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From: Casey Schaufler <casey@schaufler-ca.com>
To: casey.schaufler@intel.com, jmorris@namei.org,
	linux-security-module@vger.kernel.org, selinux@vger.kernel.org
Cc: casey@schaufler-ca.com
Subject: [PATCH 67/90] Smack: Detect if secmarks can be safely used
Date: Thu, 18 Apr 2019 17:45:54 -0700
Message-ID: <20190419004617.64627-68-casey@schaufler-ca.com> (raw)
In-Reply-To: <20190419004617.64627-1-casey@schaufler-ca.com>

Utilize the security_secmark_refcount_in() hooks to determine
if Smack can safely assume that IP secmarks are not being used
by another LSM. Only use secmarks if they can be determined to
belong to Smack.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 security/smack/smack.h           | 15 +++++++++++++++
 security/smack/smack_lsm.c       | 16 +++++-----------
 security/smack/smack_netfilter.c | 25 +++++++++++++++++++++++--
 3 files changed, 43 insertions(+), 13 deletions(-)

diff --git a/security/smack/smack.h b/security/smack/smack.h
index 7cc3a3382fee..66ad1c175002 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -544,4 +544,19 @@ static inline void smk_ad_setfield_u_net_sk(struct smk_audit_info *a,
 }
 #endif
 
+#ifdef CONFIG_SECURITY_SMACK_NETFILTER
+extern bool smack_use_secmark;
+void smack_secmark_refcount_inc(void);
+
+static inline bool smk_use_secmark(void)
+{
+	return smack_use_secmark;
+}
+#else
+static inline bool smk_use_secmark(void)
+{
+	return false;
+}
+#endif
+
 #endif  /* _SECURITY_SMACK_H */
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index aaca4ba53032..d76aa0fc37a4 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3828,7 +3828,7 @@ static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
  */
 static struct smack_known *smack_from_skb(struct sk_buff *skb)
 {
-	if (skb == NULL || skb->secmark == 0)
+	if (skb == NULL || skb->secmark == 0 || !smk_use_secmark())
 		return NULL;
 
 	return smack_from_secid(skb->secmark);
@@ -3862,7 +3862,6 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 
 	switch (family) {
 	case PF_INET:
-#ifdef CONFIG_SECURITY_SMACK_NETFILTER
 		/*
 		 * If there is a secmark use it rather than the CIPSO label.
 		 * If there is no secmark fall back to CIPSO.
@@ -3871,7 +3870,6 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 		skp = smack_from_skb(skb);
 		if (skp)
 			goto access_check;
-#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
 		/*
 		 * Translate what netlabel gave us.
 		 */
@@ -3885,9 +3883,8 @@ static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
 
 		netlbl_secattr_destroy(&secattr);
 
-#ifdef CONFIG_SECURITY_SMACK_NETFILTER
 access_check:
-#endif
+
 #ifdef CONFIG_AUDIT
 		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
 		ad.a.u.net->family = family;
@@ -4014,13 +4011,11 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
 		s = ssp->smk_out->smk_secid;
 		break;
 	case PF_INET:
-#ifdef CONFIG_SECURITY_SMACK_NETFILTER
 		skp = smack_from_skb(skb);
 		if (skp) {
 			s = skp->smk_secid;
 			break;
 		}
-#endif
 		/*
 		 * Translate what netlabel gave us.
 		 */
@@ -4110,7 +4105,6 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
 	}
 #endif /* CONFIG_IPV6 */
 
-#ifdef CONFIG_SECURITY_SMACK_NETFILTER
 	/*
 	 * If there is a secmark use it rather than the CIPSO label.
 	 * If there is no secmark fall back to CIPSO.
@@ -4119,7 +4113,6 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
 	skp = smack_from_skb(skb);
 	if (skp)
 		goto access_check;
-#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
 
 	netlbl_secattr_init(&secattr);
 	rc = netlbl_skbuff_getattr(skb, family, &secattr);
@@ -4129,9 +4122,7 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
 		skp = &smack_known_huh;
 	netlbl_secattr_destroy(&secattr);
 
