This is a note to let you know that I've just added the patch titled mnt: Update detach_mounts to leave mounts connected to the 4.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mnt-update-detach_mounts-to-leave-mounts-connected.patch and it can be found in the queue-4.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From e0c9c0afd2fc958ffa34b697972721d81df8a56f Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Date: Wed, 1 Apr 2015 18:30:06 -0500 Subject: mnt: Update detach_mounts to leave mounts connected From: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> commit e0c9c0afd2fc958ffa34b697972721d81df8a56f upstream. Now that it is possible to lazily unmount an entire mount tree and leave the individual mounts connected to each other add a new flag UMOUNT_CONNECTED to umount_tree to force this behavior and use this flag in detach_mounts. This closes a bug where the deletion of a file or directory could trigger an unmount and reveal data under a mount point. Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/namespace.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1350,6 +1350,7 @@ static inline void namespace_lock(void) enum umount_tree_flags { UMOUNT_SYNC = 1, UMOUNT_PROPAGATE = 2, + UMOUNT_CONNECTED = 4, }; /* * mount_lock must be held @@ -1388,7 +1389,10 @@ static void umount_tree(struct mount *mn if (how & UMOUNT_SYNC) p->mnt.mnt_flags |= MNT_SYNC_UMOUNT; - disconnect = !IS_MNT_LOCKED_AND_LAZY(p); + disconnect = !(((how & UMOUNT_CONNECTED) && + mnt_has_parent(p) && + (p->mnt_parent->mnt.mnt_flags & MNT_UMOUNT)) || + IS_MNT_LOCKED_AND_LAZY(p)); pin_insert_group(&p->mnt_umount, &p->mnt_parent->mnt, disconnect ? &unmounted : NULL); @@ -1531,7 +1535,7 @@ void __detach_mounts(struct dentry *dent umount_mnt(p); } } - else umount_tree(mnt, 0); + else umount_tree(mnt, UMOUNT_CONNECTED); } unlock_mount_hash(); put_mountpoint(mp); Patches currently in stable-queue which might be from ebiederm@xxxxxxxxxxxx are queue-4.0/mnt-don-t-propagate-umounts-in-__detach_mounts.patch queue-4.0/mnt-add-mnt_umount-flag.patch queue-4.0/mnt-honor-mnt_locked-when-detaching-mounts.patch queue-4.0/mnt-delay-removal-from-the-mount-hash.patch queue-4.0/mnt-on-an-unmount-propagate-clearing-of-mnt_locked.patch queue-4.0/mnt-don-t-propagate-unmounts-to-locked-mounts.patch queue-4.0/mnt-factor-out-unhash_mnt-from-detach_mnt-and-umount_tree.patch queue-4.0/mnt-factor-umount_mnt-from-umount_tree.patch queue-4.0/mnt-fix-the-error-check-in-__detach_mounts.patch queue-4.0/mnt-update-detach_mounts-to-leave-mounts-connected.patch queue-4.0/mnt-improve-the-umount_tree-flags.patch queue-4.0/mnt-in-umount_tree-reuse-mnt_list-instead-of-mnt_hash.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html