From: Eric W. Biederman Date: Mon, 20 Jan 2014 23:26:15 +0000 (-0800) Subject: vfs: Is mounted should be testing mnt_ns for NULL or error. X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=260a459d2e39761fbd39803497205ce1690bc7b1;p=deliverable%2Flinux.git vfs: Is mounted should be testing mnt_ns for NULL or error. A bug was introduced with the is_mounted helper function in commit f7a99c5b7c8bd3d3f533c8b38274e33f3da9096e Author: Al Viro 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 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. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" Signed-off-by: Al Viro --- diff --git a/fs/mount.h b/fs/mount.h index d64c594be6c4..a17458ca6f29 100644 --- a/fs/mount.h +++ b/fs/mount.h @@ -74,7 +74,7 @@ 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 *);