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-rw-r--r--security/selinux/avc.c95
-rw-r--r--security/selinux/hooks.c119
-rw-r--r--security/selinux/include/avc.h13
-rw-r--r--security/selinux/ss/policydb.c1
-rw-r--r--security/selinux/ss/services.c4
5 files changed, 138 insertions, 94 deletions
diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index ecd3829996aa..d18cb32a242a 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -424,7 +424,7 @@ static inline int avc_xperms_audit(struct selinux_state *state,
if (likely(!audited))
return 0;
return slow_avc_audit(state, ssid, tsid, tclass, requested,
- audited, denied, result, ad, 0);
+ audited, denied, result, ad);
}
static void avc_node_free(struct rcu_head *rhead)
@@ -617,40 +617,37 @@ static struct avc_node *avc_insert(struct selinux_avc *avc,
struct avc_node *pos, *node = NULL;
int hvalue;
unsigned long flag;
+ spinlock_t *lock;
+ struct hlist_head *head;
if (avc_latest_notif_update(avc, avd->seqno, 1))
- goto out;
+ return NULL;
node = avc_alloc_node(avc);
- if (node) {
- struct hlist_head *head;
- spinlock_t *lock;
- int rc = 0;
-
- hvalue = avc_hash(ssid, tsid, tclass);
- avc_node_populate(node, ssid, tsid, tclass, avd);
- rc = avc_xperms_populate(node, xp_node);
- if (rc) {
- kmem_cache_free(avc_node_cachep, node);
- return NULL;
- }
- head = &avc->avc_cache.slots[hvalue];
- lock = &avc->avc_cache.slots_lock[hvalue];
+ if (!node)
+ return NULL;
- spin_lock_irqsave(lock, flag);
- hlist_for_each_entry(pos, head, list) {
- if (pos->ae.ssid == ssid &&
- pos->ae.tsid == tsid &&
- pos->ae.tclass == tclass) {
- avc_node_replace(avc, node, pos);
- goto found;
- }
+ avc_node_populate(node, ssid, tsid, tclass, avd);
+ if (avc_xperms_populate(node, xp_node)) {
+ avc_node_kill(avc, node);
+ return NULL;
+ }
+
+ hvalue = avc_hash(ssid, tsid, tclass);
+ head = &avc->avc_cache.slots[hvalue];
+ lock = &avc->avc_cache.slots_lock[hvalue];
+ spin_lock_irqsave(lock, flag);
+ hlist_for_each_entry(pos, head, list) {
+ if (pos->ae.ssid == ssid &&
+ pos->ae.tsid == tsid &&
+ pos->ae.tclass == tclass) {
+ avc_node_replace(avc, node, pos);
+ goto found;
}
- hlist_add_head_rcu(&node->list, head);
-found:
- spin_unlock_irqrestore(lock, flag);
}
-out:
+ hlist_add_head_rcu(&node->list, head);
+found:
+ spin_unlock_irqrestore(lock, flag);
return node;
}
@@ -758,8 +755,7 @@ static void avc_audit_post_callback(struct audit_buffer *ab, void *a)
noinline int slow_avc_audit(struct selinux_state *state,
u32 ssid, u32 tsid, u16 tclass,
u32 requested, u32 audited, u32 denied, int result,
- struct common_audit_data *a,
- unsigned int flags)
+ struct common_audit_data *a)
{
struct common_audit_data stack_data;
struct selinux_audit_data sad;
@@ -772,17 +768,6 @@ noinline int slow_avc_audit(struct selinux_state *state,
a->type = LSM_AUDIT_DATA_NONE;
}
- /*
- * When in a RCU walk do the audit on the RCU retry. This is because
- * the collection of the dname in an inode audit message is not RCU
- * safe. Note this may drop some audits when the situation changes
- * during retry. However this is logically just as if the operation
- * happened a little later.
- */
- if ((a->type == LSM_AUDIT_DATA_INODE) &&
- (flags & MAY_NOT_BLOCK))
- return -ECHILD;
-
sad.tclass = tclass;
sad.requested = requested;
sad.ssid = ssid;
@@ -855,15 +840,14 @@ static int avc_update_node(struct selinux_avc *avc,
/*
* If we are in a non-blocking code path, e.g. VFS RCU walk,
* then we must not add permissions to a cache entry
- * because we cannot safely audit the denial. Otherwise,
+ * because we will not audit the denial. Otherwise,
* during the subsequent blocking retry (e.g. VFS ref walk), we
* will find the permissions already granted in the cache entry
* and won't audit anything at all, leading to silent denials in
* permissive mode that only appear when in enforcing mode.
*
- * See the corresponding handling in slow_avc_audit(), and the
- * logic in selinux_inode_permission for the MAY_NOT_BLOCK flag,
- * which is transliterated into AVC_NONBLOCKING.
+ * See the corresponding handling of MAY_NOT_BLOCK in avc_audit()
+ * and selinux_inode_permission().
