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-Tag: firefly_0821_release~3679^2~2966 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=9a8bd082503f4f91176d8fe0b91a23c5b768008e;p=firefly-linux-kernel-4.4.55.git 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 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. Signed-off-by: "Eric W. Biederman" Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/mount.h b/fs/mount.h index 64a858143ff9..68d80bdcd081 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);