Smack: setprocattr memory leak fix

The data structure allocations being done in prepare_creds
are duplicated in smack_setprocattr. This results in the
structure allocated in prepare_creds being orphaned and
never freed. The duplicate code is removed from
smack_setprocattr.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

security/smack/smack_lsm.c

@@ -2684,9 +2684,7 @@ static int smack_getprocattr(struct task_struct *p, char *name, char **value)
 static int smack_setprocattr(struct task_struct *p, char *name,
 			     void *value, size_t size)
 {
-	int rc;
 	struct task_smack *tsp;
-	struct task_smack *oldtsp;
 	struct cred *new;
 	char *newsmack;
 
@@ -2716,21 +2714,13 @@ static int smack_setprocattr(struct task_struct *p, char *name,
 	if (newsmack == smack_known_web.smk_known)
 		return -EPERM;
 
-	oldtsp = p->cred->security;
 	new = prepare_creds();
 	if (new == NULL)
 		return -ENOMEM;
 
-	tsp = new_task_smack(newsmack, oldtsp->smk_forked, GFP_KERNEL);
-	if (tsp == NULL) {
-		kfree(new);
-		return -ENOMEM;
-	}
-	rc = smk_copy_rules(&tsp->smk_rules, &oldtsp->smk_rules, GFP_KERNEL);
-	if (rc != 0)
-		return rc;
+	tsp = new->security;
+	tsp->smk_task = newsmack;
 
-	new->security = tsp;
 	commit_creds(new);
 	return size;
 }