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authorLinus Torvalds <torvalds@linux-foundation.org>2020-10-13 16:18:51 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-13 16:18:51 -0700
commit99a6740f88e9438cd220096d3d96eb6ba8d5c6f0 (patch)
treef11cc7eaae9fdac6f1dcfbe4045e71caf72b6fbe /security/smack
parentb274279a0b0c4a52ad9cd4894fce0df8d52e8e64 (diff)
parentedd615371b668404d06699c04f5f90c4f438814a (diff)
Merge tag 'Smack-for-5.10' of git://github.com/cschaufler/smack-next
Pull smack updates from Casey Schaufler: "Two minor fixes and one performance enhancement to Smack. The performance improvement is significant and the new code is more like its counterpart in SELinux. - Two kernel test robot suggested clean-ups. - Teach Smack to use the IPv4 netlabel cache. This results in a 12-14% improvement on TCP benchmarks" * tag 'Smack-for-5.10' of git://github.com/cschaufler/smack-next: Smack: Remove unnecessary variable initialization Smack: Fix build when NETWORK_SECMARK is not set Smack: Use the netlabel cache Smack: Set socket labels only once Smack: Consolidate uses of secmark into a function
Diffstat (limited to 'security/smack')
-rw-r--r--security/smack/smack.h19
-rw-r--r--security/smack/smack_access.c55
-rw-r--r--security/smack/smack_lsm.c252
-rw-r--r--security/smack/smackfs.c23
4 files changed, 200 insertions, 149 deletions
diff --git a/security/smack/smack.h b/security/smack/smack.h
index e9e817d09785..a9768b12716b 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -100,7 +100,12 @@ struct socket_smack {
struct smack_known *smk_out; /* outbound label */
struct smack_known *smk_in; /* inbound label */
struct smack_known *smk_packet; /* TCP peer label */
+ int smk_state; /* netlabel socket states */
};
+#define SMK_NETLBL_UNSET 0
+#define SMK_NETLBL_UNLABELED 1
+#define SMK_NETLBL_LABELED 2
+#define SMK_NETLBL_REQSKB 3
/*
* Inode smack data
@@ -197,19 +202,6 @@ enum {
#define SMACK_CIPSO_OPTION "-CIPSO"
/*
- * How communications on this socket are treated.
- * Usually it's determined by the underlying netlabel code
- * but there are certain cases, including single label hosts
- * and potentially single label interfaces for which the
- * treatment can not be known in advance.
- *
- * The possibility of additional labeling schemes being
- * introduced in the future exists as well.
- */
-#define SMACK_UNLABELED_SOCKET 0
-#define SMACK_CIPSO_SOCKET 1
-
-/*
* CIPSO defaults.
*/
#define SMACK_CIPSO_DOI_DEFAULT 3 /* Historical */
@@ -305,6 +297,7 @@ struct smack_known *smk_find_entry(const char *);
bool smack_privileged(int cap);
bool smack_privileged_cred(int cap, const struct cred *cred);
void smk_destroy_label_list(struct list_head *list);
+int smack_populate_secattr(struct smack_known *skp);
/*
* Shared data.
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index 38ac3da4e791..efe2406a3960 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -511,6 +511,42 @@ int smk_netlbl_mls(int level, char *catset, struct netlbl_lsm_secattr *sap,
}
/**
+ * smack_populate_secattr - fill in the smack_known netlabel information
+ * @skp: pointer to the structure to fill
+ *
+ * Populate the netlabel secattr structure for a Smack label.
+ *
+ * Returns 0 unless creating the category mapping fails
+ */
+int smack_populate_secattr(struct smack_known *skp)
+{
+ int slen;
+
+ skp->smk_netlabel.attr.secid = skp->smk_secid;
+ skp->smk_netlabel.domain = skp->smk_known;
+ skp->smk_netlabel.cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
+ if (skp->smk_netlabel.cache != NULL) {
+ skp->smk_netlabel.flags |= NETLBL_SECATTR_CACHE;
+ skp->smk_netlabel.cache->free = NULL;
+ skp->smk_netlabel.cache->data = skp;
+ }
+ skp->smk_netlabel.flags |= NETLBL_SECATTR_SECID |
+ NETLBL_SECATTR_MLS_LVL |
+ NETLBL_SECATTR_DOMAIN;
+ /*
+ * If direct labeling works use it.
