diff options
| -rw-r--r-- | fs/mount.h | 7 | ||||
| -rw-r--r-- | fs/namespace.c | 28 |
2 files changed, 10 insertions, 25 deletions
diff --git a/fs/mount.h b/fs/mount.h index f10776003643..f20e6ed845fe 100644 --- a/fs/mount.h +++ b/fs/mount.h @@ -161,6 +161,13 @@ static inline bool is_anon_ns(struct mnt_namespace *ns) return ns->seq == 0; } +static inline bool anon_ns_root(const struct mount *m) +{ + struct mnt_namespace *ns = READ_ONCE(m->mnt_ns); + + return !IS_ERR_OR_NULL(ns) && is_anon_ns(ns) && m == ns->root; +} + static inline bool mnt_ns_attached(const struct mount *mnt) { return !RB_EMPTY_NODE(&mnt->mnt_node); diff --git a/fs/namespace.c b/fs/namespace.c index c4feb8315978..ea01fea2ac93 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2480,9 +2480,7 @@ struct vfsmount *clone_private_mount(const struct path *path) * loops get created. */ if (!check_mnt(old_mnt)) { - if (!is_mounted(&old_mnt->mnt) || - !is_anon_ns(old_mnt->mnt_ns) || - mnt_has_parent(old_mnt)) + if (!anon_ns_root(old_mnt)) return ERR_PTR(-EINVAL); if (!check_for_nsfs_mounts(old_mnt)) @@ -3649,9 +3647,6 @@ static int do_move_mount(struct path *old_path, ns = old->mnt_ns; err = -EINVAL; - /* The thing moved must be mounted... */ - if (!is_mounted(&old->mnt)) - goto out; if (check_mnt(old)) { /* if the source is in our namespace... */ @@ -3664,10 +3659,8 @@ static int do_move_mount(struct path *old_path, } else { /* * otherwise the source must be the root of some anon namespace. - * AV: check for mount being root of an anon namespace is worth - * an inlined predicate... */ - if (!is_anon_ns(ns) || mnt_has_parent(old)) + if (!anon_ns_root(old)) goto out; /* * Bail out early if the target is within the same namespace - @@ -5028,22 +5021,7 @@ static int do_mount_setattr(struct path *path, struct mount_kattr *kattr) err = -EINVAL; lock_mount_hash(); - /* Ensure that this isn't anything purely vfs internal. */ - if (!is_mounted(&mnt->mnt)) - goto out; - - /* - * If this is an attached mount make sure it's located in the callers - * mount namespace. If it's not don't let the caller interact with it. - * - * If this mount doesn't have a parent it's most often simply a - * detached mount with an anonymous mount namespace. IOW, something - * that's simply not attached yet. But there are apparently also users - * that do change mount properties on the rootfs itself. That obviously - * neither has a parent nor is it a detached mount so we cannot - * unconditionally check for detached mounts. - */ - if ((mnt_has_parent(mnt) || !is_anon_ns(mnt->mnt_ns)) && !check_mnt(mnt)) + if (!anon_ns_root(mnt) && !check_mnt(mnt)) goto out; /* |