Module Name: src
Committed By: mlelstv
Date: Tue Feb 19 06:55:28 UTC 2019
Modified Files:
src/sys/kern: vfs_syscalls.c
Log Message:
Don't allow MNT_UNION on the root, there is no covered filesystem.
Fixes PR 53850
To generate a diff of this commit:
cvs rdiff -u -r1.524 -r1.525 src/sys/kern/vfs_syscalls.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/vfs_syscalls.c
diff -u src/sys/kern/vfs_syscalls.c:1.524 src/sys/kern/vfs_syscalls.c:1.525
--- src/sys/kern/vfs_syscalls.c:1.524 Tue Feb 5 13:50:10 2019
+++ src/sys/kern/vfs_syscalls.c Tue Feb 19 06:55:28 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: vfs_syscalls.c,v 1.524 2019/02/05 13:50:10 kamil Exp $ */
+/* $NetBSD: vfs_syscalls.c,v 1.525 2019/02/19 06:55:28 mlelstv Exp $ */
/*-
* Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@@ -70,7 +70,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_syscalls.c,v 1.524 2019/02/05 13:50:10 kamil Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_syscalls.c,v 1.525 2019/02/19 06:55:28 mlelstv Exp $");
#ifdef _KERNEL_OPT
#include "opt_fileassoc.h"
@@ -278,6 +278,15 @@ mount_update(struct lwp *l, struct vnode
goto out;
}
+ /*
+ * Enabling MNT_UNION requires a covered mountpoint and
+ * must not happen on the root mount.
+ */
+ if ((flags & MNT_UNION) != 0 && mp->mnt_vnodecovered == NULLVP) {
+ error = EOPNOTSUPP;
+ goto out;
+ }
+
error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT,
KAUTH_REQ_SYSTEM_MOUNT_UPDATE, mp, KAUTH_ARG(flags), data);
if (error)