+ * Otherwise use mapped labeling.
+ */
+ slen = strlen(skp->smk_known);
+ if (slen < SMK_CIPSOLEN)
+ return smk_netlbl_mls(smack_cipso_direct, skp->smk_known,
+ &skp->smk_netlabel, slen);
+
+ return smk_netlbl_mls(smack_cipso_mapped, (char *)&skp->smk_secid,
+ &skp->smk_netlabel, sizeof(skp->smk_secid));
+}
+
+/**
* smk_import_entry - import a label, return the list entry
* @string: a text string that might be a Smack label
* @len: the maximum size, or zero if it is NULL terminated.
@@ -523,7 +559,6 @@ struct smack_known *smk_import_entry(const char *string, int len)
{
struct smack_known *skp;
char *smack;
- int slen;
int rc;
smack = smk_parse_smack(string, len);
@@ -544,21 +579,8 @@ struct smack_known *smk_import_entry(const char *string, int len)
skp->smk_known = smack;
skp->smk_secid = smack_next_secid++;
- skp->smk_netlabel.domain = skp->smk_known;
- skp->smk_netlabel.flags =
- NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
- /*
- * If direct labeling works use it.
- * Otherwise use mapped labeling.
- */
- slen = strlen(smack);
- if (slen < SMK_CIPSOLEN)
- rc = smk_netlbl_mls(smack_cipso_direct, skp->smk_known,
- &skp->smk_netlabel, slen);
- else
- rc = smk_netlbl_mls(smack_cipso_mapped, (char *)&skp->smk_secid,
- &skp->smk_netlabel, sizeof(skp->smk_secid));
+ rc = smack_populate_secattr(skp);
if (rc >= 0) {
INIT_LIST_HEAD(&skp->smk_rules);
mutex_init(&skp->smk_rules_lock);
@@ -569,9 +591,6 @@ struct smack_known *smk_import_entry(const char *string, int len)
smk_insert_entry(skp);
goto unlockout;
}
- /*
- * smk_netlbl_mls failed.
- */
kfree(skp);
skp = ERR_PTR(rc);
freeout:
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 8c0893eb5aa8..5c90b9fa4d40 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -2383,38 +2383,31 @@ static struct smack_known *smack_ipv6host_label(struct sockaddr_in6 *sip)
}
/**
- * smack_netlabel - Set the secattr on a socket
+ * smack_netlbl_add - Set the secattr on a socket
* @sk: the socket
- * @labeled: socket label scheme
*
- * Convert the outbound smack value (smk_out) to a
- * secattr and attach it to the socket.
+ * Attach the outbound smack value (smk_out) to the socket.
*
* Returns 0 on success or an error code
*/
-static int smack_netlabel(struct sock *sk, int labeled)
+static int smack_netlbl_add(struct sock *sk)
{
- struct smack_known *skp;
struct socket_smack *ssp = sk->sk_security;
- int rc = 0;
+ struct smack_known *skp = ssp->smk_out;
+ int rc;
- /*
- * Usually the netlabel code will handle changing the
- * packet labeling based on the label.
- * The case of a single label host is different, because
- * a single label host should never get a labeled packet
- * even though the label is usually associated with a packet
- * label.
- */
local_bh_disable();
bh_lock_sock_nested(sk);
- if (ssp->smk_out == smack_net_ambient ||
- labeled == SMACK_UNLABELED_SOCKET)
- netlbl_sock_delattr(sk);
- else {
- skp = ssp->smk_out;
- rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
+ rc = netlbl_sock_setattr(sk, sk->sk_family, &skp->smk_netlabel);
+ switch (rc) {
+ case 0:
+ ssp->smk_state = SMK_NETLBL_LABELED;
+ break;
+ case -EDESTADDRREQ:
+ ssp->smk_state = SMK_NETLBL_REQSKB;
+ rc = 0;
+ break;
}
bh_unlock_sock(sk);
@@ -2424,7 +2417,31 @@ static int smack_netlabel(struct sock *sk, int labeled)
}
/**
- * smack_netlbel_send - Set the secattr on a socket and perform access checks
+ * smack_netlbl_delete - Remove the secattr from a socket
+ * @sk: the socket
+ *
+ * Remove the outbound smack value from a socket
+ */
+static void smack_netlbl_delete(struct sock *sk)
+{
+ struct socket_smack *ssp = sk->sk_security;
+
+ /*
+ * Take the label off the socket if one is set.
