From a660bec1d84ad19a39e380af129e207b3b8f609e Mon Sep 17 00:00:00 2001 From: Richard Haines Date: Tue, 19 Nov 2013 17:34:23 -0500 Subject: [PATCH 01/13] SELinux: Update policy version to support constraints info Update the policy version (POLICYDB_VERSION_CONSTRAINT_NAMES) to allow holding of policy source info for constraints. Signed-off-by: Richard Haines Acked-by: Stephen Smalley Signed-off-by: Paul Moore --- security/selinux/include/security.h | 3 +- security/selinux/ss/constraint.h | 1 + security/selinux/ss/policydb.c | 96 ++++++++++++++++++++++++++--- security/selinux/ss/policydb.h | 11 ++++ 4 files changed, 101 insertions(+), 10 deletions(-) diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h index fe341ae37004..8ed8daf7f1ee 100644 --- a/security/selinux/include/security.h +++ b/security/selinux/include/security.h @@ -33,13 +33,14 @@ #define POLICYDB_VERSION_ROLETRANS 26 #define POLICYDB_VERSION_NEW_OBJECT_DEFAULTS 27 #define POLICYDB_VERSION_DEFAULT_TYPE 28 +#define POLICYDB_VERSION_CONSTRAINT_NAMES 29 /* Range of policy versions we understand*/ #define POLICYDB_VERSION_MIN POLICYDB_VERSION_BASE #ifdef CONFIG_SECURITY_SELINUX_POLICYDB_VERSION_MAX #define POLICYDB_VERSION_MAX CONFIG_SECURITY_SELINUX_POLICYDB_VERSION_MAX_VALUE #else -#define POLICYDB_VERSION_MAX POLICYDB_VERSION_DEFAULT_TYPE +#define POLICYDB_VERSION_MAX POLICYDB_VERSION_CONSTRAINT_NAMES #endif /* Mask for just the mount related flags */ diff --git a/security/selinux/ss/constraint.h b/security/selinux/ss/constraint.h index 149dda731fd3..96fd947c494b 100644 --- a/security/selinux/ss/constraint.h +++ b/security/selinux/ss/constraint.h @@ -48,6 +48,7 @@ struct constraint_expr { u32 op; /* operator */ struct ebitmap names; /* names */ + struct type_set *type_names; struct constraint_expr *next; /* next expression */ }; diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index f6195ebde3c9..dc4011643b55 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -143,6 +143,11 @@ static struct policydb_compat_info policydb_compat[] = { .sym_num = SYM_NUM, .ocon_num = OCON_NUM, }, + { + .version = POLICYDB_VERSION_CONSTRAINT_NAMES, + .sym_num = SYM_NUM, + .ocon_num = OCON_NUM, + }, }; static struct policydb_compat_info *policydb_lookup_compat(int version) @@ -613,6 +618,19 @@ static int common_destroy(void *key, void *datum, void *p) return 0; } +static void constraint_expr_destroy(struct constraint_expr *expr) +{ + if (expr) { + ebitmap_destroy(&expr->names); + if (expr->type_names) { + ebitmap_destroy(&expr->type_names->types); + ebitmap_destroy(&expr->type_names->negset); + kfree(expr->type_names); + } + kfree(expr); + } +} + static int cls_destroy(void *key, void *datum, void *p) { struct class_datum *cladatum; @@ -628,10 +646,9 @@ static int cls_destroy(void *key, void *datum, void *p) while (constraint) { e = constraint->expr; while (e) { - ebitmap_destroy(&e->names); etmp = e; e = e->next; - kfree(etmp); + constraint_expr_destroy(etmp); } ctemp = constraint; constraint = constraint->next; @@ -642,16 +659,14 @@ static int cls_destroy(void *key, void *datum, void *p) while (constraint) { e = constraint->expr; while (e) { - ebitmap_destroy(&e->names); etmp = e; e = e->next; - kfree(etmp); + constraint_expr_destroy(etmp); } ctemp = constraint; constraint = constraint->next; kfree(ctemp); } - kfree(cladatum->comkey); } kfree(datum); @@ -1156,8 +1171,34 @@ bad: return rc; } -static int read_cons_helper(struct constraint_node **nodep, int ncons, - int allowxtarget, void *fp) +static void type_set_init(struct type_set *t) +{ + ebitmap_init(&t->types); + ebitmap_init(&t->negset); +} + +static int type_set_read(struct type_set *t, void *fp) +{ + __le32 buf[1]; + int rc; + + if (ebitmap_read(&t->types, fp)) + return -EINVAL; + if (ebitmap_read(&t->negset, fp)) + return -EINVAL; + + rc = next_entry(buf, fp, sizeof(u32)); + if (rc < 0) + return -EINVAL; + t->flags = le32_to_cpu(buf[0]); + + return 0; +} + + +static int read_cons_helper(struct policydb *p, + struct constraint_node **nodep, + int ncons, int allowxtarget, void *fp) { struct constraint_node *c, *lc; struct constraint_expr *e, *le; @@ -1225,6 +1266,18 @@ static int read_cons_helper(struct constraint_node **nodep, int ncons, rc = ebitmap_read(&e->names, fp); if (rc) return rc; + if (p->policyvers >= + POLICYDB_VERSION_CONSTRAINT_NAMES) { + e->type_names = kzalloc(sizeof + (*e->type_names), + GFP_KERNEL); + if (!e->type_names) + return -ENOMEM; + type_set_init(e->type_names); + rc = type_set_read(e->type_names, fp); + if (rc) + return rc; + } break; default: return -EINVAL; @@ -1301,7 +1354,7 @@ static int class_read(struct policydb *p, struct hashtab *h, void *fp) goto bad; } - rc = read_cons_helper(&cladatum->constraints, ncons, 0, fp); + rc = read_cons_helper(p, &cladatum->constraints, ncons, 0, fp); if (rc) goto bad; @@ -1311,7 +1364,8 @@ static int class_read(struct policydb *p, struct hashtab *h, void *fp) if (rc) goto bad; ncons = le32_to_cpu(buf[0]); - rc = read_cons_helper(&cladatum->validatetrans, ncons, 1, fp); + rc = read_cons_helper(p, &cladatum->validatetrans, + ncons, 