*/
if (flags & AVC_NONBLOCKING)
return 0;
@@ -907,7 +891,7 @@ static int avc_update_node(struct selinux_avc *avc,
if (orig->ae.xp_node) {
rc = avc_xperms_populate(node, orig->ae.xp_node);
if (rc) {
- kmem_cache_free(avc_node_cachep, node);
+ avc_node_kill(avc, node);
goto out_unlock;
}
}
@@ -1205,6 +1189,25 @@ int avc_has_perm(struct selinux_state *state, u32 ssid, u32 tsid, u16 tclass,
return rc;
}
+int avc_has_perm_flags(struct selinux_state *state,
+ u32 ssid, u32 tsid, u16 tclass, u32 requested,
+ struct common_audit_data *auditdata,
+ int flags)
+{
+ struct av_decision avd;
+ int rc, rc2;
+
+ rc = avc_has_perm_noaudit(state, ssid, tsid, tclass, requested,
+ (flags & MAY_NOT_BLOCK) ? AVC_NONBLOCKING : 0,
+ &avd);
+
+ rc2 = avc_audit(state, ssid, tsid, tclass, requested, &avd, rc,
+ auditdata, flags);
+ if (rc2)
+ return rc2;
+ return rc;
+}
+
u32 avc_policy_seqno(struct selinux_state *state)
{
return state->avc->avc_cache.latest_notif;
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index c106167423a1..3cdc5a22004a 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2764,6 +2764,14 @@ static int selinux_mount(const char *dev_name,
return path_has_perm(cred, path, FILE__MOUNTON);
}
+static int selinux_move_mount(const struct path *from_path,
+ const struct path *to_path)
+{
+ const struct cred *cred = current_cred();
+
+ return path_has_perm(cred, to_path, FILE__MOUNTON);
+}
+
static int selinux_umount(struct vfsmount *mnt, int flags)
{
const struct cred *cred = current_cred();
@@ -3006,14 +3014,14 @@ static int selinux_inode_follow_link(struct dentry *dentry, struct inode *inode,
if (IS_ERR(isec))
return PTR_ERR(isec);
- return avc_has_perm(&selinux_state,
- sid, isec->sid, isec->sclass, FILE__READ, &ad);
+ return avc_has_perm_flags(&selinux_state,
+ sid, isec->sid, isec->sclass, FILE__READ, &ad,
+ rcu ? MAY_NOT_BLOCK : 0);
}
static noinline int audit_inode_permission(struct inode *inode,
u32 perms, u32 audited, u32 denied,
- int result,
- unsigned flags)
+ int result)
{
struct common_audit_data ad;
struct inode_security_struct *isec = selinux_inode(inode);
@@ -3024,7 +3032,7 @@ static noinline int audit_inode_permission(struct inode *inode,
rc = slow_avc_audit(&selinux_state,
current_sid(), isec->sid, isec->sclass, perms,
- audited, denied, result, &ad, flags);
+ audited, denied, result, &ad);
if (rc)
return rc;
return 0;
@@ -3071,7 +3079,11 @@ static int selinux_inode_permission(struct inode *inode, int mask)
if (likely(!audited))
return rc;
- rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags);
+ /* fall back to ref-walk if we have to generate audit */
+ if (flags & MAY_NOT_BLOCK)
+ return -ECHILD;
+
+ rc2 = audit_inode_permission(inode, perms, audited, denied, rc);
if (rc2)
return rc2;
return rc;
@@ -5461,44 +5473,6 @@ static int selinux_tun_dev_open(void *security)
return 0;
}
-static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
-{
- int err = 0;
- u32 perm;
- struct nlmsghdr *nlh;
- struct sk_security_struct *sksec = sk->sk_security;
-
- if (skb->len < NLMSG_HDRLEN) {
- err = -EINVAL;
- goto out;
- }
- nlh = nlmsg_hdr(skb);
-
- err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
- if (err) {
- if (err == -EINVAL) {
- pr_warn_ratelimited("SELinux: unrecognized netlink"
- " message: protocol=%hu nlmsg_type=%hu sclass=%s"
- " pig=%d comm=%s\n",
- sk->sk_protocol, nlh->nlmsg_type,
- secclass_map[sksec->sclass - 1].name,
- task_pid_nr(current), current->comm);
- if (!enforcing_enabled(&selinux_state) ||
- security_get_allow_unknown(&selinux_state))
- err = 0;
- }
-
- /* Ignore */
- if (err == -ENOENT)
- err = 0;
- goto out;
- }
-
- err = sock_has_perm(sk, perm);
-out:
- return err;
-}
-
#ifdef CONFIG_NETFILTER
static unsigned int selinux_ip_forward(struct sk_buff *skb,
@@ -5827,7 +5801,60 @@ static unsigned int selinux_ipv6_postroute(void *priv,
static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
{
- return selinux_nlmsg_perm(sk, skb);
+ int rc = 0;
+ unsigned int msg_len;
+ unsigned int data_len = skb->len;