+ */
+ if (ssp->smk_state != SMK_NETLBL_LABELED)
+ return;
+
+ local_bh_disable();
+ bh_lock_sock_nested(sk);
+ netlbl_sock_delattr(sk);
+ bh_unlock_sock(sk);
+ local_bh_enable();
+ ssp->smk_state = SMK_NETLBL_UNLABELED;
+}
+
+/**
+ * smk_ipv4_check - Perform IPv4 host access checks
* @sk: the socket
* @sap: the destination address
*
@@ -2434,11 +2451,10 @@ static int smack_netlabel(struct sock *sk, int labeled)
* Returns 0 on success or an error code.
*
*/
-static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
+static int smk_ipv4_check(struct sock *sk, struct sockaddr_in *sap)
{
struct smack_known *skp;
- int rc;
- int sk_lbl;
+ int rc = 0;
struct smack_known *hkp;
struct socket_smack *ssp = sk->sk_security;
struct smk_audit_info ad;
@@ -2454,19 +2470,18 @@ static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap)
ad.a.u.net->dport = sap->sin_port;
ad.a.u.net->v4info.daddr = sap->sin_addr.s_addr;
#endif
- sk_lbl = SMACK_UNLABELED_SOCKET;
skp = ssp->smk_out;
rc = smk_access(skp, hkp, MAY_WRITE, &ad);
rc = smk_bu_note("IPv4 host check", skp, hkp, MAY_WRITE, rc);
- } else {
- sk_lbl = SMACK_CIPSO_SOCKET;
- rc = 0;
+ /*
+ * Clear the socket netlabel if it's set.
+ */
+ if (!rc)
+ smack_netlbl_delete(sk);
}
rcu_read_unlock();
- if (rc != 0)
- return rc;
- return smack_netlabel(sk, sk_lbl);
+ return rc;
}
/**
@@ -2703,7 +2718,7 @@ static int smack_inode_setsecurity(struct inode *inode, const char *name,
else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
ssp->smk_out = skp;
if (sock->sk->sk_family == PF_INET) {
- rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
+ rc = smack_netlbl_add(sock->sk);
if (rc != 0)
printk(KERN_WARNING
"Smack: \"%s\" netlbl error %d.\n",
@@ -2754,7 +2769,7 @@ static int smack_socket_post_create(struct socket *sock, int family,
/*
* Set the outbound netlbl.
*/
- return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET);
+ return smack_netlbl_add(sock->sk);
}
/**
@@ -2845,7 +2860,7 @@ static int smack_socket_connect(struct socket *sock, struct sockaddr *sap,
}
if (sap->sa_family != AF_INET || addrlen < sizeof(struct sockaddr_in))
return 0;
- rc = smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap);
+ rc = smk_ipv4_check(sock->sk, (struct sockaddr_in *)sap);
return rc;
}
@@ -3663,7 +3678,7 @@ static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg,
if (msg->msg_namelen < sizeof(struct sockaddr_in) ||
sip->sin_family != AF_INET)
return -EINVAL;
- rc = smack_netlabel_send(sock->sk, sip);
+ rc = smk_ipv4_check(sock->sk, sip);
break;
#if IS_ENABLED(CONFIG_IPV6)
case AF_INET6:
@@ -3700,6 +3715,18 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
int acat;
int kcat;
+ /*
+ * Netlabel found it in the cache.
+ */
+ if ((sap->flags & NETLBL_SECATTR_CACHE) != 0)
+ return (struct smack_known *)sap->cache->data;
+
+ if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
+ /*
+ * Looks like a fallback, which gives us a secid.
+ */
+ return smack_from_secid(sap->attr.secid);
+
if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) {
/*
* Looks like a CIPSO packet.
@@ -3747,11 +3774,6 @@ static struct smack_known *smack_from_secattr(struct netlbl_lsm_secattr *sap,
return &smack_known_web;
return &smack_known_star;
}
- if ((sap->flags & NETLBL_SECATTR_SECID) != 0)
- /*
- * Looks like a fallback, which gives us a secid.
