1 files changed, 79 insertions, 56 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index ada0d0bf3463..8426a2aa8dce 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2097,6 +2097,41 @@ static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
 
 /* binprm security operations */
 
+static int check_nnp_nosuid(const struct linux_binprm *bprm,
+			    const struct task_security_struct *old_tsec,
+			    const struct task_security_struct *new_tsec)
+{
+	int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS);
+	int nosuid = (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID);
+	int rc;
+
+	if (!nnp && !nosuid)
+		return 0; /* neither NNP nor nosuid */
+
+	if (new_tsec->sid == old_tsec->sid)
+		return 0; /* No change in credentials */
+
+	/*
+	 * The only transitions we permit under NNP or nosuid
+	 * are transitions to bounded SIDs, i.e. SIDs that are
+	 * guaranteed to only be allowed a subset of the permissions
+	 * of the current SID.
+	 */
+	rc = security_bounded_transition(old_tsec->sid, new_tsec->sid);
+	if (rc) {
+		/*
+		 * On failure, preserve the errno values for NNP vs nosuid.
+		 * NNP:  Operation not permitted for caller.
+		 * nosuid:  Permission denied to file.
+		 */
+		if (nnp)
+			return -EPERM;
+		else
+			return -EACCES;
+	}
+	return 0;
+}
+
 static int selinux_bprm_set_creds(struct linux_binprm *bprm)
 {
 	const struct task_security_struct *old_tsec;
@@ -2133,14 +2168,10 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm)
 		/* Reset exec SID on execve. */
 		new_tsec->exec_sid = 0;
 
-		/*
-		 * Minimize confusion: if no_new_privs or nosuid and a
-		 * transition is explicitly requested, then fail the exec.
-		 */
-		if (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)
-			return -EPERM;
-		if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
-			return -EACCES;
+		/* Fail on NNP or nosuid if not an allowed transition. */
+		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
+		if (rc)
+			return rc;
 	} else {
 		/* Check for a default transition on this program. */
 		rc = security_transition_sid(old_tsec->sid, isec->sid,
@@ -2148,15 +2179,19 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm)
 					     &new_tsec->sid);
 		if (rc)
 			return rc;
+
+		/*
+		 * Fallback to old SID on NNP or nosuid if not an allowed
+		 * transition.
+		 */
+		rc = check_nnp_nosuid(bprm, old_tsec, new_tsec);
+		if (rc)
+			new_tsec->sid = old_tsec->sid;
 	}
 
 	ad.type = LSM_AUDIT_DATA_PATH;
 	ad.u.path = bprm->file->f_path;
 
-	if ((bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) ||
-	    (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS))
-		new_tsec->sid = old_tsec->sid;
-
 	if (new_tsec->sid == old_tsec->sid) {
 		rc = avc_has_perm(old_tsec->sid, isec->sid,
 				  SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
@@ -4270,15 +4305,15 @@ static int selinux_socket_unix_may_send(struct socket *sock,
 			    &ad);
 }
 
-static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
-				    u32 peer_sid,
+static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
+				    char *addrp, u16 family, u32 peer_sid,
 				    struct common_audit_data *ad)
 {
 	int err;
 	u32 if_sid;
 	u32 node_sid;
 
-	err = sel_netif_sid(ifindex, &if_sid);
+	err = sel_netif_sid(ns, ifindex, &if_sid);
 	if (err)
 		return err;
 	err = avc_has_perm(peer_sid, if_sid,
@@ -4371,8 +4406,8 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 		err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
 		if (err)
 			return err;
-		err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
-					       peer_sid, &ad);
+		err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
+					       addrp, family, peer_sid, &ad);
 		if (err) {
 			selinux_netlbl_err(skb, err, 0);
 			return err;
@@ -4690,10 +4725,9 @@ static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
 	err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
 	if (err) {
 		if (err == -EINVAL) {
-			audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
-				  "SELinux:  unrecognized netlink message"
-				  " type=%hu for sclass=%hu\n",
-				  nlh->nlmsg_type, sksec->sclass);
+			WARN_ONCE(1, "selinux_nlmsg_perm: unrecognized netlink message:"
+				  " protocol=%hu nlmsg_type=%hu sclass=%hu\n",
+				  sk->sk_protocol, nlh->nlmsg_type, sksec->sclass);
 			if (!selinux_enforcing || security_get_allow_unknown())
 				err = 0;
 		}
@@ -4711,7 +4745,8 @@ out:
 
 #ifdef CONFIG_NETFILTER
 
-static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
+static unsigned int selinux_ip_forward(struct sk_buff *skb,
+				       const struct net_device *indev,
 				       u16 family)
 {
 	int err;
@@ -4737,14 +4772,14 @@ static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
 
 	ad.type = LSM_AUDIT_DATA_NET;
 	ad.u.net = &net;
-	ad.u.net->netif = ifindex;
+	ad.u.net->netif = indev->ifindex;
 	ad.u.net->family = family;
 	if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
 		return NF_DROP;
 
 	if (peerlbl_active) {
-		err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
-					       peer_sid, &ad);
+		err = selinux_inet_sys_rcv_skb(dev_net(indev), indev->ifindex,
+					       addrp, family, peer_sid, &ad);
 		if (err) {
 			selinux_netlbl_err(skb, err, 1);
 			return NF_DROP;
@@ -4773,7 +4808,7 @@ static unsigned int selinux_ipv4_forward(const struct nf_hook_ops *ops,
 					 const struct net_device *out,
 					 int (*okfn)(struct sk_buff *))
 {
-	return selinux_ip_forward(skb, in->ifindex, PF_INET);
+	return selinux_ip_forward(skb, in, PF_INET);
 }
 