1, fp); if (rc) goto bad; } @@ -2753,6 +2807,24 @@ static int common_write(void *vkey, void *datum, void *ptr) return 0; } +static int type_set_write(struct type_set *t, void *fp) +{ + int rc; + __le32 buf[1]; + + if (ebitmap_write(&t->types, fp)) + return -EINVAL; + if (ebitmap_write(&t->negset, fp)) + return -EINVAL; + + buf[0] = cpu_to_le32(t->flags); + rc = put_entry(buf, sizeof(u32), 1, fp); + if (rc) + return -EINVAL; + + return 0; +} + static int write_cons_helper(struct policydb *p, struct constraint_node *node, void *fp) { @@ -2784,6 +2856,12 @@ static int write_cons_helper(struct policydb *p, struct constraint_node *node, rc = ebitmap_write(&e->names, fp); if (rc) return rc; + if (p->policyvers >= + POLICYDB_VERSION_CONSTRAINT_NAMES) { + rc = type_set_write(e->type_names, fp); + if (rc) + return rc; + } break; default: break; diff --git a/security/selinux/ss/policydb.h b/security/selinux/ss/policydb.h index da637471d4ce..725d5945a97e 100644 --- a/security/selinux/ss/policydb.h +++ b/security/selinux/ss/policydb.h @@ -153,6 +153,17 @@ struct cond_bool_datum { struct cond_node; +/* + * type set preserves data needed to determine constraint info from + * policy source. This is not used by the kernel policy but allows + * utilities such as audit2allow to determine constraint denials. + */ +struct type_set { + struct ebitmap types; + struct ebitmap negset; + u32 flags; +}; + /* * The configuration data includes security contexts for * initial SIDs, unlabeled file systems, TCP and UDP port numbers, From b5495b4217d3fa64deac479db83dbede149af7d8 Mon Sep 17 00:00:00 2001 From: Tim Gardner Date: Thu, 14 Nov 2013 15:04:51 -0700 Subject: [PATCH 02/13] SELinux: security_load_policy: Silence frame-larger-than warning Dynamically allocate a couple of the larger stack variables in order to reduce the stack footprint below 1024. gcc-4.8 security/selinux/ss/services.c: In function 'security_load_policy': security/selinux/ss/services.c:1964:1: warning: the frame size of 1104 bytes is larger than 1024 bytes [-Wframe-larger-than=] } Also silence a couple of checkpatch warnings at the same time. WARNING: sizeof policydb should be sizeof(policydb) + memcpy(oldpolicydb, &policydb, sizeof policydb); WARNING: sizeof policydb should be sizeof(policydb) + memcpy(&policydb, newpolicydb, sizeof policydb); Cc: Stephen Smalley Cc: James Morris Cc: Eric Paris Signed-off-by: Tim Gardner Signed-off-by: Paul Moore --- security/selinux/ss/services.c | 54 ++++++++++++++++++++-------------- 1 file changed, 32 insertions(+), 22 deletions(-) diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index ee470a0b5c27..6db5546717eb 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -1831,7 +1831,7 @@ static int security_preserve_bools(struct policydb *p); */ int security_load_policy(void *data, size_t len) { - struct policydb oldpolicydb, newpolicydb; + struct policydb *oldpolicydb, *newpolicydb; struct sidtab oldsidtab, newsidtab; struct selinux_mapping *oldmap, *map = NULL; struct convert_context_args args; @@ -1840,12 +1840,19 @@ int security_load_policy(void *data, size_t len) int rc = 0; struct policy_file file = { data, len }, *fp = &file; + oldpolicydb = kzalloc(2 * sizeof(*oldpolicydb), GFP_KERNEL); + if (!oldpolicydb) { + rc = -ENOMEM; + goto out; + } + newpolicydb = oldpolicydb + 1; + if (!ss_initialized) { avtab_cache_init(); rc = policydb_read(&policydb, fp); if (rc) { avtab_cache_destroy(); - return rc; + goto out; } policydb.len = len; @@ -1855,14 +1862,14 @@ int security_load_policy(void *data, size_t len) if (rc) { policydb_destroy(&policydb); avtab_cache_destroy(); - return rc; + goto out; } rc = policydb_load_isids(&policydb, &sidtab); if (rc) { policydb_destroy(&policydb); avtab_cache_destroy(); - return rc; + goto out; } security_load_policycaps(); @@ -1874,36 +1881,36 @@ int security_load_policy(void *data, size_t len) selinux_status_update_policyload(seqno); selinux_netlbl_cache_invalidate(); selinux_xfrm_notify_policyload(); - return 0; + goto out; } #if 0 sidtab_hash_eval(&sidtab, "sids"); #endif - rc = policydb_read(&newpolicydb, fp); + rc = policydb_read(newpolicydb, fp); if (rc) - return rc; + goto out; - newpolicydb.len = len; + newpolicydb->len = len; /* If switching between different policy types, log MLS status */ - if (policydb.mls_enabled && !newpolicydb.mls_enabled) + if (policydb.mls_enabled && !newpolicydb->mls_enabled) printk(KERN_INFO "SELinux: Disabling MLS support...\n"); - else if (!policydb.mls_enabled && newpolicydb.mls_enabled) + else if (!policydb.mls_enabled && newpolicydb->mls_enabled) printk(KERN_INFO "SELinux: Enabling MLS support...