- */
- return smack_from_secid(sap->attr.secid);
/*
* Without guidance regarding the smack value
* for the packet fall back on the network
@@ -3811,6 +3833,62 @@ static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
#endif /* CONFIG_IPV6 */
/**
+ * smack_from_skb - Smack data from the secmark in an skb
+ * @skb: packet
+ *
+ * Returns smack_known of the secmark or NULL if that won't work.
+ */
+#ifdef CONFIG_NETWORK_SECMARK
+static struct smack_known *smack_from_skb(struct sk_buff *skb)
+{
+ if (skb == NULL || skb->secmark == 0)
+ return NULL;
+
+ return smack_from_secid(skb->secmark);
+}
+#else
+static inline struct smack_known *smack_from_skb(struct sk_buff *skb)
+{
+ return NULL;
+}
+#endif
+
+/**
+ * smack_from_netlbl - Smack data from the IP options in an skb
+ * @sk: socket data came in on
+ * @family: address family
+ * @skb: packet
+ *
+ * Find the Smack label in the IP options. If it hasn't been
+ * added to the netlabel cache, add it here.
+ *
+ * Returns smack_known of the IP options or NULL if that won't work.
+ */
+static struct smack_known *smack_from_netlbl(struct sock *sk, u16 family,
+ struct sk_buff *skb)
+{
+ struct netlbl_lsm_secattr secattr;
+ struct socket_smack *ssp = NULL;
+ struct smack_known *skp = NULL;
+ int rc;
+
+ netlbl_secattr_init(&secattr);
+
+ if (sk)
+ ssp = sk->sk_security;
+
+ if (netlbl_skbuff_getattr(skb, family, &secattr) == 0) {
+ skp = smack_from_secattr(&secattr, ssp);
+ if (secattr.flags & NETLBL_SECATTR_CACHEABLE)
+ rc = netlbl_cache_add(skb, family, &skp->smk_netlabel);
+ }
+
+ netlbl_secattr_destroy(&secattr);
+
+ return skp;
+}
+
+/**
* smack_socket_sock_rcv_skb - Smack packet delivery access check
* @sk: socket
* @skb: packet
@@ -3819,7 +3897,6 @@ static int smk_skb_to_addr_ipv6(struct sk_buff *skb, struct sockaddr_in6 *sip)
*/
static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
- struct netlbl_lsm_secattr secattr;
struct socket_smack *ssp = sk->sk_security;
struct smack_known *skp = NULL;
int rc = 0;
@@ -3838,33 +3915,18 @@ 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.
* The secmark is assumed to reflect policy better.
*/
- if (skb && skb->secmark != 0) {
- skp = smack_from_secid(skb->secmark);
- goto access_check;
+ skp = smack_from_skb(skb);
+ if (skp == NULL) {
+ skp = smack_from_netlbl(sk, family, skb);
+ if (skp == NULL)
+ skp = smack_net_ambient;
}
-#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
- /*
- * Translate what netlabel gave us.
- */
- netlbl_secattr_init(&secattr);
- rc = netlbl_skbuff_getattr(skb, family, &secattr);
- if (rc == 0)
- skp = smack_from_secattr(&secattr, ssp);
- else
- skp = smack_net_ambient;
-
- 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;
@@ -3890,16 +3952,14 @@ access_check:
proto != IPPROTO_TCP && proto != IPPROTO_DCCP)
break;
#ifdef SMACK_IPV6_SECMARK_LABELING
- if (skb && skb->secmark != 0)
- skp = smack_from_secid(skb->secmark);
- else if (smk_ipv6_localhost(&sadd))
- break;
- else
+ skp = smack_from_skb(skb);
+ if (skp == NULL) {
+ if (smk_ipv6_localhost(&sadd))
+ break;
skp = smack_ipv6host_label(&sadd);
- if (skp == NULL)
- skp = smack_net_ambient;
- if (skb == NULL)
- break;
+ if (skp == NULL)
+ skp = smack_net_ambient;
+ }
#ifdef CONFIG_AUDIT
smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
ad.a.u.net->family = family;
@@ -3971,12 +4031,11 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
struct sk_buff *skb, u32 *secid)
{
- struct netlbl_lsm_secattr secattr;
struct socket_smack *ssp = NULL;
struct smack_known *skp;
+ struct sock *sk = NULL;
int family = PF_UNSPEC;
u32 s = 0; /* 0 is the invalid secid */
- int rc;
if (skb != NULL) {
if (skb->protocol == htons(ETH_P_IP))
@@ -3995,27 +4054,25 @@ static int smack_socket_getpeersec_dgram(struct socket *sock,
s = ssp->smk_out->smk_secid;
break;
case PF_INET:
-#ifdef CONFIG_SECURITY_SMACK_NETFILTER
- s = skb->secmark;
- if (s != 0)
+ skp = smack_from_skb(skb);
+ if (skp) {
+ s = skp->smk_secid;
break;
-#endif
+ }
/*
* Translate what netlabel gave us.
