diff --git a/lib/commonio.c b/lib/commonio.c
index 03e1d755..d06b8e7d 100644
--- a/lib/commonio.c
+++ b/lib/commonio.c
@@ -375,10 +375,11 @@ bool commonio_present (const struct commonio_db *db)
 
 int commonio_lock_nowait (struct commonio_db *db, bool log)
 {
-	char* file;
-	char* lock;
+	char* file = NULL;
+	char* lock = NULL;
 	size_t lock_file_len;
 	size_t file_len;
+	int err;
 
 	if (db->locked) {
 		return 1;
@@ -386,26 +387,36 @@ int commonio_lock_nowait (struct commonio_db *db, bool log)
 	file_len = strlen(db->filename) + 11;/* %lu max size */
 	lock_file_len = strlen(db->filename) + 6; /* sizeof ".lock" */
 	file = (char*)malloc(file_len);
+	if(file == NULL) {
+		err = ENOMEM;
+		goto cleanup_ENOMEM;
+	}
 	lock = (char*)malloc(lock_file_len);
+	if(lock == NULL) {
+		err = ENOMEM;
+		goto cleanup_ENOMEM;
+	}
 	snprintf (file, file_len, "%s.%lu",
 	          db->filename, (unsigned long) getpid ());
 	snprintf (lock, lock_file_len, "%s.lock", db->filename);
 	if (do_lock_file (file, lock, log) != 0) {
 		db->locked = true;
 		lock_count++;
-		free(file);
-		free(lock);
-		return 1;
+		err = 1;
 	}
-	free(file);
-	free(lock);
-	return 0;
+cleanup_ENOMEM:
+	if(file)
+		free(file);
+	if(lock)
+		free(lock);
+	return err;
 }
 
 
 int commonio_lock (struct commonio_db *db)
 {
-#ifdef HAVE_LCKPWDF
+/*#ifdef HAVE_LCKPWDF*/ /* not compatible with prefix option*/
+#if 0
 	/*
 	 * only if the system libc has a real lckpwdf() - the one from
 	 * lockpw.c calls us and would cause infinite recursion!
diff --git a/libmisc/prefix_flag.c b/libmisc/prefix_flag.c
index 4115aa11..6581235e 100644
--- a/libmisc/prefix_flag.c
+++ b/libmisc/prefix_flag.c
@@ -168,9 +168,8 @@ extern struct group *prefix_getgrnam(const char *name)
 		fclose(fg);
 		return grp;
 	}
-	else {
-		return getgrnam(name);
-	}
+	
+	return getgrnam(name);
 }
 
 extern struct group *prefix_getgrgid(gid_t gid)
@@ -189,9 +188,8 @@ extern struct group *prefix_getgrgid(gid_t gid)
 		fclose(fg);
 		return grp;
 	}
-	else {
-		return getgrgid(gid);
-	}
+
+	return getgrgid(gid);
 }
 
 extern struct passwd *prefix_getpwuid(uid_t uid)
diff --git a/src/userdel.c b/src/userdel.c
index 705da850..c8de1d31 100644
--- a/src/userdel.c
+++ b/src/userdel.c
@@ -835,7 +835,7 @@ static int remove_mailbox (void)
 	}
 
 	len = strlen (prefix) + strlen (maildir) + strlen (user_name) + 2;
-	mailfile = alloca (len);
+	mailfile = xmalloc (len);
 
 	if (prefix[0]) {
 		(void) snprintf (mailfile, len, "%s/%s/%s",
@@ -852,6 +852,7 @@ static int remove_mailbox (void)
 			fprintf (stderr,
 			         _("%s: %s mail spool (%s) not found\n"),
 			         Prog, user_name, mailfile);
+			free(mailfile);
 			return 0;
 		} else {
 			fprintf (stderr,
@@ -864,6 +865,7 @@ static int remove_mailbox (void)
 			              user_name, (unsigned int) user_id,
 			              SHADOW_AUDIT_FAILURE);
 #endif				/* WITH_AUDIT */
+			free(mailfile);
 			return -1;
 		}
 	}
@@ -892,6 +894,7 @@ static int remove_mailbox (void)
 			              SHADOW_AUDIT_SUCCESS);
 		}
 #endif				/* WITH_AUDIT */
+		free(mailfile);
 		return errors;
 	}
 	i = is_owner (user_id, mailfile);
@@ -908,8 +911,10 @@ static int remove_mailbox (void)
 		              user_name, (unsigned int) user_id,
 		              SHADOW_AUDIT_FAILURE);
 #endif				/* WITH_AUDIT */
+		free(mailfile);
 		return 1;
 	} else if (i == -1) {
+		free(mailfile);
 		return 0;		/* mailbox doesn't exist */
 	}
 	if (unlink (mailfile) != 0) {
@@ -935,6 +940,7 @@ static int remove_mailbox (void)
 		              SHADOW_AUDIT_SUCCESS);
 	}
 #endif				/* WITH_AUDIT */
+	free(mailfile);
 	return errors;
 }