-#ifdef CONFIG_SECURITY_SMACK_NETFILTER
 access_check:
-#endif
 
 #ifdef CONFIG_AUDIT
 	smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
@@ -4708,6 +4699,9 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(sk_alloc_security, smack_sk_alloc_security),
 #ifdef SMACK_IPV6_PORT_LABELING
 	LSM_HOOK_INIT(sk_free_security, smack_sk_free_security),
+#endif
+#ifdef CONFIG_SECURITY_SMACK_NETFILTER
+	LSM_HOOK_INIT(secmark_refcount_inc, smack_secmark_refcount_inc),
 #endif
 	LSM_HOOK_INIT(sock_graft, smack_sock_graft),
 	LSM_HOOK_INIT(inet_conn_request, smack_inet_conn_request),
diff --git a/security/smack/smack_netfilter.c b/security/smack/smack_netfilter.c
index 701a1cc1bdcc..ea45b173f8ca 100644
--- a/security/smack/smack_netfilter.c
+++ b/security/smack/smack_netfilter.c
@@ -21,6 +21,15 @@
 #include <net/net_namespace.h>
 #include "smack.h"
 
+bool smack_use_secmark;
+static bool smack_checked_secmark;
+
+void smack_secmark_refcount_inc(void)
+{
+        smack_use_secmark = true;
+	pr_info("Smack: Using network secmarks.\n");
+}
+
 #if IS_ENABLED(CONFIG_IPV6)
 
 static unsigned int smack_ipv6_output(void *priv,
@@ -31,7 +40,13 @@ static unsigned int smack_ipv6_output(void *priv,
 	struct socket_smack *ssp;
 	struct smack_known *skp;
 
-	if (sk && smack_sock(sk)) {
+	if (!smack_checked_secmark) {
+		security_secmark_refcount_inc();
+		security_secmark_refcount_dec();
+		smack_checked_secmark = true;
+	}
+
+	if (smack_use_secmark && sk && smack_sock(sk)) {
 		ssp = smack_sock(sk);
 		skp = ssp->smk_out;
 		skb->secmark = skp->smk_secid;
@@ -49,7 +64,13 @@ static unsigned int smack_ipv4_output(void *priv,
 	struct socket_smack *ssp;
 	struct smack_known *skp;
 
-	if (sk && smack_sock(sk)) {
+	if (!smack_checked_secmark) {
+		security_secmark_refcount_inc();
+		security_secmark_refcount_dec();
+		smack_checked_secmark = true;
+	}
+
+	if (smack_use_secmark && sk && smack_sock(sk)) {
 		ssp = smack_sock(sk);
 		skp = ssp->smk_out;
 		skb->secmark = skp->smk_secid;
-- 
2.19.1


