[patch 11/11] unprivileged mounts: copy mount ownership on namespace cloning

[Miklos Szeredi]

From: Miklos Szeredi <mszeredi@xxxxxxx>

Mount ownership wasn't copied on CLONE_NEWNS.  Noticed by Al Viro.

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
---
 fs/namespace.c |    7 ++++++-
 fs/pnode.h     |    1 +
 2 files changed, 7 insertions(+), 1 deletion(-)

Index: linux/fs/namespace.c
===================================================================
--- linux.orig/fs/namespace.c	2008-03-17 20:55:53.000000000 +0100
+++ linux/fs/namespace.c	2008-03-17 20:55:53.000000000 +0100
@@ -585,6 +585,11 @@ static struct vfsmount *clone_mnt(struct
 	struct super_block *sb = old->mnt_sb;
 	struct vfsmount *mnt;
 
+	if ((flag & CL_COPYUSER) && (old->mnt_flags & MNT_USER)) {
+		owner = old->mnt_uid;
+		flag |= CL_SETUSER;
+	}
+
 	if (flag & CL_SETUSER) {
 		int err = reserve_user_mount();
 		if (err)
@@ -2141,7 +2146,7 @@ static struct mnt_namespace *dup_mnt_ns(
 	down_write(&namespace_sem);
 	/* First pass: copy the tree topology */
 	new_ns->root = copy_tree(mnt_ns->root, mnt_ns->root->mnt_root,
-					CL_COPY_ALL | CL_EXPIRE, 0);
+				 CL_COPY_ALL | CL_EXPIRE | CL_COPYUSER, 0);
 	if (IS_ERR(new_ns->root)) {
 		up_write(&namespace_sem);
 		kfree(new_ns);
Index: linux/fs/pnode.h
===================================================================
--- linux.orig/fs/pnode.h	2008-03-17 20:55:52.000000000 +0100
+++ linux/fs/pnode.h	2008-03-17 20:55:53.000000000 +0100
@@ -24,6 +24,7 @@
 #define CL_PRIVATE 		0x20
 #define CL_SETUSER		0x40
 #define CL_NOSUID		0x80
+#define CL_COPYUSER		0x100
 
 void set_mnt_shared(struct vfsmount *);
 void clear_mnt_shared(struct vfsmount *);

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