946,7 +947,7 @@  static int netlbl_unlabel_staticadddef(struct sk_buff *skb,
 	void *addr;
 	void *mask;
 	u32 addr_len;
-	u32 secid;
+	struct lsmblob le;
 	struct netlbl_audit audit_info;
 
 	/* Don't allow users to add both IPv4 and IPv6 addresses for a
@@ -968,12 +969,13 @@  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);
+				  &le);
 	if (ret_val != 0)
 		return ret_val;
 
+	/* scaffolding with the [1] */
 	return netlbl_unlhsh_add(&init_net,
-				 NULL, addr, mask, addr_len, secid,
+				 NULL, addr, mask, addr_len, le.secid[1],
 				 &audit_info);
 }
 
diff --git a/security/security.c b/security/security.c
index 5ed818699e15..44927bf13d32 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1994,10 +1994,19 @@  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 *l)
 {
-	*secid = 0;
-	return call_int_hook(secctx_to_secid, 0, secdata, seclen, secid);
+	struct security_hook_list *hp;
+	int rc;
+
+	lsmblob_init(l, 0);
+	hlist_for_each_entry(hp, &security_hook_heads.secctx_to_secid, list) {
+		rc = hp->hook.secctx_to_secid(secdata, seclen,
+					      &l->secid[hp->slot]);
+		if (rc != 0)
+			return rc;
+	}
+	return 0;
 }
 EXPORT_SYMBOL(security_secctx_to_secid);