\n"); - rc = policydb_load_isids(&newpolicydb, &newsidtab); + rc = policydb_load_isids(newpolicydb, &newsidtab); if (rc) { printk(KERN_ERR "SELinux: unable to load the initial SIDs\n"); - policydb_destroy(&newpolicydb); - return rc; + policydb_destroy(newpolicydb); + goto out; } - rc = selinux_set_mapping(&newpolicydb, secclass_map, &map, &map_size); + rc = selinux_set_mapping(newpolicydb, secclass_map, &map, &map_size); if (rc) goto err; - rc = security_preserve_bools(&newpolicydb); + rc = security_preserve_bools(newpolicydb); if (rc) { printk(KERN_ERR "SELinux: unable to preserve booleans\n"); goto err; @@ -1921,7 +1928,7 @@ int security_load_policy(void *data, size_t len) * in the new SID table. */ args.oldp = &policydb; - args.newp = &newpolicydb; + args.newp = newpolicydb; rc = sidtab_map(&newsidtab, convert_context, &args); if (rc) { printk(KERN_ERR "SELinux: unable to convert the internal" @@ -1931,12 +1938,12 @@ int security_load_policy(void *data, size_t len) } /* Save the old policydb and SID table to free later. */ - memcpy(&oldpolicydb, &policydb, sizeof policydb); + memcpy(oldpolicydb, &policydb, sizeof(policydb)); sidtab_set(&oldsidtab, &sidtab); /* Install the new policydb and SID table. */ write_lock_irq(&policy_rwlock); - memcpy(&policydb, &newpolicydb, sizeof policydb); + memcpy(&policydb, newpolicydb, sizeof(policydb)); sidtab_set(&sidtab, &newsidtab); security_load_policycaps(); oldmap = current_mapping; @@ -1946,7 +1953,7 @@ int security_load_policy(void *data, size_t len) write_unlock_irq(&policy_rwlock); /* Free the old policydb and SID table. */ - policydb_destroy(&oldpolicydb); + policydb_destroy(oldpolicydb); sidtab_destroy(&oldsidtab); kfree(oldmap); @@ -1956,14 +1963,17 @@ int security_load_policy(void *data, size_t len) selinux_netlbl_cache_invalidate(); selinux_xfrm_notify_policyload(); - return 0; + rc = 0; + goto out; err: kfree(map); sidtab_destroy(&newsidtab); - policydb_destroy(&newpolicydb); - return rc; + policydb_destroy(newpolicydb); +out: + kfree(oldpolicydb); + return rc; } size_t security_policydb_len(void) From 8e645c345a4cf6b8b13054b4ec2f6371f05876a9 Mon Sep 17 00:00:00 2001 From: "Geyslan G. Bem" Date: Sun, 24 Nov 2013 08:37:01 -0300 Subject: [PATCH 03/13] selinux: fix possible memory leak Free 'ctx_str' when necessary. Signed-off-by: Geyslan G. Bem Cc: stable@vger.kernel.org Signed-off-by: Paul Moore --- security/selinux/xfrm.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c index a91d205ec0c6..cf79a4564e38 100644 --- a/security/selinux/xfrm.c +++ b/security/selinux/xfrm.c @@ -327,19 +327,22 @@ int selinux_xfrm_state_alloc_acquire(struct xfrm_state *x, return rc; ctx = kmalloc(sizeof(*ctx) + str_len, GFP_ATOMIC); - if (!ctx) - return -ENOMEM; + if (!ctx) { + rc = -ENOMEM; + goto out; + } ctx->ctx_doi = XFRM_SC_DOI_LSM; ctx->ctx_alg = XFRM_SC_ALG_SELINUX; ctx->ctx_sid = secid; ctx->ctx_len = str_len; memcpy(ctx->ctx_str, ctx_str, str_len); - kfree(ctx_str); x->security = ctx; atomic_inc(&selinux_xfrm_refcount); - return 0; +out: + kfree(ctx_str); + return rc; } /* From da2ea0d05671f878196cc949906aa89d15c567db Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Tue, 3 Dec 2013 11:14:04 -0500 Subject: [PATCH 04/13] selinux: handle TCP SYN-ACK packets correctly in selinux_ip_output() In selinux_ip_output() we always label packets based on the parent socket. While this approach works in almost all cases, it doesn't work in the case of TCP SYN-ACK packets when the correct label is not the label of the parent socket, but rather the label of the larval socket represented by the request_sock struct. Unfortunately, since the request_sock isn't queued on the parent socket until *after* the SYN-ACK packet is sent, we can't lookup the request_sock to determine the correct label for the packet; at this point in time the best we can do is simply pass/NF_ACCEPT the packet. It must be said that simply passing the packet without any explicit labeling action, while far from ideal, is not terrible as the SYN-ACK packet will inherit any IP option based labeling from the initial connection request so the label *should* be correct and all our access controls remain in place so we shouldn't have to worry about information leaks. Reported-by: Janak Desai Tested-by: Janak Desai Cc: stable@vger.kernel.org Signed-off-by: Paul Moore --- security/selinux/hooks.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 777ee98273d1..877bab748c87 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -53,6 +53,7 @@ #include /* for local_port_range[] */ #include #include /* struct or_callable used in sock_rcv_skb */ +#include #include #include #include @@ -4731,6 +4732,7 @@ static unsigned int selinux_ipv6_forward(unsigned int hooknum, static unsigned int selinux_ip_output(struct sk_buff *skb, u16 family) { + struct sock *sk; u32 sid; if (!netlbl_enabled()) @@ -4739,8 +4741,27 @@ static unsigned int selinux_ip_output(struct sk_buff *skb, /* we do this in the LOCAL_OUT path and not the POST_ROUTING path * because we want to make sure we apply the necessary labeling * before IPsec is applied so we can leverage AH protection */ - if (skb->sk) { - struct sk_security_struct *sksec = skb->sk->sk_security; + sk = skb->sk; + if (sk) { + struct sk_security_struct *sksec; + + if (sk->sk_state == TCP_LISTEN) + /* if the socket is the listening state then this + * packet is a SYN-ACK packet which means it needs to + * be labeled based on the connection/request_sock and + * not the parent socket. unfortunately, we can't + * lookup