[3.5.y.z extended stable] Patch "selinux: look for IPsec labels on both inbound and outbound packets" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    selinux: look for IPsec labels on both inbound and outbound packets

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From c69ea094531f0602780ee3740be9674818a9fe49 Mon Sep 17 00:00:00 2001
From: Paul Moore <pmoore at redhat.com>
Date: Thu, 19 Dec 2013 18:27:19 -0500
Subject: selinux: look for IPsec labels on both inbound and outbound packets

commit 817eff718dca4e54d5721211ddde0914428fbb7c upstream.

Previously selinux_skb_peerlbl_sid() would only check for labeled
IPsec security labels on inbound packets, this patch enables it to
check both inbound and outbound traffic for labeled IPsec security
labels.

Reported-by: Janak Desai <Janak.Desai at gtri.gatech.edu>
[ Paul: backported to 3.4 kernel ]
Signed-off-by: Paul Moore <pmoore at redhat.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 security/selinux/hooks.c        |  2 +-
 security/selinux/include/xfrm.h |  9 +++----
 security/selinux/xfrm.c         | 53 ++++++++++++++++++++++++++++++++---------
 3 files changed, 48 insertions(+), 16 deletions(-)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 7b40d22..a9ee3d1 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3735,7 +3735,7 @@ static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
 	u32 nlbl_sid;
 	u32 nlbl_type;

-	selinux_skb_xfrm_sid(skb, &xfrm_sid);
+	selinux_xfrm_skb_sid(skb, &xfrm_sid);
 	selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);

 	err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
diff --git a/security/selinux/include/xfrm.h b/security/selinux/include/xfrm.h
index c220f31..d1c980c 100644
--- a/security/selinux/include/xfrm.h
+++ b/security/selinux/include/xfrm.h
@@ -47,6 +47,7 @@ int selinux_xfrm_sock_rcv_skb(u32 sid, struct sk_buff *skb,
 int selinux_xfrm_postroute_last(u32 isec_sid, struct sk_buff *skb,
 			struct common_audit_data *ad, u8 proto);
 int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall);
+int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid);

 static inline void selinux_xfrm_notify_policyload(void)
 {
@@ -79,12 +80,12 @@ static inline int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int
 static inline void selinux_xfrm_notify_policyload(void)
 {
 }
-#endif

-static inline void selinux_skb_xfrm_sid(struct sk_buff *skb, u32 *sid)
+static inline int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid)
 {
-	int err = selinux_xfrm_decode_session(skb, sid, 0);
-	BUG_ON(err);
+	*sid = SECSID_NULL;
+	return 0;
 }
+#endif

 #endif /* _SELINUX_XFRM_H_ */
diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
index 8ab2951..1552b91 100644
--- a/security/selinux/xfrm.c
+++ b/security/selinux/xfrm.c
@@ -152,21 +152,13 @@ int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x, struct xfrm_policy *
 	return rc;
 }

-/*
- * LSM hook implementation that checks and/or returns the xfrm sid for the
- * incoming packet.
- */
-
-int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall)
+static int selinux_xfrm_skb_sid_ingress(struct sk_buff *skb,
+					u32 *sid, int ckall)
 {
-	struct sec_path *sp;
+	struct sec_path *sp = skb->sp;

 	*sid = SECSID_NULL;

-	if (skb == NULL)
-		return 0;
-
-	sp = skb->sp;
 	if (sp) {
 		int i, sid_set = 0;

@@ -190,6 +182,45 @@ int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall)
 	return 0;
 }

+static u32 selinux_xfrm_skb_sid_egress(struct sk_buff *skb)
+{
+	struct dst_entry *dst = skb_dst(skb);
+	struct xfrm_state *x;
+
+	if (dst == NULL)
+		return SECSID_NULL;
+	x = dst->xfrm;
+	if (x == NULL || !selinux_authorizable_xfrm(x))
+		return SECSID_NULL;
+
+	return x->security->ctx_sid;
+}
+
+/*
+ * LSM hook implementation that checks and/or returns the xfrm sid for the
+ * incoming packet.
+ */
+
+int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall)
+{
+	if (skb == NULL) {
+		*sid = SECSID_NULL;
+		return 0;
+	}
+	return selinux_xfrm_skb_sid_ingress(skb, sid, ckall);
+}
+
+int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid)
+{
+	int rc;
+
+	rc = selinux_xfrm_skb_sid_ingress(skb, sid, 0);
+	if (rc == 0 && *sid == SECSID_NULL)
+		*sid = selinux_xfrm_skb_sid_egress(skb);
+
+	return rc;
+}
+
 /*
  * Security blob allocation for xfrm_policy and xfrm_state
  * CTX does not have a meaningful value on input
--
1.8.3.2