  parent reply index

Thread overview: 89+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-19  0:44 [PATCH 00/90] LSM: Module stacking for all Casey Schaufler
2019-04-19  0:44 ` [PATCH 01/90] LSM: Infrastructure management of the superblock Casey Schaufler
2019-04-19  0:44 ` [PATCH 02/90] LSM: Infrastructure management of the sock security Casey Schaufler
2019-04-19  0:44 ` [PATCH 03/90] LSM: Infrastructure management of the key security blob Casey Schaufler
2019-04-19  0:44 ` [PATCH 04/90] LSM: Create an lsm_export data structure Casey Schaufler
2019-04-19  0:44 ` [PATCH 05/90] LSM: Use lsm_export in the inode_getsecid hooks Casey Schaufler
2019-04-19  0:44 ` [PATCH 06/90] LSM: Use lsm_export in the cred_getsecid hooks Casey Schaufler
2019-04-19  0:44 ` [PATCH 07/90] LSM: Use lsm_export in the ipc_getsecid and task_getsecid hooks Casey Schaufler
2019-04-19  0:44 ` [PATCH 08/90] LSM: Use lsm_export in the kernel_ask_as hooks Casey Schaufler
2019-04-19  0:44 ` [PATCH 09/90] LSM: Use lsm_export in the getpeersec_dgram hooks Casey Schaufler
2019-04-19  0:44 ` [PATCH 10/90] LSM: Use lsm_export in the audit_rule_match hooks Casey Schaufler
2019-04-19  0:44 ` [PATCH 11/90] LSM: Fix logical operation in lsm_export checks Casey Schaufler
2019-04-19  0:44 ` [PATCH 12/90] LSM: Use lsm_export in the secid_to_secctx hooks Casey Schaufler
2019-04-19  0:45 ` [PATCH 13/90] LSM: Use lsm_export in the secctx_to_secid hooks Casey Schaufler
2019-04-19  0:45 ` [PATCH 14/90] LSM: Use lsm_export in security_audit_rule_match Casey Schaufler
2019-04-19  0:45 ` [PATCH 15/90] LSM: Use lsm_export in security_kernel_act_as Casey Schaufler
2019-04-19  0:45 ` [PATCH 16/90] LSM: Use lsm_export in security_socket_getpeersec_dgram Casey Schaufler
2019-04-19  0:45 ` [PATCH 17/90] LSM: Use lsm_export in security_secctx_to_secid Casey Schaufler
2019-04-19  0:45 ` [PATCH 18/90] LSM: Use lsm_export in security_secid_to_secctx Casey Schaufler
2019-04-19  0:45 ` [PATCH 19/90] LSM: Use lsm_export in security_ipc_getsecid Casey Schaufler
2019-04-19  0:45 ` [PATCH 20/90] LSM: Use lsm_export in security_task_getsecid Casey Schaufler
2019-04-19  0:45 ` [PATCH 21/90] LSM: Use lsm_export in security_inode_getsecid Casey Schaufler
2019-04-19  0:45 ` [PATCH 22/90] LSM: Use lsm_export in security_cred_getsecid Casey Schaufler
2019-04-19  0:45 ` [PATCH 23/90] Audit: Change audit_sig_sid to audit_sig_lsm Casey Schaufler
2019-04-19  0:45 ` [PATCH 24/90] Audit: Convert target_sid to an lsm_export structure Casey Schaufler
2019-04-19  0:45 ` [PATCH 25/90] Audit: Convert osid " Casey Schaufler
2019-04-19  0:45 ` [PATCH 26/90] IMA: Clean out lsm_export scaffolding Casey Schaufler
2019-04-19  0:45 ` [PATCH 27/90] NET: Change the UNIXCB from a secid to an lsm_export Casey Schaufler
2019-04-19  0:45 ` [PATCH 28/90] NET: Remove scaffolding on secmarks Casey Schaufler
2019-04-19  0:45 ` [PATCH 29/90] NET: Remove scaffolding on new secmarks Casey Schaufler
2019-04-19  0:45 ` [PATCH 30/90] NET: Remove netfilter scaffolding for lsm_export Casey Schaufler
2019-04-19  0:45 ` [PATCH 31/90] Netlabel: Replace secids with lsm_export Casey Schaufler
2019-04-19  0:45 ` [PATCH 32/90] LSM: Remove lsm_export scaffolding functions Casey Schaufler
2019-04-19  0:45 ` [PATCH 33/90] IMA: FIXUP prototype using lsm_export Casey Schaufler
2019-04-19  0:45 ` [PATCH 34/90] Smack: Restore the release_secctx hook Casey Schaufler
2019-04-19  0:45 ` [PATCH 35/90] AppArmor: Remove unnecessary hook stub Casey Schaufler
2019-04-19  0:45 ` [PATCH 36/90] LSM: Limit calls to certain module hooks Casey Schaufler
2019-04-19  0:45 ` [PATCH 37/90] LSM: Create a data structure for a security context Casey Schaufler
2019-04-19  0:45 ` [PATCH 38/90] LSM: Use lsm_context in secid_to_secctx hooks Casey Schaufler
2019-04-19  0:45 ` [PATCH 39/90] LSM: Use lsm_context in secctx_to_secid hooks Casey Schaufler
2019-04-19  0:45 ` [PATCH 40/90] LSM: Use lsm_context in inode_getsecctx hooks Casey Schaufler
2019-04-19  0:45 ` [PATCH 41/90] LSM: Use lsm_context in inode_notifysecctx hooks Casey Schaufler
