diff --git a/fs/namespace.c b/fs/namespace.c index 4d31f73e2561d4d0e19d85becc0223dda27b4710..7bdf7907413f0ea5f3c9e9c2de6b4002381e2064 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1886,8 +1886,14 @@ static int do_add_mount(struct mount *newmnt, struct path *path, int mnt_flags) return err; err = -EINVAL; - if (!(mnt_flags & MNT_SHRINKABLE) && !check_mnt(real_mount(path->mnt))) - goto unlock; + if (unlikely(!check_mnt(real_mount(path->mnt)))) { + /* that's acceptable only for automounts done in private ns */ + if (!(mnt_flags & MNT_SHRINKABLE)) + goto unlock; + /* ... and for those we'd better have mountpoint still alive */ + if (!real_mount(path->mnt)->mnt_ns) + goto unlock; + } /* Refuse the same filesystem on the same mount point */ err = -EBUSY;