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Commit b5745c59 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 

Pull SELinux fixes from James Morris.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  selinux: process labeled IPsec TCP SYN-ACK packets properly in selinux_ip_postroute()
  selinux: look for IPsec labels on both inbound and outbound packets
  selinux: handle TCP SYN-ACK packets correctly in selinux_ip_postroute()
  selinux: handle TCP SYN-ACK packets correctly in selinux_ip_output()
  selinux: fix possible memory leak
parents 29b1deb2 d93aca60

security/selinux/hooks.c

+112 −25
Original line number Diff line number Diff line
@@ -53,6 +53,7 @@ 
#include <net/ip.h>		/* for local_port_range[] */

#include <net/sock.h>

#include <net/tcp.h>		/* struct or_callable used in sock_rcv_skb */

#include <net/inet_connection_sock.h>

#include <net/net_namespace.h>

#include <net/netlabel.h>

#include <linux/uaccess.h>
@@ -3824,7 +3825,7 @@ static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid) 
	u32 nlbl_sid;

	u32 nlbl_type;



	err = selinux_skb_xfrm_sid(skb, &xfrm_sid);

	err = selinux_xfrm_skb_sid(skb, &xfrm_sid);

	if (unlikely(err))

		return -EACCES;

	err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
@@ -3842,6 +3843,30 @@ static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid) 
	return 0;

}



/**

 * selinux_conn_sid - Determine the child socket label for a connection

 * @sk_sid: the parent socket's SID

 * @skb_sid: the packet's SID

 * @conn_sid: the resulting connection SID

 *

 * If @skb_sid is valid then the user:role:type information from @sk_sid is

 * combined with the MLS information from @skb_sid in order to create

 * @conn_sid.  If @skb_sid is not valid then then @conn_sid is simply a copy

 * of @sk_sid.  Returns zero on success, negative values on failure.

 *

 */

static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid)

{

	int err = 0;



	if (skb_sid != SECSID_NULL)

		err = security_sid_mls_copy(sk_sid, skb_sid, conn_sid);

	else

		*conn_sid = sk_sid;



	return err;

}



/* socket security operations */



static int socket_sockcreate_sid(const struct task_security_struct *tsec,
@@ -4448,7 +4473,7 @@ static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, 
	struct sk_security_struct *sksec = sk->sk_security;

	int err;

	u16 family = sk->sk_family;

	u32 newsid;

	u32 connsid;

	u32 peersid;



	/* handle mapped IPv4 packets arriving via IPv6 sockets */
@@ -4458,16 +4483,11 @@ static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, 
	err = selinux_skb_peerlbl_sid(skb, family, &peersid);

	if (err)

		return err;

	if (peersid == SECSID_NULL) {

		req->secid = sksec->sid;

		req->peer_secid = SECSID_NULL;

	} else {

		err = security_sid_mls_copy(sksec->sid, peersid, &newsid);

	err = selinux_conn_sid(sksec->sid, peersid, &connsid);

	if (err)

		return err;

		req->secid = newsid;

	req->secid = connsid;

	req->peer_secid = peersid;

	}



	return selinux_netlbl_inet_conn_request(req, family);

}
@@ -4727,6 +4747,7 @@ static unsigned int selinux_ipv6_forward(const struct nf_hook_ops *ops, 
static unsigned int selinux_ip_output(struct sk_buff *skb,

				      u16 family)

{

	struct sock *sk;

	u32 sid;



	if (!netlbl_enabled())
@@ -4735,8 +4756,27 @@ static unsigned int selinux_ip_output(struct sk_buff *skb, 
	/* we do this in the LOCAL_OUT path and not the POST_ROUTING path

	 * because we want to make sure we apply the necessary labeling

	 * before IPsec is applied so we can leverage AH protection */

	if (skb->sk) {

		struct sk_security_struct *sksec = skb->sk->sk_security;

	sk = skb->sk;

	if (sk) {

		struct sk_security_struct *sksec;



		if (sk->sk_state == TCP_LISTEN)

			/* if the socket is the listening state then this

			 * packet is a SYN-ACK packet which means it needs to

			 * be labeled based on the connection/request_sock and

			 * not the parent socket.  unfortunately, we can't

			 * lookup the request_sock yet as it isn't queued on

			 * the parent socket until after the SYN-ACK is sent.

			 * the "solution" is to simply pass the packet as-is

			 * as any IP option based labeling should be copied

			 * from the initial connection request (in the IP

			 * layer).  it is far from ideal, but until we get a

			 * security label in the packet itself this is the

			 * best we can do. */

			return NF_ACCEPT;



		/* standard practice, label using the parent socket */

		sksec = sk->sk_security;

		sid = sksec->sid;

	} else

		sid = SECINITSID_KERNEL;
@@ -4806,27 +4846,36 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, 
	 * as fast and as clean as possible. */

	if (!selinux_policycap_netpeer)

		return selinux_ip_postroute_compat(skb, ifindex, family);



	secmark_active = selinux_secmark_enabled();

	peerlbl_active = selinux_peerlbl_enabled();

	if (!secmark_active && !peerlbl_active)

		return NF_ACCEPT;



	sk = skb->sk;



#ifdef CONFIG_XFRM

	/* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec

	 * packet transformation so allow the packet to pass without any checks

	 * since we'll have another chance to perform access control checks

	 * when the packet is on it's final way out.

	 * NOTE: there appear to be some IPv6 multicast cases where skb->dst

	 *       is NULL, in this case go ahead and apply access control. */

	if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL)

	 *       is NULL, in this case go ahead and apply access control.