2019-04-19  0:45 ` [PATCH 42/90] LSM: Use lsm_context in dentry_init_security hooks Casey Schaufler
2019-04-19  0:45 ` [PATCH 43/90] LSM: Use lsm_context in security_dentry_init_security Casey Schaufler
2019-04-19  0:45 ` [PATCH 44/90] LSM: Use lsm_context in security_inode_notifysecctx Casey Schaufler
2019-04-19  0:45 ` [PATCH 45/90] LSM: Use lsm_context in security_inode_getsecctx Casey Schaufler
2019-04-19  0:45 ` [PATCH 46/90] LSM: Use lsm_context in security_secctx_to_secid Casey Schaufler
2019-04-19  0:45 ` [PATCH 47/90] LSM: Use lsm_context in release_secctx hooks Casey Schaufler
2019-04-19  0:45 ` [PATCH 48/90] LSM: Use lsm_context in security_release_secctx Casey Schaufler
2019-04-19  0:45 ` [PATCH 49/90] LSM: Use lsm_context in security_secid_to_secctx Casey Schaufler
2019-04-19  0:45 ` [PATCH 50/90] fs: remove lsm_context scaffolding Casey Schaufler
2019-04-19  0:45 ` [PATCH 51/90] LSM: Add the release function to the lsm_context Casey Schaufler
2019-04-19  0:45 ` [PATCH 52/90] LSM: Use lsm_context in inode_setsecctx hooks Casey Schaufler
2019-04-19  0:45 ` [PATCH 53/90] LSM: Use lsm_context in security_inode_setsecctx Casey Schaufler
2019-04-19  0:45 ` [PATCH 54/90] kernfs: remove lsm_context scaffolding Casey Schaufler
2019-04-19  0:45 ` [PATCH 55/90] LSM: Remove unused macro Casey Schaufler
2019-04-19  0:45 ` [PATCH 56/90] LSM: Special handling for secctx lsm hooks Casey Schaufler
2019-04-19  0:45 ` [PATCH 57/90] SELinux: Use blob offset in current_sid Casey Schaufler
2019-04-19  0:45 ` [PATCH 58/90] LSM: Specify which LSM to display Casey Schaufler
2019-04-19  0:45 ` [PATCH 59/90] AppArmor: Remove the exclusive flag Casey Schaufler
2019-04-19  0:45 ` [PATCH 60/90] LSM: Add secmark_relabel_packet to the set of one call hooks Casey Schaufler
2019-04-19  0:45 ` [PATCH 61/90] LSM: Make getting the secmark right cleaner Casey Schaufler
2019-04-19  0:45 ` [PATCH 62/90] netfilter: Fix memory leak introduced with lsm_context Casey Schaufler
2019-04-19  0:45 ` [PATCH 63/90] Smack: Consolidate secmark conversions Casey Schaufler
2019-04-19  0:45 ` [PATCH 64/90] netfilter: Remove unnecessary NULL check in lsm_context Casey Schaufler
2019-04-19  0:45 ` [PATCH 65/90] LSM: Add secmark refcounting to call_one list Casey Schaufler
2019-04-19  0:45 ` [PATCH 66/90] LSM: refactor security_setprocattr Casey Schaufler
2019-04-19  0:45 ` Casey Schaufler [this message]
2019-04-19  0:45 ` [PATCH 68/90] LSM: Support multiple LSMs using inode_init_security Casey Schaufler
2019-04-19  0:45 ` [PATCH 69/90] LSM: Use full security context in security_inode_setsecctx Casey Schaufler
2019-04-22 13:13   ` Tetsuo Handa
2019-04-22 20:45     ` Casey Schaufler
2019-04-22 21:01       ` Tetsuo Handa
2019-04-19  0:45 ` [PATCH 70/90] LSM: Correct handling of ENOSYS in inode_setxattr Casey Schaufler
2019-04-19  0:45 ` [PATCH 71/90] LSM: Infrastructure security blobs for mount options Casey Schaufler
2019-04-19  0:45 ` [PATCH 72/90] LSM: Fix for security_init_inode_security Casey Schaufler
2019-04-19  0:46 ` [PATCH 73/90] Smack: Advertise the secid to netlabel Casey Schaufler
2019-04-19  0:46 ` [PATCH 74/90] LSM: Change error detection for UDP peer security Casey Schaufler
2019-04-19  0:46 ` [PATCH 75/90] Smack: Fix setting of the CIPSO MLS_CAT flags Casey Schaufler
2019-04-19  0:46 ` [PATCH 76/90] Smack: Set netlabel flags properly on new label import Casey Schaufler
2019-04-19  0:46 ` [PATCH 77/90] Netlabel: Add a secattr comparison API function Casey Schaufler
2019-04-19  0:46 ` [PATCH 78/90] Smack: Let netlabel do the work on the ambient domain Casey Schaufler
2019-04-19  0:46 ` [PATCH 79/90] Smack: Don't set the socket label on each send Casey Schaufler
2019-04-19  0:46 ` [PATCH 80/90] Smack: Let netlabel do the work on connections Casey Schaufler
2019-04-19  0:46 ` [PATCH 81/90] Netlabel: Return the labeling type on socket Casey Schaufler
2019-04-19 15:27 ` [PATCH 00/90] LSM: Module stacking for all Stephen Smalley
2019-04-21 17:31   ` Casey Schaufler
2019-04-22 12:46     ` Stephen Smalley
2019-04-22 16:10       ` Casey Schaufler

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