*/
- if (sock != NULL && sock->sk != NULL)
- ssp = sock->sk->sk_security;
- netlbl_secattr_init(&secattr);
- rc = netlbl_skbuff_getattr(skb, family, &secattr);
- if (rc == 0) {
- skp = smack_from_secattr(&secattr, ssp);
+ if (sock != NULL)
+ sk = sock->sk;
+ skp = smack_from_netlbl(sk, family, skb);
+ if (skp != NULL)
s = skp->smk_secid;
- }
- netlbl_secattr_destroy(&secattr);
break;
case PF_INET6:
#ifdef SMACK_IPV6_SECMARK_LABELING
- s = skb->secmark;
+ skp = smack_from_skb(skb);
+ if (skp)
+ s = skp->smk_secid;
#endif
break;
}
@@ -4063,7 +4120,6 @@ static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
u16 family = sk->sk_family;
struct smack_known *skp;
struct socket_smack *ssp = sk->sk_security;
- struct netlbl_lsm_secattr secattr;
struct sockaddr_in addr;
struct iphdr *hdr;
struct smack_known *hskp;
@@ -4087,29 +4143,17 @@ 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.
* The secmark is assumed to reflect policy better.
*/
- if (skb && skb->secmark != 0) {
- skp = smack_from_secid(skb->secmark);
- goto access_check;
+ skp = smack_from_skb(skb);
+ if (skp == NULL) {
+ skp = smack_from_netlbl(sk, family, skb);
+ if (skp == NULL)
+ skp = &smack_known_huh;
}
-#endif /* CONFIG_SECURITY_SMACK_NETFILTER */
-
- netlbl_secattr_init(&secattr);
- rc = netlbl_skbuff_getattr(skb, family, &secattr);
- if (rc == 0)
- skp = smack_from_secattr(&secattr, ssp);
- else
- 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);
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 9c4308077574..e567b4baf3a0 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -922,6 +922,10 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
skp->smk_netlabel.attr.mls.cat = ncats.attr.mls.cat;
skp->smk_netlabel.attr.mls.lvl = ncats.attr.mls.lvl;
rc = count;
+ /*
+ * This mapping may have been cached, so clear the cache.
+ */
+ netlbl_cache_invalidate();
}
out:
@@ -2950,15 +2954,6 @@ static struct file_system_type smk_fs_type = {
static struct vfsmount *smackfs_mount;
-static int __init smk_preset_netlabel(struct smack_known *skp)
-{
- skp->smk_netlabel.domain = skp->smk_known;
- skp->smk_netlabel.flags =
- NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
- return smk_netlbl_mls(smack_cipso_direct, skp->smk_known,
- &skp->smk_netlabel, strlen(skp->smk_known));
-}
-
/**
* init_smk_fs - get the smackfs superblock
*
@@ -2997,19 +2992,19 @@ static int __init init_smk_fs(void)
smk_cipso_doi();
smk_unlbl_ambient(NULL);
- rc = smk_preset_netlabel(&smack_known_floor);
+ rc = smack_populate_secattr(&smack_known_floor);
if (err == 0 && rc < 0)
err = rc;
- rc = smk_preset_netlabel(&smack_known_hat);
+ rc = smack_populate_secattr(&smack_known_hat);
if (err == 0 && rc < 0)
err = rc;
- rc = smk_preset_netlabel(&smack_known_huh);
+ rc = smack_populate_secattr(&smack_known_huh);
if (err == 0 && rc < 0)
err = rc;
- rc = smk_preset_netlabel(&smack_known_star);
+ rc = smack_populate_secattr(&smack_known_star);
if (err == 0 && rc < 0)
err = rc;
- rc = smk_preset_netlabel(&smack_known_web);
+ rc = smack_populate_secattr(&smack_known_web);
if (err == 0 && rc < 0)
err = rc;