smack: deduplicate xattr setting in smack_inode_init_security()

Signed-off-by: Konstantin Andreev <andreev@swemel.ru>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index d6f814aa15bae2170c98fe58c415009087a96baa..8609ae26e365ebbb139aa1842845c8569b075b1f 100644 (file)
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -980,6 +980,24 @@ smk_rule_transmutes(struct smack_known *subject,
        return (may > 0) && (may & MAY_TRANSMUTE);
 }
 
+static int
+xattr_dupval(struct xattr *xattrs, int *xattr_count,
+            const char *name, const void *value, unsigned int vallen)
+{
+       struct xattr * const xattr = lsm_get_xattr_slot(xattrs, xattr_count);
+
+       if (!xattr)
+               return 0;
+
+       xattr->value = kmemdup(value, vallen, GFP_NOFS);
+       if (!xattr->value)
+               return -ENOMEM;
+
+       xattr->value_len = vallen;
+       xattr->name = name;
+       return 0;
+}
+
 /**
  * smack_inode_init_security - copy out the smack from an inode
  * @inode: the newly created inode
@@ -997,7 +1015,6 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
        struct task_smack *tsp = smack_cred(current_cred());
        struct inode_smack * const issp = smack_inode(inode);
        struct smack_known *dsp = smk_of_inode(dir);
-       struct xattr *xattr = lsm_get_xattr_slot(xattrs, xattr_count);
        bool trans_cred;
        bool trans_rule;
 
@@ -1016,8 +1033,6 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
         * Mark the inode as changed.
         */
        if (trans_cred || (trans_rule && smk_inode_transmutable(dir))) {
-               struct xattr *xattr_transmute;
-
                /*
                 * The caller of smack_dentry_create_files_as()
                 * should have overridden the current cred, so the
@@ -1029,35 +1044,22 @@ static int smack_inode_init_security(struct inode *inode, struct inode *dir,
 
                if (S_ISDIR(inode->i_mode)) {
                        issp->smk_flags |= SMK_INODE_TRANSMUTE;
-                       xattr_transmute = lsm_get_xattr_slot(xattrs,
-                                                            xattr_count);
-                       if (xattr_transmute) {
-                               xattr_transmute->value = kmemdup(TRANS_TRUE,
-                                                                TRANS_TRUE_SIZE,
-                                                                GFP_NOFS);
-                               if (!xattr_transmute->value)
-                                       return -ENOMEM;
-
-                               xattr_transmute->value_len = TRANS_TRUE_SIZE;
-                               xattr_transmute->name = XATTR_SMACK_TRANSMUTE;
-                       }
+
+                       if (xattr_dupval(xattrs, xattr_count,
+                               XATTR_SMACK_TRANSMUTE,
+                               TRANS_TRUE,
+                               TRANS_TRUE_SIZE
+                       ))
+                               return -ENOMEM;
                }
        }
 
        issp->smk_flags |= SMK_INODE_INSTANT;
 
-       if (xattr) {
-               const char *inode_label = issp->smk_inode->smk_known;
-
-               xattr->value = kstrdup(inode_label, GFP_NOFS);
-               if (!xattr->value)
-                       return -ENOMEM;
-
-               xattr->value_len = strlen(inode_label);
-               xattr->name = XATTR_SMACK_SUFFIX;
-       }
-
-       return 0;
+       return xattr_dupval(xattrs, xattr_count,
+                           XATTR_SMACK_SUFFIX,
+                           issp->smk_inode->smk_known,
+                    strlen(issp->smk_inode->smk_known));
 }
 
 /**