There are areas in the Labeled NFS code where where we need to test if the
attribute being requested exhibits the semantics of a MAC model. This allows us
to make sure that we get the desired semantics from the attribute instead of
something else such as capabilities or a time based LSM.
Signed-off-by: Matthew N. Dodd <Matthew.Dodd@xxxxxxxxxx>
Signed-off-by: David P. Quigley <dpquigl@xxxxxxxxxxxxx>
---
include/linux/security.h | 11 +++++++++++
security/security.c | 6 ++++++
security/selinux/hooks.c | 6 ++++++
security/smack/smack_lsm.c | 11 +++++++++++
4 files changed, 34 insertions(+), 0 deletions(-)
diff --git a/include/linux/security.h b/include/linux/security.h
index 42b9128..3031e6c 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -1244,6 +1244,10 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
* @pages contains the number of pages.
* Return 0 if permission is granted.
*
+ * @ismaclabel:
+ * Check if the extended attribute specified by @name represents a MAC label.
+ * @name full extended attribute name to check against LSM as a MAC label.
+ *
* @secid_to_secctx:
* Convert secid to security context.
* @secid contains the security ID.
@@ -1508,6 +1512,7 @@ struct security_operations {
int (*getprocattr) (struct task_struct *p, char *name, char **value);
int (*setprocattr) (struct task_struct *p, char *name, void *value, size_t size);
+ int (*ismaclabel) (const char * name);
int (*secid_to_secctx) (u32 secid, char **secdata, u32 *seclen);
int (*secctx_to_secid) (const char *secdata, u32 seclen, u32 *secid);
void (*release_secctx) (char *secdata, u32 seclen);
@@ -1762,6 +1767,7 @@ int security_getprocattr(struct task_struct *p, char *name, char **value);
int security_setprocattr(struct task_struct *p, char *name, void *value, size_t size);
int security_netlink_send(struct sock *sk, struct sk_buff *skb);
int security_netlink_recv(struct sk_buff *skb, int cap);
+int security_ismaclabel(const char *name);
int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen);
int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid);
void security_release_secctx(char *secdata, u32 seclen);
@@ -2494,6 +2500,11 @@ static inline void securityfs_remove(struct dentry *dentry)
{
}
+static inline int security_ismaclabel(const char *name)
+{
+ return 0;
+}
+
static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
{
return -EOPNOTSUPP;
diff --git a/security/security.c b/security/security.c
index b22a110..1955094 100644
--- a/security/security.c
+++ b/security/security.c
@@ -858,6 +858,12 @@ int security_netlink_recv(struct sk_buff *skb, int cap)
}
EXPORT_SYMBOL(security_netlink_recv);
+int security_ismaclabel(const char *name)
+{
+ return security_ops->ismaclabel(name);
+}
+EXPORT_SYMBOL(security_ismaclabel);
+
int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
{
return security_ops->secid_to_secctx(secid, secdata, seclen);
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 680db1d..248fa5c 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -5305,6 +5305,11 @@ static int selinux_setprocattr(struct task_struct *p,
return size;
}
+static int selinux_ismaclabel(const char *name)
+{
+ return (strcmp(name,XATTR_NAME_SELINUX) == 0);
+}
+
static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
{
return security_sid_to_context(secid, secdata, seclen);
@@ -5546,6 +5551,7 @@ static struct security_operations selinux_ops = {
.getprocattr = selinux_getprocattr,
.setprocattr = selinux_setprocattr,
+ .ismaclabel = selinux_ismaclabel,
.secid_to_secctx = selinux_secid_to_secctx,
.secctx_to_secid = selinux_secctx_to_secid,
.release_secctx = selinux_release_secctx,
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 87d7541..6b03a18 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -2526,6 +2526,16 @@ static void smack_audit_rule_free(void *vrule)
#endif /* CONFIG_AUDIT */
/*
+ * smack_ismaclabel - check if xattr @name references a smack MAC label
+ * @name: Full xattr name to check.
+ *