	 * NOTE: if this is a local socket (skb->sk != NULL) that is in the

	 *       TCP listening state we cannot wait until the XFRM processing

	 *       is done as we will miss out on the SA label if we do;

	 *       unfortunately, this means more work, but it is only once per

	 *       connection. */

	if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL &&

	    !(sk != NULL && sk->sk_state == TCP_LISTEN))

		return NF_ACCEPT;

#endif

	secmark_active = selinux_secmark_enabled();

	peerlbl_active = selinux_peerlbl_enabled();

	if (!secmark_active && !peerlbl_active)

		return NF_ACCEPT;



	/* if the packet is being forwarded then get the peer label from the

	 * packet itself; otherwise check to see if it is from a local

	 * application or the kernel, if from an application get the peer label

	 * from the sending socket, otherwise use the kernel's sid */

	sk = skb->sk;

	if (sk == NULL) {

		/* Without an associated socket the packet is either coming

		 * from the kernel or it is being forwarded; check the packet

		 * to determine which and if the packet is being forwarded

		 * query the packet directly to determine the security label. */

		if (skb->skb_iif) {

			secmark_perm = PACKET__FORWARD_OUT;

			if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
@@ -4835,7 +4884,45 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, 
			secmark_perm = PACKET__SEND;

			peer_sid = SECINITSID_KERNEL;

		}

	} else if (sk->sk_state == TCP_LISTEN) {

		/* Locally generated packet but the associated socket is in the

		 * listening state which means this is a SYN-ACK packet.  In

		 * this particular case the correct security label is assigned

		 * to the connection/request_sock but unfortunately we can't

		 * query the request_sock as it isn't queued on the parent

		 * socket until after the SYN-ACK packet is sent; the only

		 * viable choice is to regenerate the label like we do in

		 * selinux_inet_conn_request().  See also selinux_ip_output()

		 * for similar problems. */

		u32 skb_sid;

		struct sk_security_struct *sksec = sk->sk_security;

		if (selinux_skb_peerlbl_sid(skb, family, &skb_sid))

			return NF_DROP;

		/* At this point, if the returned skb peerlbl is SECSID_NULL

		 * and the packet has been through at least one XFRM

		 * transformation then we must be dealing with the "final"

		 * form of labeled IPsec packet; since we've already applied

		 * all of our access controls on this packet we can safely

		 * pass the packet. */

		if (skb_sid == SECSID_NULL) {

			switch (family) {

			case PF_INET:

				if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)

					return NF_ACCEPT;

				break;

			case PF_INET6:

				if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)

					return NF_ACCEPT;

			default:

				return NF_DROP_ERR(-ECONNREFUSED);

			}

		}

		if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid))

			return NF_DROP;

		secmark_perm = PACKET__SEND;

	} else {

		/* Locally generated packet, fetch the security label from the

		 * associated socket. */

		struct sk_security_struct *sksec = sk->sk_security;

		peer_sid = sksec->sid;

		secmark_perm = PACKET__SEND;

security/selinux/include/xfrm.h

+5 −3
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ int selinux_xfrm_sock_rcv_skb(u32 sk_sid, struct sk_buff *skb, 
int selinux_xfrm_postroute_last(u32 sk_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)

{
@@ -79,11 +80,12 @@ static inline int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, 
static inline void selinux_xfrm_notify_policyload(void)

{

}

#endif



static inline int selinux_skb_xfrm_sid(struct sk_buff *skb, u32 *sid)

static inline int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid)

{

	return selinux_xfrm_decode_session(skb, sid, 0);

	*sid = SECSID_NULL;

	return 0;

}

#endif



#endif /* _SELINUX_XFRM_H_ */

security/selinux/xfrm.c

+48 −14
Original line number Diff line number Diff line
@@ -209,19 +209,26 @@ int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x, 
			    NULL) ? 0 : 1);

}



/*

 * 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 u32 selinux_xfrm_skb_sid_egress(struct sk_buff *skb)

{

	u32 sid_session = SECSID_NULL;

	struct sec_path *sp;

	struct dst_entry *dst = skb_dst(skb);

	struct xfrm_state *x;



	if (skb == NULL)

		goto out;

	if (dst == NULL)

		return SECSID_NULL;

	x = dst->xfrm;

	if (x == NULL || !selinux_authorizable_xfrm(x))

		return SECSID_NULL;



	return x->security->ctx_sid;

}



static int selinux_xfrm_skb_sid_ingress(struct sk_buff *skb,

					u32 *sid, int ckall)

{

	u32 sid_session = SECSID_NULL;

	struct sec_path *sp = skb->sp;



	sp = skb->sp;

	if (sp) {

		int i;
@@ -247,6 +254,30 @@ out: 
	return 0;

}



/*

 * 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;

}



/*

 * LSM hook implementation that allocs and transfers uctx spec to xfrm_policy.

 */
@@ -327,19 +358,22 @@ int selinux_xfrm_state_alloc_acquire(struct xfrm_state *x, 
		return rc;



	ctx = kmalloc(sizeof(*ctx) + str_len, GFP_ATOMIC);

	if (!ctx)

		return -ENOMEM;

	if (!ctx) {

		rc = -ENOMEM;

		goto out;

	}



	ctx->ctx_doi = XFRM_SC_DOI_LSM;

	ctx->ctx_alg = XFRM_SC_ALG_SELINUX;

	ctx->ctx_sid = secid;

	ctx->ctx_len = str_len;

	memcpy(ctx->ctx_str, ctx_str, str_len);

	kfree(ctx_str);



	x->security = ctx;

	atomic_inc(&selinux_xfrm_refcount);

	return 0;

out:

	kfree(ctx_str);

	return rc;

}



/*