diff options
Diffstat (limited to 'security/selinux/ss/services.c')
| -rw-r--r-- | security/selinux/ss/services.c | 448 |
1 files changed, 261 insertions, 187 deletions
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 18274b00509..bdb7070dd3d 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -17,9 +17,13 @@ * * Added support for NetLabel * + * Updated: Chad Sellers <csellers@tresys.com> + * + * Added validation of kernel classes and permissions + * * Copyright (C) 2006 Hewlett-Packard Development Company, L.P. * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc. - * Copyright (C) 2003 - 2004 Tresys Technology, LLC + * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com> * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -29,6 +33,7 @@ #include <linux/slab.h> #include <linux/string.h> #include <linux/spinlock.h> +#include <linux/rcupdate.h> #include <linux/errno.h> #include <linux/in.h> #include <linux/sched.h> @@ -49,10 +54,17 @@ #include "mls.h" #include "objsec.h" #include "selinux_netlabel.h" +#include "xfrm.h" +#include "ebitmap.h" extern void selnl_notify_policyload(u32 seqno); unsigned int policydb_loaded_version; +/* + * This is declared in avc.c + */ +extern const struct selinux_class_perm selinux_class_perm; + static DEFINE_RWLOCK(policy_rwlock); #define POLICY_RDLOCK read_lock(&policy_rwlock) #define POLICY_WRLOCK write_lock_irq(&policy_rwlock) @@ -1019,86 +1031,112 @@ int security_change_sid(u32 ssid, } /* - * Verify that each permission that is defined under the - * existing policy is still defined with the same value - * in the new policy. - */ -static int validate_perm(void *key, void *datum, void *p) -{ - struct hashtab *h; - struct perm_datum *perdatum, *perdatum2; - int rc = 0; - - - h = p; - perdatum = datum; - - perdatum2 = hashtab_search(h, key); - if (!perdatum2) { - printk(KERN_ERR "security: permission %s disappeared", - (char *)key); - rc = -ENOENT; - goto out; - } - if (perdatum->value != perdatum2->value) { - printk(KERN_ERR "security: the value of permission %s changed", - (char *)key); - rc = -EINVAL; - } -out: - return rc; -} - -/* - * Verify that each class that is defined under the - * existing policy is still defined with the same - * attributes in the new policy. + * Verify that each kernel class that is defined in the + * policy is correct */ -static int validate_class(void *key, void *datum, void *p) +static int validate_classes(struct policydb *p) { - struct policydb *newp; - struct class_datum *cladatum, *cladatum2; - int rc; - - newp = p; - cladatum = datum; - - cladatum2 = hashtab_search(newp->p_classes.table, key); - if (!cladatum2) { - printk(KERN_ERR "security: class %s disappeared\n", - (char *)key); - rc = -ENOENT; - goto out; - } - if (cladatum->value != cladatum2->value) { - printk(KERN_ERR "security: the value of class %s changed\n", - (char *)key); - rc = -EINVAL; - goto out; + int i, j; + struct class_datum *cladatum; + struct perm_datum *perdatum; + u32 nprim, tmp, common_pts_len, perm_val, pol_val; + u16 class_val; + const struct selinux_class_perm *kdefs = &selinux_class_perm; + const char *def_class, *def_perm, *pol_class; + struct symtab *perms; + + for (i = 1; i < kdefs->cts_len; i++) { + def_class = kdefs->class_to_string[i]; + if (i > p->p_classes.nprim) { + printk(KERN_INFO + "security: class %s not defined in policy\n", + def_class); + continue; + } + pol_class = p->p_class_val_to_name[i-1]; + if (strcmp(pol_class, def_class)) { + printk(KERN_ERR + "security: class %d is incorrect, found %s but should be %s\n", + i, pol_class, def_class); + return -EINVAL; + } } - if ((cladatum->comdatum && !cladatum2->comdatum) || - (!cladatum->comdatum && cladatum2->comdatum)) { - printk(KERN_ERR "security: the inherits clause for the access " - "vector definition for class %s changed\n", (char *)key); - rc = -EINVAL; - goto out; + for (i = 0; i < kdefs->av_pts_len; i++) { + class_val = kdefs->av_perm_to_string[i].tclass; + perm_val = kdefs->av_perm_to_string[i].value; + def_perm = kdefs->av_perm_to_string[i].name; + if (class_val > p->p_classes.nprim) + continue; + pol_class = p->p_class_val_to_name[class_val-1]; + cladatum = hashtab_search(p->p_classes.table, pol_class); + BUG_ON(!cladatum); + perms = &cladatum->permissions; + nprim = 1 << (perms->nprim - 1); + if (perm_val > nprim) { + printk(KERN_INFO + "security: permission %s in class %s not defined in policy\n", + def_perm, pol_class); + continue; + } + perdatum = hashtab_search(perms->table, def_perm); + if (perdatum == NULL) { + printk(KERN_ERR + "security: permission %s in class %s not found in policy\n", + def_perm, pol_class); + return -EINVAL; + } + pol_val = 1 << (perdatum->value - 1); + if (pol_val != perm_val) { + printk(KERN_ERR + "security: permission %s in class %s has incorrect value\n", + def_perm, pol_class); + return -EINVAL; + } } - if (cladatum->comdatum) { - rc = hashtab_map(cladatum->comdatum->permissions.table, validate_perm, - cladatum2->comdatum->permissions.table); - if (rc) { - printk(" in the access vector definition for class " - "%s\n", (char *)key); - goto out; + for (i = 0; i < kdefs->av_inherit_len; i++) { + class_val = kdefs->av_inherit[i].tclass; + if (class_val > p->p_classes.nprim) + continue; + pol_class = p->p_class_val_to_name[class_val-1]; + cladatum = hashtab_search(p->p_classes.table, pol_class); + BUG_ON(!cladatum); + if (!cladatum->comdatum) { + printk(KERN_ERR + "security: class %s should have an inherits clause but does not\n", + pol_class); + return -EINVAL; + } + tmp = kdefs->av_inherit[i].common_base; + common_pts_len = 0; + while (!(tmp & 0x01)) { + common_pts_len++; + tmp >>= 1; + } + perms = &cladatum->comdatum->permissions; + for (j = 0; j < common_pts_len; j++) { + def_perm = kdefs->av_inherit[i].common_pts[j]; + if (j >= perms->nprim) { + printk(KERN_INFO + "security: permission %s in class %s not defined in policy\n", + def_perm, pol_class); + continue; + } + perdatum = hashtab_search(perms->table, def_perm); + if (perdatum == NULL) { + printk(KERN_ERR + "security: permission %s in class %s not found in policy\n", + def_perm, pol_class); + return -EINVAL; + } + if (perdatum->value != j + 1) { + printk(KERN_ERR + "security: permission %s in class %s has incorrect value\n", + def_perm, pol_class); + return -EINVAL; + } } } - rc = hashtab_map(cladatum->permissions.table, validate_perm, - cladatum2->permissions.table); - if (rc) - printk(" in access vector definition for class %s\n", - (char *)key); -out: - return rc; + return 0; } /* Clone the SID into the new SID table. */ @@ -1243,6 +1281,16 @@ int security_load_policy(void *data, size_t len) avtab_cache_destroy(); return -EINVAL; } + /* Verify that the kernel defined classes are correct. */ + if (validate_classes(&policydb)) { + printk(KERN_ERR + "security: the definition of a class is incorrect\n"); + LOAD_UNLOCK; + sidtab_destroy(&sidtab); + policydb_destroy(&policydb); + avtab_cache_destroy(); + return -EINVAL; + } policydb_loaded_version = policydb.policyvers; ss_initialized = 1; seqno = ++latest_granting; @@ -1265,10 +1313,10 @@ int security_load_policy(void *data, size_t len) sidtab_init(&newsidtab); - /* Verify that the existing classes did not change. */ - if (hashtab_map(policydb.p_classes.table, validate_class, &newpolicydb)) { - printk(KERN_ERR "security: the definition of an existing " - "class changed\n"); + /* Verify that the kernel defined classes are correct. */ + if (validate_classes(&newpolicydb)) { + printk(KERN_ERR + "security: the definition of a class is incorrect\n"); rc = -EINVAL; goto err; } @@ -2145,6 +2193,32 @@ void selinux_audit_set_callback(int (*callback)(void)) aurule_callback = callback; } +/** + * security_skb_extlbl_sid - Determine the external label of a packet + * @skb: the packet + * @base_sid: the SELinux SID to use as a context for MLS only external labels + * @sid: the packet's SID + * + * Description: + * Check the various different forms of external packet labeling and determine + * the external SID for the packet. + * + */ +void security_skb_extlbl_sid(struct sk_buff *skb, u32 base_sid, u32 *sid) +{ + u32 xfrm_sid; + u32 nlbl_sid; + + selinux_skb_xfrm_sid(skb, &xfrm_sid); + if (selinux_netlbl_skbuff_getsid(skb, + (xfrm_sid == SECSID_NULL ? + base_sid : xfrm_sid), + &nlbl_sid) != 0) + nlbl_sid = SECSID_NULL; + + *sid = (nlbl_sid == SECSID_NULL ? xfrm_sid : nlbl_sid); +} + #ifdef CONFIG_NETLABEL /* * This is the structure we store inside the NetLabel cache block. @@ -2209,8 +2283,6 @@ static void selinux_netlbl_cache_add(struct sk_buff *skb, struct context *ctx) cache = kzalloc(sizeof(*cache), GFP_ATOMIC); if (cache == NULL) goto netlbl_cache_add_return; - secattr.cache->free = selinux_netlbl_cache_free; - secattr.cache->data = (void *)cache; cache->type = NETLBL_CACHE_T_MLS; if (ebitmap_cpy(&cache->data.mls_label.level[0].cat, @@ -2223,6 +2295,10 @@ static void selinux_netlbl_cache_add(struct sk_buff *skb, struct context *ctx) cache->data.mls_label.level[0].sens = ctx->range.level[0].sens; cache->data.mls_label.level[1].sens = ctx->range.level[0].sens; + secattr.cache->free = selinux_netlbl_cache_free; + secattr.cache->data = (void *)cache; + secattr.flags = NETLBL_SECATTR_CACHE; + netlbl_cache_add(skb, &secattr); netlbl_cache_add_return: @@ -2268,7 +2344,7 @@ static int selinux_netlbl_secattr_to_sid(struct sk_buff *skb, POLICY_RDLOCK; - if (secattr->cache) { + if (secattr->flags & NETLBL_SECATTR_CACHE) { cache = NETLBL_CACHE(secattr->cache->data); switch (cache->type) { case NETLBL_CACHE_T_SID: @@ -2301,7 +2377,7 @@ static int selinux_netlbl_secattr_to_sid(struct sk_buff *skb, default: goto netlbl_secattr_to_sid_return; } - } else if (secattr->mls_lvl_vld) { + } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) { ctx = sidtab_search(&sidtab, base_sid); if (ctx == NULL) goto netlbl_secattr_to_sid_return; @@ -2309,13 +2385,10 @@ static int selinux_netlbl_secattr_to_sid(struct sk_buff *skb, ctx_new.user = ctx->user; ctx_new.role = ctx->role; ctx_new.type = ctx->type; - mls_import_lvl(&ctx_new, secattr->mls_lvl, secattr->mls_lvl); - if (secattr->mls_cat) { - if (mls_import_cat(&ctx_new, - secattr->mls_cat, - secattr->mls_cat_len, - NULL, - 0) != 0) + mls_import_netlbl_lvl(&ctx_new, secattr); + if (secattr->flags & NETLBL_SECATTR_MLS_CAT) { + if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat, + secattr->mls_cat) != 0) goto netlbl_secattr_to_sid_return; ctx_new.range.level[1].cat.highbit = ctx_new.range.level[0].cat.highbit; @@ -2360,20 +2433,20 @@ netlbl_secattr_to_sid_return_cleanup: * assign to the packet. Returns zero on success, negative values on failure. * */ -static int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, - u32 base_sid, - u32 *sid) +int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, u32 base_sid, u32 *sid) { int rc; struct netlbl_lsm_secattr secattr; netlbl_secattr_init(&secattr); rc = netlbl_skbuff_getattr(skb, &secattr); - if (rc == 0) + if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) rc = selinux_netlbl_secattr_to_sid(skb, &secattr, base_sid, sid); + else + *sid = SECSID_NULL; netlbl_secattr_destroy(&secattr); return rc; @@ -2386,7 +2459,9 @@ static int selinux_netlbl_skbuff_getsid(struct sk_buff *skb, * * Description: * Attempt to label a socket using the NetLabel mechanism using the given - * SID. Returns zero values on success, negative values on failure. + * SID. Returns zero values on success, negative values on failure. The + * caller is responsibile for calling rcu_read_lock() before calling this + * this function and rcu_read_unlock() after this function returns. * */ static int selinux_netlbl_socket_setsid(struct socket *sock, u32 sid) @@ -2399,35 +2474,55 @@ static int selinux_netlbl_socket_setsid(struct socket *sock, u32 sid) if (!ss_initialized) return 0; + netlbl_secattr_init(&secattr); + POLICY_RDLOCK; ctx = sidtab_search(&sidtab, sid); if (ctx == NULL) goto