the request_sock yet as it isn't queued on + * the parent socket until after the SYN-ACK is sent. + * the "solution" is to simply pass the packet as-is + * as any IP option based labeling should be copied + * from the initial connection request (in the IP + * layer). it is far from ideal, but until we get a + * security label in the packet itself this is the + * best we can do. */ + return NF_ACCEPT; + + /* standard practice, label using the parent socket */ + sksec = sk->sk_security; sid = sksec->sid; } else sid = SECINITSID_KERNEL; From 7f721643db3b2da53e1b91aaa4e8cb7706bfdd10 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Tue, 3 Dec 2013 11:16:36 -0500 Subject: [PATCH 05/13] selinux: handle TCP SYN-ACK packets correctly in selinux_ip_postroute() In selinux_ip_postroute() we perform access checks based on the packet's security label. For locally generated traffic we get the packet's security label from the associated socket; this works in all cases except for TCP SYN-ACK packets. In the case of SYN-ACK packet's the correct security label is stored in the connection's request_sock, not the server's socket. Unfortunately, at the point in time when selinux_ip_postroute() is called we can't query the request_sock directly, we need to recreate the label using the same logic that originally labeled the associated request_sock. See the inline comments for more explanation. Reported-by: Janak Desai Tested-by: Janak Desai Cc: stable@vger.kernel.org Signed-off-by: Paul Moore --- security/selinux/hooks.c | 68 +++++++++++++++++++++++++++++++--------- 1 file changed, 53 insertions(+), 15 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 877bab748c87..cc076a9b0344 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3847,6 +3847,30 @@ static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid) return 0; } +/** + * selinux_conn_sid - Determine the child socket label for a connection + * @sk_sid: the parent socket's SID + * @skb_sid: the packet's SID + * @conn_sid: the resulting connection SID + * + * If @skb_sid is valid then the user:role:type information from @sk_sid is + * combined with the MLS information from @skb_sid in order to create + * @conn_sid. If @skb_sid is not valid then then @conn_sid is simply a copy + * of @sk_sid. Returns zero on success, negative values on failure. + * + */ +static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid) +{ + int err = 0; + + if (skb_sid != SECSID_NULL) + err = security_sid_mls_copy(sk_sid, skb_sid, conn_sid); + else + *conn_sid = sk_sid; + + return err; +} + /* socket security operations */ static int socket_sockcreate_sid(const struct task_security_struct *tsec, @@ -4453,7 +4477,7 @@ static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, struct sk_security_struct *sksec = sk->sk_security; int err; u16 family = sk->sk_family; - u32 newsid; + u32 connsid; u32 peersid; /* handle mapped IPv4 packets arriving via IPv6 sockets */ @@ -4463,16 +4487,11 @@ static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, err = selinux_skb_peerlbl_sid(skb, family, &peersid); if (err) return err; - if (peersid == SECSID_NULL) { - req->secid = sksec->sid; - req->peer_secid = SECSID_NULL; - } else { - err = security_sid_mls_copy(sksec->sid, peersid, &newsid); - if (err) - return err; - req->secid = newsid; - req->peer_secid = peersid; - } + err = selinux_conn_sid(sksec->sid, peersid, &connsid); + if (err) + return err; + req->secid = connsid; + req->peer_secid = peersid; return selinux_netlbl_inet_conn_request(req, family); } @@ -4846,12 +4865,12 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, if (!secmark_active && !peerlbl_active) return NF_ACCEPT; - /* if the packet is being forwarded then get the peer label from the - * packet itself; otherwise check to see if it is from a local - * application or the kernel, if from an application get the peer label - * from the sending socket, otherwise use the kernel's sid */ sk = skb->sk; if (sk == NULL) { + /* Without an associated socket the packet is either coming + * from the kernel or it is being forwarded; check the packet + * to determine which and if the packet is being forwarded + * query the packet directly to determine the security label. */ if (skb->skb_iif) { secmark_perm = PACKET__FORWARD_OUT; if (selinux_skb_peerlbl_sid(skb, family, &peer_sid)) @@ -4860,7 +4879,26 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, secmark_perm = PACKET__SEND; peer_sid = SECINITSID_KERNEL; } + } else if (sk->sk_state == TCP_LISTEN) { + /* Locally generated packet but the associated socket is in the + * listening state which means this is a SYN-ACK packet. In + * this particular case the correct security label is assigned + * to the connection/request_sock but unfortunately we can't + * query the request_sock as it isn't queued on the parent + * socket until after the SYN-ACK packet is sent; the only + * viable choice is to regenerate the label like we do in + * selinux_inet_conn_request(). See also selinux_ip_output() + * for similar problems. */ + u32 skb_sid; + struct sk_security_struct *sksec = sk->sk_security; + if (selinux_skb_peerlbl_sid(skb, family, &skb_sid)) + return NF_DROP; + if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid)) + return NF_DROP; + secmark_perm = PACKET__SEND; } else { + /* Locally generated packet, fetch the security label from the + * associated socket. */ struct sk_security_struct *sksec = sk->sk_security; peer_sid = sksec->sid; secmark_perm = PACKET__SEND; From 050d032b25e617cd738db8d6fd5aed24d87cbbcb Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Tue, 3 Dec 2013 11:36:11 -0500 Subject: [PATCH 06/13] selinux: ensure that the cached NetLabel secattr matches the desired SID In selinux_netlbl_skbuff_setsid() we leverage a cached NetLabel secattr whenever possible. However, we never check to ensure that the desired SID matches the cached NetLabel secattr. This patch checks the SID against the secattr before use and only uses the cached secattr when the SID values match. Signed-off-by: Paul Moore --- security/selinux/netlabel.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c index 6235d052338b..0364120d1ec8 100644 --- a/security/selinux/netlabel.c +++ b/security/selinux/netlabel.c @@ -100,6 +100,32 @@ static struct netlbl_lsm_secattr *selinux_netlbl_sock_genattr(struct sock *sk) return secattr; } +/** + * selinux_netlbl_sock_getattr - Get the cached NetLabel secattr + * @sk: the socket + * @sid: the SID + * + * Query the socket's cached secattr and if the SID matches the cached value + * return the cache, otherwise return NULL. + * + */ +static struct netlbl_lsm_secattr *selinux_netlbl_sock_getattr( + const struct sock *sk, + u32 sid) +{ + struct sk_security_struct *sksec = sk->sk_security; + struct netlbl_lsm_secattr *secattr = sksec->nlbl_secattr; + + if (secattr == NULL) + return NULL; + + if ((secattr->flags & NETLBL_SECATTR_SECID) && + (secattr->attr.secid == sid)) + return secattr; + + return NULL; +} + /** * selinux_netlbl_cache_invalidate - Invalidate the NetLabel cache * @@ -224,7 +250,7 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb, struct sk_security_struct *sksec = sk->sk_security; if (sksec->nlbl_state != NLBL_REQSKB) return 0; - secattr = sksec->nlbl_secattr; + secattr = selinux_netlbl_sock_getattr(sk, sid); } if (secattr == NULL) { secattr = &secattr_storage; @@ -410,6 +436,9 @@ int selinux_netlbl_socket_setsockopt(struct socket *sock, sksec->nlbl_state == NLBL_CONNLABELED)) { netlbl_secattr_init(&secattr); lock_sock(sk); + /* call the netlabel function directly as we want to see the + * on-the-wire label that is assigned via the socket's options + * and not the cached netlabel/lsm attributes */ rc = netlbl_sock_getattr(sk, &secattr); release_sock(sk); if (rc == 0) From 0b1f24e6db9a60c1f68117ad158ea29faa7c3a7f Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Tue, 3 Dec 2013 11:39:13 -0500 Subject: [PATCH 07/13] selinux: pull address family directly from the request_sock struct We don't need to inspect the packet to determine if the packet is an IPv4 packet arriving on an IPv6 socket when we can query the request_sock directly. Signed-off-by: Paul Moore --- security/selinux/hooks.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index cc076a9b0344..17d7689660ea 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4476,14 +4476,10 @@ static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, { struct sk_security_struct *sksec = sk->sk_security; int err; - u16 family = sk->sk_family; + u16 family = req->rsk_ops->family; u32 connsid; u32 peersid; - /* handle mapped IPv4 packets arriving via IPv6 sockets */ - if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) - family = PF_INET; - err = selinux_skb_peerlbl_sid(skb, family, &peersid); if (err) return err; From 5b67c493248059909d7e0ff646d8475306669b27 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Mon, 9 Dec 2013 15:32:33 -0500 Subject: [PATCH 08/13] selinux: look for IPsec labels on both inbound and outbound packets Previously selinux_skb_peerlbl_sid() would only check for labeled IPsec security labels on inbound packets, this patch enables it to check both inbound and outbound traffic for labeled IPsec security labels. Reported-by: Janak Desai Cc: stable@vger.kernel.org Signed-off-by: Paul Moore --- security/selinux/hooks.c | 2 +- security/selinux/include/xfrm.h | 12 ++++---- security/selinux/xfrm.c | 51 ++++++++++++++++++++++++++------- 3 files changed, 49 insertions(+), 16 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 17d7689660ea..95cb1345257d 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3829,7 +3829,7 @@ static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid) u32 nlbl_sid; u32 nlbl_type; - err = selinux_skb_xfrm_sid(skb, &xfrm_sid); + err = selinux_xfrm_skb_sid(skb, &xfrm_sid); if (unlikely(err)) return -EACCES; err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid); diff --git a/security/selinux/include/xfrm.h b/security/selinux/include/xfrm.h index 0dec76c64cf5..48c3cc94c168 100644 --- a/security/selinux/include/xfrm.h +++ b/security/selinux/include/xfrm.h @@ -39,6 +39,7 @@ int selinux_xfrm_sock_rcv_skb(u32 sk_sid, struct sk_buff *skb, int selinux_xfrm_postroute_last(u32 sk_sid, struct sk_buff *skb, struct common_audit_data *ad, u8 proto); int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall); +int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid); static inline void selinux_xfrm_notify_policyload(void) { @@ -79,11 +80,12 @@ static inline int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, static inline void selinux_xfrm_notify_policyload(void) { } + +static inline int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid) +{ + *sid = SECSID_NULL; + return 0; +} #endif -static inline int selinux_skb_xfrm_sid(struct sk_buff *skb, u32 *sid) -{ - return selinux_xfrm_decode_session(skb, sid, 0); -} - #endif /* _SELINUX_XFRM_H_ */ diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c index cf79a4564e38..0462cb3ff0a7 100644 --- a/security/selinux/xfrm.c +++ b/security/selinux/xfrm.c @@ -209,19 +209,26 @@ int selinux_xfrm_state_pol_flow_match(struct xfrm_state *x, NULL) ? 0 : 1); } -/* - * LSM hook implementation that checks and/or returns the xfrm sid for the - * incoming packet. - */ -int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall) +static u32 selinux_xfrm_skb_sid_egress(struct sk_buff *skb) +{ + struct dst_entry *dst = skb_dst(skb); + struct xfrm_state *x; + + if (dst == NULL) + return SECSID_NULL; + x = dst->xfrm; + if (x == NULL || !selinux_authorizable_xfrm(x)) + return SECSID_NULL; + + return x->security->ctx_sid; +} + +static int selinux_xfrm_skb_sid_ingress(struct sk_buff *skb, + u32 *sid, int ckall) { u32 sid_session = SECSID_NULL; - struct sec_path *sp; + struct sec_path *sp = skb->sp; - if (skb == NULL) - goto out; - - sp = skb->sp; if (sp) { int i; @@ -247,6 +254,30 @@ out: return 0; } +/* + * LSM hook implementation that checks and/or returns the xfrm sid for the + * incoming packet. + */ +int selinux_xfrm_decode_session(struct sk_buff *skb, u32 *sid, int ckall) +{ + if (skb == NULL) { + *sid = SECSID_NULL; + return 0; + } + return selinux_xfrm_skb_sid_ingress(skb, sid, ckall); +} + +int selinux_xfrm_skb_sid(struct sk_buff *skb, u32 *sid) +{ + int rc; + + rc = selinux_xfrm_skb_sid_ingress(skb, sid, 0); + if (rc == 0 && *sid == SECSID_NULL) + *sid = selinux_xfrm_skb_sid_egress(skb); + + return rc; +} + /* * LSM hook implementation that allocs and transfers uctx spec to xfrm_policy. */ From 5c6c26813a209e7075baf908e3ad81c1a9d389e8 Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Mon, 9 Dec 2013 16:11:53 -0500 Subject: [PATCH 09/13] selinux: process labeled IPsec TCP SYN-ACK packets properly in selinux_ip_postroute() Due to difficulty in arriving at the proper security label for TCP SYN-ACK packets in selinux_ip_postroute(), we need to check packets while/before they are undergoing XFRM transforms instead of waiting until afterwards so that we can determine the correct security label. Reported-by: Janak Desai Cc: stable@vger.kernel.org Signed-off-by: Paul Moore --- security/selinux/hooks.c | 48 +++++++++++++++++++++++++++++++--------- 1 file changed, 38 insertions(+), 10 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 95cb1345257d..a98228e7b91d 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4846,22 +4846,31 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, * as fast and as clean as possible. */ if (!selinux_policycap_netpeer) return selinux_ip_postroute_compat(skb, ifindex, family); -#ifdef CONFIG_XFRM - /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec - * packet transformation so allow the packet to pass without any checks - * since we'll have another chance to perform access control checks - * when the packet is on it's final way out. - * NOTE: there appear to be some IPv6 multicast cases where skb->dst - * is NULL, in this case go ahead and apply access control. */ - if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL) - return NF_ACCEPT; -#endif + secmark_active = selinux_secmark_enabled(); peerlbl_active = selinux_peerlbl_enabled(); if (!secmark_active && !peerlbl_active) return NF_ACCEPT; sk = skb->sk; + +#ifdef CONFIG_XFRM + /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec + * packet transformation so allow the packet to pass without any checks + * since we'll have another chance to perform access control checks + * when the packet is on it's final way out. + * NOTE: there appear to be some IPv6 multicast cases where skb->dst + * is NULL, in this case go ahead and apply access control. + * NOTE: if this is a local socket (skb->sk != NULL) that is in the + * TCP listening state we cannot wait until the XFRM processing + * is done as we will miss out on the SA label if we do; + * unfortunately, this means more work, but it is only once per + * connection. */ + if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL && + !(sk != NULL && sk->sk_state == TCP_LISTEN)) + return NF_ACCEPT; +#endif + if (sk == NULL) { /* Without an associated socket the packet is either coming * from the kernel or it is being forwarded; check the packet @@ -4889,6 +4898,25 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, struct sk_security_struct *sksec = sk->sk_security; if (selinux_skb_peerlbl_sid(skb, family, &skb_sid)) return NF_DROP; + /* At this point, if the returned skb peerlbl is SECSID_NULL + * and the packet has been through at least one XFRM + * transformation then we must be dealing with the "final" + * form of labeled IPsec packet; since we've already applied + * all of our access controls on this packet we can safely + * pass the packet. */ + if (skb_sid == SECSID_NULL) { + switch (family) { + case PF_INET: + if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) + return NF_ACCEPT; + break; + case PF_INET6: + if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) + return NF_ACCEPT; + default: + return NF_DROP_ERR(-ECONNREFUSED); + } + } if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid)) return NF_DROP; secmark_perm = PACKET__SEND; From 598cdbcf861825692fe7905e0fd662c7d06bae58 Mon Sep 17 00:00:00 2001 From: Chad Hanson Date: Wed, 11 Dec 2013 17:07:56 -0500 Subject: [PATCH 10/13] selinux: fix broken peer recv check Fix a broken networking check. Return an error if peer recv fails. If secmark is active and the packet recv succeeds the peer recv error is ignored. Signed-off-by: Chad Hanson Signed-off-by: Paul Moore --- security/selinux/hooks.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index a98228e7b91d..bf0537d78a70 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4338,8 +4338,10 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) } err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER, PEER__RECV, &ad); - if (err) + if (err) { selinux_netlbl_err(skb, err, 0); + return err; + } } if (secmark_active) { From 4d546f81717d253ab67643bf072c6d8821a9249c Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Fri, 13 Dec 2013 14:49:53 -0500 Subject: [PATCH 11/13] selinux: revert 102aefdda4d8275ce7d7100bc16c88c74272b260 Revert "selinux: consider filesystem subtype in policies" This reverts commit 102aefdda4d8275ce7d7100bc16c88c74272b260. Explanation from Eric Paris: SELinux policy can specify if it should use a filesystem's xattrs or not. In current policy we have a specification that fuse should not use xattrs but fuse.glusterfs should use xattrs. This patch has a bug in which non-glusterfs filesystems would match the rule saying fuse.glusterfs should use xattrs. If both fuse and the particular filesystem in question are not written to handle xattr calls during the mount command, they will deadlock. I have fixed the bug to do proper matching, however I believe a revert is still the correct solution. The reason I believe that is because the code still does not work. The s_subtype is not set until after the SELinux hook which attempts to match on the ".gluster" portion of the rule. So we cannot match on the rule in question. The code is useless. Signed-off-by: Paul Moore --- security/selinux/hooks.c | 40 +++++++++++++++----------------- security/selinux/ss/services.c | 42 ++++------------------------------ 2 files changed, 22 insertions(+), 60 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index bf0537d78a70..756a6d269c9a 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -96,10 +96,6 @@ #include "audit.h" #include "avc_ss.h" -#define SB_TYPE_FMT "%s%s%s" -#define SB_SUBTYPE(sb) (sb->s_subtype && sb->s_subtype[0]) -#define SB_TYPE_ARGS(sb) sb->s_type->name, SB_SUBTYPE(sb) ? "." : "", SB_SUBTYPE(sb) ? sb->s_subtype : "" - extern struct security_operations *security_ops; /* SECMARK reference count */ @@ -414,8 +410,8 @@ static int sb_finish_set_opts(struct super_block *sb) the first boot of the SELinux kernel before we have assigned xattr values to the filesystem. */ if (!root_inode->i_op->getxattr) { - printk(KERN_WARNING "SELinux: (dev %s, type "SB_TYPE_FMT") has no " - "xattr support\n", sb->s_id, SB_TYPE_ARGS(sb)); + printk(KERN_WARNING "SELinux: (dev %s, type %s) has no " + "xattr support\n", sb->s_id, sb->s_type->name); rc = -EOPNOTSUPP; goto out; } @@ -423,22 +419,22 @@ static int sb_finish_set_opts(struct super_block *sb) if (rc < 0 && rc != -ENODATA) { if (rc == -EOPNOTSUPP) printk(KERN_WARNING "SELinux: (dev %s, type " - SB_TYPE_FMT") has no security xattr handler\n", - sb->s_id, SB_TYPE_ARGS(sb)); + "%s) has no security xattr handler\n", + sb->s_id, sb->s_type->name); else printk(KERN_WARNING "SELinux: (dev %s, type " - SB_TYPE_FMT") getxattr errno %d\n", sb->s_id, - SB_TYPE_ARGS(sb), -rc); + "%s) getxattr errno %d\n", sb->s_id, + sb->s_type->name, -rc); goto out; } } if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) - printk(KERN_ERR "SELinux: initialized (dev %s, type "SB_TYPE_FMT"), unknown behavior\n", - sb->s_id, SB_TYPE_ARGS(sb)); + printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n", + sb->s_id, sb->s_type->name); else - printk(KERN_DEBUG "SELinux: initialized (dev %s, type "SB_TYPE_FMT"), %s\n", - sb->s_id, SB_TYPE_ARGS(sb), + printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n", + sb->s_id, sb->s_type->name, labeling_behaviors[sbsec->behavior-1]); sbsec->flags |= SE_SBINITIALIZED; @@ -601,6 +597,7 @@ static int selinux_set_mnt_opts(struct super_block *sb, const