diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-13 16:18:51 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-13 16:18:51 -0700 |
commit | 99a6740f88e9438cd220096d3d96eb6ba8d5c6f0 (patch) | |
tree | f11cc7eaae9fdac6f1dcfbe4045e71caf72b6fbe /security/smack | |
parent | b274279a0b0c4a52ad9cd4894fce0df8d52e8e64 (diff) | |
parent | edd615371b668404d06699c04f5f90c4f438814a (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.h | 19 | ||||
-rw-r--r-- | security/smack/smack_access.c | 55 | ||||
-rw-r--r-- | security/smack/smack_lsm.c | 252 | ||||
-rw-r--r-- | security/smack/smackfs.c | 23 |
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; |