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
@@ -4783,7 +4818,7 @@ static unsigned int selinux_ipv6_forward(const struct nf_hook_ops *ops,
 					 const struct net_device *out,
 					 int (*okfn)(struct sk_buff *))
 {
-	return selinux_ip_forward(skb, in->ifindex, PF_INET6);
+	return selinux_ip_forward(skb, in, PF_INET6);
 }
 #endif	/* IPV6 */
 
@@ -4871,11 +4906,13 @@ static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
 	return NF_ACCEPT;
 }
 
-static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
+static unsigned int selinux_ip_postroute(struct sk_buff *skb,
+					 const struct net_device *outdev,
 					 u16 family)
 {
 	u32 secmark_perm;
 	u32 peer_sid;
+	int ifindex = outdev->ifindex;
 	struct sock *sk;
 	struct common_audit_data ad;
 	struct lsm_network_audit net = {0,};
@@ -4956,6 +4993,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
 			case PF_INET6:
 				if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
 					return NF_ACCEPT;
+				break;
 			default:
 				return NF_DROP_ERR(-ECONNREFUSED);
 			}
@@ -4987,7 +5025,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
 		u32 if_sid;
 		u32 node_sid;
 
-		if (sel_netif_sid(ifindex, &if_sid))
+		if (sel_netif_sid(dev_net(outdev), ifindex, &if_sid))
 			return NF_DROP;
 		if (avc_has_perm(peer_sid, if_sid,
 				 SECCLASS_NETIF, NETIF__EGRESS, &ad))
@@ -5009,7 +5047,7 @@ static unsigned int selinux_ipv4_postroute(const struct nf_hook_ops *ops,
 					   const struct net_device *out,
 					   int (*okfn)(struct sk_buff *))
 {
-	return selinux_ip_postroute(skb, out->ifindex, PF_INET);
+	return selinux_ip_postroute(skb, out, PF_INET);
 }
 
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
@@ -5019,7 +5057,7 @@ static unsigned int selinux_ipv6_postroute(const struct nf_hook_ops *ops,
 					   const struct net_device *out,
 					   int (*okfn)(struct sk_buff *))
 {
-	return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
+	return selinux_ip_postroute(skb, out, PF_INET6);
 }
 #endif	/* IPV6 */
 
@@ -6033,7 +6071,7 @@ security_initcall(selinux_init);
 
 #if defined(CONFIG_NETFILTER)
 
-static struct nf_hook_ops selinux_ipv4_ops[] = {
+static struct nf_hook_ops selinux_nf_ops[] = {
 	{
 		.hook =		selinux_ipv4_postroute,
 		.owner =	THIS_MODULE,
@@ -6054,12 +6092,8 @@ static struct nf_hook_ops selinux_ipv4_ops[] = {
 		.pf =		NFPROTO_IPV4,
 		.hooknum =	NF_INET_LOCAL_OUT,
 		.priority =	NF_IP_PRI_SELINUX_FIRST,
-	}
-};
-
+	},
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
-
-static struct nf_hook_ops selinux_ipv6_ops[] = {
 	{
 		.hook =		selinux_ipv6_postroute,
 		.owner =	THIS_MODULE,
@@ -6073,32 +6107,24 @@ static struct nf_hook_ops selinux_ipv6_ops[] = {
 		.pf =		NFPROTO_IPV6,
 		.hooknum =	NF_INET_FORWARD,
 		.priority =	NF_IP6_PRI_SELINUX_FIRST,
-	}
-};
-
+	},
 #endif	/* IPV6 */
+};
 
 static int __init selinux_nf_ip_init(void)
 {
-	int err = 0;
+	int err;
 
 	if (!selinux_enabled)
-		goto out;
+		return 0;
 
 	printk(KERN_DEBUG "SELinux:  Registering netfilter hooks\n");
 
-	err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
+	err = nf_register_hooks(selinux_nf_ops, ARRAY_SIZE(selinux_nf_ops));
 	if (err)
-		panic("SELinux: nf_register_hooks for IPv4: error %d\n", err);
+		panic("SELinux: nf_register_hooks: error %d\n", err);
 
-#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
-	err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
-	if (err)
-		panic("SELinux: nf_register_hooks for IPv6: error %d\n", err);
-#endif	/* IPV6 */
-
-out:
-	return err;
+	return 0;
 }
 
 __initcall(selinux_nf_ip_init);
@@ -6108,10 +6134,7 @@ static void selinux_nf_ip_exit(void)
 {
 	printk(KERN_DEBUG "SELinux:  Unregistering netfilter hooks\n");
 
-	nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
-#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
-	nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
-#endif	/* IPV6 */
+	nf_unregister_hooks(selinux_nf_ops, ARRAY_SIZE(selinux_nf_ops));
 }
 #endif