+ unsigned char *data = skb->data;
+ struct nlmsghdr *nlh;
+ struct sk_security_struct *sksec = sk->sk_security;
+ u16 sclass = sksec->sclass;
+ u32 perm;
+
+ while (data_len >= nlmsg_total_size(0)) {
+ nlh = (struct nlmsghdr *)data;
+
+ /* NOTE: the nlmsg_len field isn't reliably set by some netlink
+ * users which means we can't reject skb's with bogus
+ * length fields; our solution is to follow what
+ * netlink_rcv_skb() does and simply skip processing at
+ * messages with length fields that are clearly junk
+ */
+ if (nlh->nlmsg_len < NLMSG_HDRLEN || nlh->nlmsg_len > data_len)
+ return 0;
+
+ rc = selinux_nlmsg_lookup(sclass, nlh->nlmsg_type, &perm);
+ if (rc == 0) {
+ rc = sock_has_perm(sk, perm);
+ if (rc)
+ return rc;
+ } else if (rc == -EINVAL) {
+ /* -EINVAL is a missing msg/perm mapping */
+ pr_warn_ratelimited("SELinux: unrecognized netlink"
+ " message: protocol=%hu nlmsg_type=%hu sclass=%s"
+ " pid=%d comm=%s\n",
+ sk->sk_protocol, nlh->nlmsg_type,
+ secclass_map[sclass - 1].name,
+ task_pid_nr(current), current->comm);
+ if (enforcing_enabled(&selinux_state) &&
+ !security_get_allow_unknown(&selinux_state))
+ return rc;
+ rc = 0;
+ } else if (rc == -ENOENT) {
+ /* -ENOENT is a missing socket/class mapping, ignore */
+ rc = 0;
+ } else {
+ return rc;
+ }
+
+ /* move to the next message after applying netlink padding */
+ msg_len = NLMSG_ALIGN(nlh->nlmsg_len);
+ if (msg_len >= data_len)
+ return 0;
+ data_len -= msg_len;
+ data += msg_len;
+ }
+
+ return rc;
}
static void ipc_init_security(struct ipc_security_struct *isec, u16 sclass)
@@ -6788,6 +6815,8 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
LSM_HOOK_INIT(sb_add_mnt_opt, selinux_add_mnt_opt),
+ LSM_HOOK_INIT(move_mount, selinux_move_mount),
+
LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security),
LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),
diff --git a/security/selinux/include/avc.h b/security/selinux/include/avc.h
index 7be0e1e90e8b..cf4cc3ef959b 100644
--- a/security/selinux/include/avc.h
+++ b/security/selinux/include/avc.h
@@ -100,8 +100,7 @@ static inline u32 avc_audit_required(u32 requested,
int slow_avc_audit(struct selinux_state *state,
u32 ssid, u32 tsid, u16 tclass,
u32 requested, u32 audited, u32 denied, int result,
- struct common_audit_data *a,
- unsigned flags);
+ struct common_audit_data *a);
/**
* avc_audit - Audit the granting or denial of permissions.
@@ -135,9 +134,12 @@ static inline int avc_audit(struct selinux_state *state,
audited = avc_audit_required(requested, avd, result, 0, &denied);
if (likely(!audited))
return 0;
+ /* fall back to ref-walk if we have to generate audit */
+ if (flags & MAY_NOT_BLOCK)
+ return -ECHILD;
return slow_avc_audit(state, ssid, tsid, tclass,
requested, audited, denied, result,
- a, flags);
+ a);
}
#define AVC_STRICT 1 /* Ignore permissive mode. */
@@ -153,6 +155,11 @@ int avc_has_perm(struct selinux_state *state,
u32 ssid, u32 tsid,
u16 tclass, u32 requested,
struct common_audit_data *auditdata);
+int avc_has_perm_flags(struct selinux_state *state,
+ u32 ssid, u32 tsid,
+ u16 tclass, u32 requested,
+ struct common_audit_data *auditdata,
+ int flags);
int avc_has_extended_perms(struct selinux_state *state,
u32 ssid, u32 tsid, u16 tclass, u32 requested,
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c
index f8efaa9f647c..23abad429668 100644
--- a/security/selinux/ss/policydb.c
+++ b/security/selinux/ss/policydb.c
@@ -2494,6 +2494,7 @@ int policydb_read(struct policydb *p, void *fp)
if (rc)
goto bad;
+ rc = -ENOMEM;
p->type_attr_map_array = kvcalloc(p->p_types.nprim,
sizeof(*p->type_attr_map_array),
GFP_KERNEL);
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 3585ef8c4836..e3cfbb182243 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -2845,8 +2845,12 @@ err:
if (*names) {
for (i = 0; i < *len; i++)
kfree((*names)[i]);
+ kfree(*names);
}
kfree(*values);
+ *len = 0;
+ *names = NULL;
+ *values = NULL;
goto out;
}
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-05-17 21:52:09 +0000