Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e0c9c0af authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

mnt: Update detach_mounts to leave mounts connected 



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.

Cc: stable@vger.kernel.org
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
parent f53e5797

fs/namespace.c

+6 −2
Original line number Diff line number Diff line
@@ -1348,6 +1348,7 @@ static inline void namespace_lock(void) 
enum umount_tree_flags {

	UMOUNT_SYNC = 1,

	UMOUNT_PROPAGATE = 2,

	UMOUNT_CONNECTED = 4,

};

/*

 * mount_lock must be held
@@ -1386,7 +1387,10 @@ static void umount_tree(struct mount *mnt, enum umount_tree_flags how) 
		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);
@@ -1529,7 +1533,7 @@ void __detach_mounts(struct dentry *dentry) 
				umount_mnt(p);

			}

		}

		else umount_tree(mnt, 0);

		else umount_tree(mnt, UMOUNT_CONNECTED);

	}

	unlock_mount_hash();

	put_mountpoint(mp);