struct cred *cred = current_cred(); int rc = 0, i; struct superblock_security_struct *sbsec = sb->s_security; + const char *name = sb->s_type->name; struct inode *inode = sbsec->sb->s_root->d_inode; struct inode_security_struct *root_isec = inode->i_security; u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; @@ -659,8 +656,8 @@ static int selinux_set_mnt_opts(struct super_block *sb, strlen(mount_options[i]), &sid); if (rc) { printk(KERN_WARNING "SELinux: security_context_to_sid" - "(%s) failed for (dev %s, type "SB_TYPE_FMT") errno=%d\n", - mount_options[i], sb->s_id, SB_TYPE_ARGS(sb), rc); + "(%s) failed for (dev %s, type %s) errno=%d\n", + mount_options[i], sb->s_id, name, rc); goto out; } switch (flags[i]) { @@ -807,8 +804,7 @@ out: out_double_mount: rc = -EINVAL; printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different " - "security settings for (dev %s, type "SB_TYPE_FMT")\n", sb->s_id, - SB_TYPE_ARGS(sb)); + "security settings for (dev %s, type %s)\n", sb->s_id, name); goto out; } @@ -2481,8 +2477,8 @@ static int selinux_sb_remount(struct super_block *sb, void *data) rc = security_context_to_sid(mount_options[i], len, &sid); if (rc) { printk(KERN_WARNING "SELinux: security_context_to_sid" - "(%s) failed for (dev %s, type "SB_TYPE_FMT") errno=%d\n", - mount_options[i], sb->s_id, SB_TYPE_ARGS(sb), rc); + "(%s) failed for (dev %s, type %s) errno=%d\n", + mount_options[i], sb->s_id, sb->s_type->name, rc); goto out_free_opts; } rc = -EINVAL; @@ -2520,8 +2516,8 @@ out_free_secdata: return rc; out_bad_option: printk(KERN_WARNING "SELinux: unable to change security options " - "during remount (dev %s, type "SB_TYPE_FMT")\n", sb->s_id, - SB_TYPE_ARGS(sb)); + "during remount (dev %s, type=%s)\n", sb->s_id, + sb->s_type->name); goto out_free_opts; } diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 6db5546717eb..fc5a63a05a1c 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -2344,50 +2344,16 @@ int security_fs_use(struct super_block *sb) struct ocontext *c; struct superblock_security_struct *sbsec = sb->s_security; const char *fstype = sb->s_type->name; - const char *subtype = (sb->s_subtype && sb->s_subtype[0]) ? sb->s_subtype : NULL; - struct ocontext *base = NULL; read_lock(&policy_rwlock); - for (c = policydb.ocontexts[OCON_FSUSE]; c; c = c->next) { - char *sub; - int baselen; - - baselen = strlen(fstype); - - /* if base does not match, this is not the one */ - if (strncmp(fstype, c->u.name, baselen)) - continue; - - /* if there is no subtype, this is the one! */ - if (!subtype) - break; - - /* skip past the base in this entry */ - sub = c->u.name + baselen; - - /* entry is only a base. save it. keep looking for subtype */ - if (sub[0] == '\0') { - base = c; - continue; - } - - /* entry is not followed by a subtype, so it is not a match */ - if (sub[0] != '.') - continue; - - /* whew, we found a subtype of this fstype */ - sub++; /* move past '.' */ - - /* exact match of fstype AND subtype */ - if (!strcmp(subtype, sub)) + c = policydb.ocontexts[OCON_FSUSE]; + while (c) { + if (strcmp(fstype, c->u.name) == 0) break; + c = c->next; } - /* in case we had found an fstype match but no subtype match */ - if (!c) - c = base; - if (c) { sbsec->behavior = c->v.behavior; if (!c->sid[0]) { From a5e333d34037c64c5f667dee3c418b66874ba0b0 Mon Sep 17 00:00:00 2001 From: Wei Yongjun Date: Mon, 16 Dec 2013 14:15:40 +0800 Subject: [PATCH 12/13] SELinux: remove duplicated include from hooks.c Remove duplicated include. Signed-off-by: Wei Yongjun Signed-off-by: Paul Moore --- security/selinux/hooks.c | 1 - 1 file changed, 1 deletion(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 756a6d269c9a..ded2d47e5ee1 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -82,7 +82,6 @@ #include #include #include -#include #include #include From 465954cd649a7d8cd331695bd24a16bcb5c4c716 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Sat, 14 Dec 2013 17:33:17 +0100 Subject: [PATCH 13/13] selinux: selinux_setprocattr()->ptrace_parent() needs rcu_read_lock() selinux_setprocattr() does ptrace_parent(p) under task_lock(p), but task_struct->alloc_lock doesn't pin ->parent or ->ptrace, this looks confusing and triggers the "suspicious RCU usage" warning because ptrace_parent() does rcu_dereference_check(). And in theory this is wrong, spin_lock()->preempt_disable() doesn't necessarily imply rcu_read_lock() we need to access the ->parent. Reported-by: Evan McNabb Signed-off-by: Oleg Nesterov Cc: stable@vger.kernel.org Signed-off-by: Paul Moore --- security/selinux/hooks.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index ded2d47e5ee1..6ace9b3abf0d 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -5583,11 +5583,11 @@ static int selinux_setprocattr(struct task_struct *p, /* Check for ptracing, and update the task SID if ok. Otherwise, leave SID unchanged and fail. */ ptsid = 0; - task_lock(p); + rcu_read_lock(); tracer = ptrace_parent(p); if (tracer) ptsid = task_sid(tracer); - task_unlock(p); + rcu_read_unlock(); if (tracer) { error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,