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labeled-ipsec: Fix SA selection semantics

PATCH In review Venkat Yekkirala 1 participant 1 message Nov 8, 2006

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Networking Network drivers SELinux security module Security (LSM) +1 more subsystems
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Venkat Yekkirala

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PATCH 3/3 labeled-ipsec: Fix SA selection semantics

Fix the selection of an SA for an outgoing packet to be at the same context as the originating socket/flow. This eliminates the SELinux policy's ability to use/sendto SAs with contexts other than the socket's.

With this patch applied, the SELinux policy will require one or more of the following for a socket to be able to communicate with/without SAs:

1. To enable a socket to communicate without using labeled-IPSec SAs:

allow socket_t unlabeled_t:association { sendto recvfrom }

2. To enable a socket to communicate with labeled-IPSec SAs:

allow socket_t self:association { sendto }; allow socket_t peer_sa_t:association { recvfrom };

Signed-off-by Venkat Yekkirala <[email protected]>
---
 include/linux/security.h        |   19 -----
 net/xfrm/xfrm_policy.c          |    3 
 security/dummy.c                |    7 --
 security/selinux/hooks.c        |   26 +++++--
 security/selinux/include/xfrm.h |    7 --
 security/selinux/xfrm.c         |  101 ++++++++++++++----------------
 6 files changed, 70 insertions(+), 93 deletions(-)
include/linux/security.h +0 -19
@@ -886,11 +886,6 @@ struct request_sock;
  *	@xp contains the policy to check for a match.
  *	@fl contains the flow to check for a match.
  *	Return 1 if there is a match.
- * @xfrm_flow_state_match:
- *	@fl contains the flow key to match.
- *	@xfrm points to the xfrm_state to match.
- *	@xp points to the xfrm_policy to match.
- *	Return 1 if there is a match.
  * @xfrm_decode_session:
  *	@skb points to skb to decode.
  *	@secid points to the flow key secid to set.

@@ -1388,8 +1383,6 @@ struct security_operations {
 	int (*xfrm_policy_lookup)(struct xfrm_policy *xp, u32 fl_secid, u8 dir);
 	int (*xfrm_state_pol_flow_match)(struct xfrm_state *x,
 			struct xfrm_policy *xp, struct flowi *fl);
-	int (*xfrm_flow_state_match)(struct flowi *fl, struct xfrm_state *xfrm,
-			struct xfrm_policy *xp);
 	int (*xfrm_decode_session)(struct sk_buff *skb, u32 *secid, int ckall);
 #endif	/* CONFIG_SECURITY_NETWORK_XFRM */
 

@@ -3186,12 +3179,6 @@ static inline int security_xfrm_state_po
 	return security_ops->xfrm_state_pol_flow_match(x, xp, fl);
 }
 
-static inline int security_xfrm_flow_state_match(struct flowi *fl,
-			struct xfrm_state *xfrm, struct xfrm_policy *xp)
-{
-	return security_ops->xfrm_flow_state_match(fl, xfrm, xp);
-}
-
 static inline int security_xfrm_decode_session(struct sk_buff *skb, u32 *secid)
 {
 	return security_ops->xfrm_decode_session(skb, secid, 1);

@@ -3255,12 +3242,6 @@ static inline int security_xfrm_state_po
 	return 1;
 }
 
-static inline int security_xfrm_flow_state_match(struct flowi *fl,
-			struct xfrm_state *xfrm, struct xfrm_policy *xp)
-{
-	return 1;
-}
-
 static inline int security_xfrm_decode_session(struct sk_buff *skb, u32 *secid)
 {
 	return 0;
net/xfrm/xfrm_policy.c +2 -1
@@ -1894,7 +1894,8 @@ int xfrm_bundle_ok(struct xfrm_policy *p
 
 		if (fl && !xfrm_selector_match(&dst->xfrm->sel, fl, family))
 			return 0;
-		if (fl && !security_xfrm_flow_state_match(fl, dst->xfrm, pol))
+		if (fl && pol &&
+		    !security_xfrm_state_pol_flow_match(dst->xfrm, pol, fl))
 			return 0;
 		if (dst->xfrm->km.state != XFRM_STATE_VALID)
 			return 0;
security/dummy.c +0 -7
@@ -886,12 +886,6 @@ static int dummy_xfrm_state_pol_flow_mat
 	return 1;
 }
 
-static int dummy_xfrm_flow_state_match(struct flowi *fl, struct xfrm_state *xfrm,
-				struct xfrm_policy *xp)
-{
-	return 1;
-}
-
 static int dummy_xfrm_decode_session(struct sk_buff *skb, u32 *fl, int ckall)
 {
 	return 0;

@@ -1126,7 +1120,6 @@ void security_fixup_ops (struct security
 	set_to_dummy_if_null(ops, xfrm_state_delete_security);
 	set_to_dummy_if_null(ops, xfrm_policy_lookup);
 	set_to_dummy_if_null(ops, xfrm_state_pol_flow_match);
-	set_to_dummy_if_null(ops, xfrm_flow_state_match);
 	set_to_dummy_if_null(ops, xfrm_decode_session);
 #endif	/* CONFIG_SECURITY_NETWORK_XFRM */
 #ifdef CONFIG_KEYS
security/selinux/include/xfrm.h +2 -5
@@ -19,9 +19,6 @@ int selinux_xfrm_state_delete(struct xfr
 int selinux_xfrm_policy_lookup(struct xfrm_policy *xp, u32 fl_secid, u8 dir);
 int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x,
 			struct xfrm_policy *xp, struct flowi *fl);
-int selinux_xfrm_flow_state_match(struct flowi *fl, struct xfrm_state *xfrm,
-			struct xfrm_policy *xp);
-
 