netlbl_socket_setsid_return; - netlbl_secattr_init(&secattr); secattr.domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1], GFP_ATOMIC); - mls_export_lvl(ctx, &secattr.mls_lvl, NULL); - secattr.mls_lvl_vld = 1; - mls_export_cat(ctx, - &secattr.mls_cat, - &secattr.mls_cat_len, - NULL, - NULL); + secattr.flags |= NETLBL_SECATTR_DOMAIN; + mls_export_netlbl_lvl(ctx, &secattr); + rc = mls_export_netlbl_cat(ctx, &secattr); + if (rc != 0) + goto netlbl_socket_setsid_return; rc = netlbl_socket_setattr(sock, &secattr); - if (rc == 0) + if (rc == 0) { + spin_lock(&sksec->nlbl_lock); sksec->nlbl_state = NLBL_LABELED; - - netlbl_secattr_destroy(&secattr); + spin_unlock(&sksec->nlbl_lock); + } netlbl_socket_setsid_return: POLICY_RDUNLOCK; + netlbl_secattr_destroy(&secattr); return rc; } /** + * selinux_netlbl_sk_security_reset - Reset the NetLabel fields + * @ssec: the sk_security_struct + * @family: the socket family + * + * Description: + * Called when the NetLabel state of a sk_security_struct needs to be reset. + * The caller is responsibile for all the NetLabel sk_security_struct locking. + * + */ +void selinux_netlbl_sk_security_reset(struct sk_security_struct *ssec, + int family) +{ + if (family == PF_INET) + ssec->nlbl_state = NLBL_REQUIRE; + else + ssec->nlbl_state = NLBL_UNSET; +} + +/** * selinux_netlbl_sk_security_init - Setup the NetLabel fields * @ssec: the sk_security_struct * @family: the socket family @@ -2440,14 +2535,13 @@ netlbl_socket_setsid_return: void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec, int family) { - if (family == PF_INET) - ssec->nlbl_state = NLBL_REQUIRE; - else - ssec->nlbl_state = NLBL_UNSET; + /* No locking needed, we are the only one who has access to ssec */ + selinux_netlbl_sk_security_reset(ssec, family); + spin_lock_init(&ssec->nlbl_lock); } /** - * selinux_netlbl_sk_clone_security - Copy the NetLabel fields + * selinux_netlbl_sk_security_clone - Copy the NetLabel fields * @ssec: the original sk_security_struct * @newssec: the cloned sk_security_struct * @@ -2456,41 +2550,41 @@ void selinux_netlbl_sk_security_init(struct sk_security_struct *ssec, * @newssec. * */ -void selinux_netlbl_sk_clone_security(struct sk_security_struct *ssec, +void selinux_netlbl_sk_security_clone(struct sk_security_struct *ssec, struct sk_security_struct *newssec) { + /* We don't need to take newssec->nlbl_lock because we are the only + * thread with access to newssec, but we do need to take the RCU read + * lock as other threads could have access to ssec */ + rcu_read_lock(); + selinux_netlbl_sk_security_reset(newssec, ssec->sk->sk_family); newssec->sclass = ssec->sclass; - if (ssec->nlbl_state != NLBL_UNSET) - newssec->nlbl_state = NLBL_REQUIRE; - else - newssec->nlbl_state = NLBL_UNSET; + rcu_read_unlock(); } /** * selinux_netlbl_socket_post_create - Label a socket using NetLabel * @sock: the socket to label - * @sock_family: the socket family - * @sid: the SID to use * * Description: * Attempt to label a socket using the NetLabel mechanism using the given * SID. Returns zero values on success, negative values on failure. * */ -int selinux_netlbl_socket_post_create(struct socket *sock, - int sock_family, - u32 sid) +int selinux_netlbl_socket_post_create(struct socket *sock) { + int rc = 0; struct inode_security_struct *isec = SOCK_INODE(sock)->i_security; struct sk_security_struct *sksec = sock->sk->sk_security; sksec->sclass = isec->sclass; - if (sock_family != PF_INET) - return 0; + rcu_read_lock(); + if (sksec->nlbl_state == NLBL_REQUIRE) + rc = selinux_netlbl_socket_setsid(sock, sksec->sid); + rcu_read_unlock(); - sksec->nlbl_state = NLBL_REQUIRE; - return selinux_netlbl_socket_setsid(sock, sid); + return rc; } /** @@ -2512,11 +2606,16 @@ void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock) sksec->sclass = isec->sclass; - if (sk->sk_family != PF_INET) + rcu_read_lock(); + + if (sksec->nlbl_state != NLBL_REQUIRE) { + rcu_read_unlock(); return; + } netlbl_secattr_init(&secattr); if (netlbl_sock_getattr(sk, &secattr) == 0 && + secattr.flags != NETLBL_SECATTR_NONE && selinux_netlbl_secattr_to_sid(NULL, &secattr, SECINITSID_UNLABELED, @@ -2524,35 +2623,12 @@ void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock) sksec->peer_sid = nlbl_peer_sid; netlbl_secattr_destroy(&secattr); - sksec->nlbl_state = NLBL_REQUIRE; - /* Try to set the NetLabel on the socket to save time later, if we fail * here we will pick up the pieces in later calls to * selinux_netlbl_inode_permission(). */ selinux_netlbl_socket_setsid(sock, sksec->sid); -} -/** - * selinux_netlbl_inet_conn_request - Handle a new connection request - * @skb: the packet - * @sock_sid: the SID of the parent socket - * - * Description: - * If present, use the security attributes of the packet in @skb and the - * parent sock's SID to arrive at a SID for the new child sock. Returns the - * SID of the connection or SECSID_NULL on failure. - * - */ -u32 selinux_netlbl_inet_conn_request(struct sk_buff *skb, u32 sock_sid) -{ - int rc; - u32 peer_sid; - - rc = selinux_netlbl_skbuff_getsid(skb, sock_sid, &peer_sid); - if (rc != 0) - return SECSID_NULL; - - return peer_sid; + rcu_read_unlock(); } /** @@ -2570,25 +2646,24 @@ u32 selinux_netlbl_inet_conn_request(struct sk_buff *skb, u32 sock_sid) int selinux_netlbl_inode_permission(struct inode *inode, int mask) { int rc; - struct inode_security_struct *isec; struct sk_security_struct *sksec; struct socket *sock; - if (!S_ISSOCK(inode->i_mode)) + if (!S_ISSOCK(inode->i_mode) || + ((mask & (MAY_WRITE | MAY_APPEND)) == 0)) return 0; - sock = SOCKET_I(inode); - isec = inode->i_security; sksec = sock->sk->sk_security; - mutex_lock(&isec->lock); - if (unlikely(sksec->nlbl_state == NLBL_REQUIRE && - (mask & (MAY_WRITE | MAY_APPEND)))) { - lock_sock(sock->sk); - rc = selinux_netlbl_socket_setsid(sock, sksec->sid); - release_sock(sock->sk); - } else - rc = 0; - mutex_unlock(&isec->lock); + + rcu_read_lock(); + if (sksec->nlbl_state != NLBL_REQUIRE) { + rcu_read_unlock(); + return 0; + } + lock_sock(sock->sk); + rc = selinux_netlbl_socket_setsid(sock, sksec->sid); + release_sock(sock->sk); + rcu_read_unlock(); return rc; } @@ -2646,38 +2721,37 @@ int selinux_netlbl_sock_rcv_skb(struct sk_security_struct *sksec, } /** - * selinux_netlbl_socket_getpeersec_stream - Return the connected peer's SID + * selinux_netlbl_socket_setsockopt - Do not allow users to remove a NetLabel * @sock: the socket + * @level: the socket level or protocol + * @optname: the socket option name * * Description: - * Examine @sock to find the connected peer's SID. Returns the SID on success - * or SECSID_NULL on error. + * Check the setsockopt() call and if the user is trying to replace the IP + * options on a socket and a NetLabel is in place for the socket deny the + * access; otherwise allow the access. Returns zero when the access is + * allowed, -EACCES when denied, and other negative values on error. * */ -u32 selinux_netlbl_socket_getpeersec_stream(struct socket *sock) +int selinux_netlbl_socket_setsockopt(struct socket *sock, + int level, + int optname) { + int rc = 0; struct sk_security_struct *sksec = sock->sk->sk_security; - return sksec->peer_sid; -} - -/** - * selinux_netlbl_socket_getpeersec_dgram - Return the SID of a NetLabel packet - * @skb: the packet - * - * Description: - * Examine @skb to find the SID assigned to it by NetLabel. Returns the SID on - * success, SECSID_NULL on error. - * - */ -u32 selinux_netlbl_socket_getpeersec_dgram(struct sk_buff *skb) -{ - int peer_sid; + struct netlbl_lsm_secattr secattr; - if (selinux_netlbl_skbuff_getsid(skb, - SECINITSID_UNLABELED, - &peer_sid) != 0) - return SECSID_NULL; + rcu_read_lock(); + if (level == IPPROTO_IP && optname == IP_OPTIONS && + sksec->nlbl_state == NLBL_LABELED) { + netlbl_secattr_init(&secattr); + rc = netlbl_socket_getattr(sock, &secattr); + if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE) + rc = -EACCES; + netlbl_secattr_destroy(&secattr); + } + rcu_read_unlock(); - return peer_sid; + return rc; } #endif /* CONFIG_NETLABEL */ |