[3.11.y.z extended stable] Patch "vfs: Is mounted should be testing mnt_ns for NULL or error." has been added to staging queue
Luis Henriques
luis.henriques at canonical.com
Wed Feb 5 13:15:24 UTC 2014
This is a note to let you know that I have just added a patch titled
vfs: Is mounted should be testing mnt_ns for NULL or error.
to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree
which can be found at:
http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Luis
------
>From 0d42f98074d10ffde10817bcb3d12e084bd20e9c Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm at xmission.com>
Date: Mon, 20 Jan 2014 15:26:15 -0800
Subject: vfs: Is mounted should be testing mnt_ns for NULL or error.
commit 260a459d2e39761fbd39803497205ce1690bc7b1 upstream.
A bug was introduced with the is_mounted helper function in
commit f7a99c5b7c8bd3d3f533c8b38274e33f3da9096e
Author: Al Viro <viro at zeniv.linux.org.uk>
Date: Sat Jun 9 00:59:08 2012 -0400
get rid of ->mnt_longterm
it's enough to set ->mnt_ns of internal vfsmounts to something
distinct from all struct mnt_namespace out there; then we can
just use the check for ->mnt_ns != NULL in the fast path of
mntput_no_expire()
Signed-off-by: Al Viro <viro at zeniv.linux.org.uk>
The intent was to test if the real_mount(vfsmount)->mnt_ns was
NULL_OR_ERR but the code is actually testing real_mount(vfsmount)
and always returning true.
The result is d_absolute_path returning paths it should be hiding.
Signed-off-by: "Eric W. Biederman" <ebiederm at xmission.com>
Signed-off-by: Al Viro <viro at zeniv.linux.org.uk>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
fs/mount.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/mount.h b/fs/mount.h
index 64a8581..68d80bd 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -73,7 +73,7 @@ static inline int mnt_has_parent(struct mount *mnt)
static inline int is_mounted(struct vfsmount *mnt)
{
/* neither detached nor internal? */
- return !IS_ERR_OR_NULL(real_mount(mnt));
+ return !IS_ERR_OR_NULL(real_mount(mnt)->mnt_ns);
}
extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int);
--
1.8.3.2
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