 /*
  * Extract the security blob from the sock (it's actually on the socket)

@@ -38,7 +35,7 @@ static inline struct inode_security_stru
 int selinux_xfrm_sock_rcv_skb(u32 sid, struct sk_buff *skb,
 			struct avc_audit_data *ad);
 int selinux_xfrm_postroute_last(u32 isec_sid, struct sk_buff *skb,
-			struct avc_audit_data *ad);
+			struct avc_audit_data *ad, u8 proto);
 u32 selinux_socket_getpeer_dgram(struct sk_buff *skb);
 int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall);
 #else

@@ -49,7 +46,7 @@ static inline int selinux_xfrm_sock_rcv_
 }
 
 static inline int selinux_xfrm_postroute_last(u32 isec_sid, struct sk_buff *skb,
-			struct avc_audit_data *ad)
+			struct avc_audit_data *ad, u8 proto)
 {
 	return 0;
 }
security/selinux/hooks.c +17 -9
@@ -2888,7 +2888,8 @@ static void selinux_task_to_inode(struct
 }
 
 /* Returns error only if unable to parse addresses */
-static int selinux_parse_skb_ipv4(struct sk_buff *skb, struct avc_audit_data *ad)
+static int selinux_parse_skb_ipv4(struct sk_buff *skb,
+			struct avc_audit_data *ad, u8 *proto)
 {
 	int offset, ihlen, ret = -EINVAL;
 	struct iphdr _iph, *ih;

@@ -2906,6 +2907,9 @@ static int selinux_parse_skb_ipv4(struct
 	ad->u.net.v4info.daddr = ih->daddr;
 	ret = 0;
 
+	if (proto)
+		*proto = ih->protocol;
+
 	switch (ih->protocol) {
         case IPPROTO_TCP: {
         	struct tcphdr _tcph, *th;

@@ -2949,7 +2953,8 @@ out:
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 
 /* Returns error only if unable to parse addresses */
-static int selinux_parse_skb_ipv6(struct sk_buff *skb, struct avc_audit_data *ad)
+static int selinux_parse_skb_ipv6(struct sk_buff *skb,
+			struct avc_audit_data *ad, u8 *proto)
 {
 	u8 nexthdr;
 	int ret = -EINVAL, offset;

@@ -2970,6 +2975,9 @@ static int selinux_parse_skb_ipv6(struct
 	if (offset < 0)
 		goto out;
 
+	if (proto)
+		*proto = nexthdr;
+
 	switch (nexthdr) {
 	case IPPROTO_TCP: {
         	struct tcphdr _tcph, *th;

@@ -3006,13 +3014,13 @@ out:
 #endif /* IPV6 */
 
 static int selinux_parse_skb(struct sk_buff *skb, struct avc_audit_data *ad,
-			     char **addrp, int *len, int src)
+			     char **addrp, int *len, int src, u8 *proto)
 {
 	int ret = 0;
 
 	switch (ad->u.net.family) {
 	case PF_INET:
-		ret = selinux_parse_skb_ipv4(skb, ad);
+		ret = selinux_parse_skb_ipv4(skb, ad, proto);
 		if (ret || !addrp)
 			break;
 		*len = 4;

@@ -3022,7 +3030,7 @@ static int selinux_parse_skb(struct sk_b
 
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 	case PF_INET6:
-		ret = selinux_parse_skb_ipv6(skb, ad);
+		ret = selinux_parse_skb_ipv6(skb, ad, proto);
 		if (ret || !addrp)
 			break;
 		*len = 16;

@@ -3493,7 +3501,7 @@ static int selinux_socket_sock_rcv_skb(s
 	ad.u.net.netif = skb->dev ? skb->dev->name : "[unknown]";
 	ad.u.net.family = family;
 
-	err = selinux_parse_skb(skb, &ad, &addrp, &len, 1);
+	err = selinux_parse_skb(skb, &ad, &addrp, &len, 1, NULL);
 	if (err)
 		goto out;
 

@@ -3819,6 +3827,7 @@ static unsigned int selinux_ip_postroute
 	struct avc_audit_data ad;
 	struct net_device *dev = (struct net_device *)out;
 	struct sk_security_struct *sksec;
+	u8 proto;
 
 	sk = skb->sk;
 	if (!sk)

@@ -3830,7 +3839,7 @@ static unsigned int selinux_ip_postroute
 	ad.u.net.netif = dev->name;
 	ad.u.net.family = family;
 
-	err = selinux_parse_skb(skb, &ad, &addrp, &len, 0);
+	err = selinux_parse_skb(skb, &ad, &addrp, &len, 0, &proto);
 	if (err)
 		goto out;
 

@@ -3844,7 +3853,7 @@ static unsigned int selinux_ip_postroute
 	if (err)
 		goto out;
 
-	err = selinux_xfrm_postroute_last(sksec->sid, skb, &ad);
+	err = selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto);
 out:
 	return err ? NF_DROP : NF_ACCEPT;
 }

@@ -4763,7 +4772,6 @@ static struct security_operations selinu
 	.xfrm_state_delete_security =	selinux_xfrm_state_delete,
 	.xfrm_policy_lookup = 		selinux_xfrm_policy_lookup,
 	.xfrm_state_pol_flow_match =	selinux_xfrm_state_pol_flow_match,
-	.xfrm_flow_state_match =	selinux_xfrm_flow_state_match,
 	.xfrm_decode_session =		selinux_xfrm_decode_session,
 #endif
security/selinux/xfrm.c +49 -52

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