diff options
| -rw-r--r-- | fs/namespace.c | 59 | ||||
| -rw-r--r-- | fs/pnode.c | 5 | ||||
| -rw-r--r-- | fs/pnode.h | 3 |
3 files changed, 38 insertions, 29 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index a677b59efd74..9ed2f2930dfd 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1013,27 +1013,6 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root, mnt->mnt.mnt_flags = old->mnt.mnt_flags; mnt->mnt.mnt_flags &= ~(MNT_WRITE_HOLD|MNT_MARKED|MNT_INTERNAL); - /* Don't allow unprivileged users to change mount flags */ - if (flag & CL_UNPRIVILEGED) { - mnt->mnt.mnt_flags |= MNT_LOCK_ATIME; - - if (mnt->mnt.mnt_flags & MNT_READONLY) - mnt->mnt.mnt_flags |= MNT_LOCK_READONLY; - - if (mnt->mnt.mnt_flags & MNT_NODEV) - mnt->mnt.mnt_flags |= MNT_LOCK_NODEV; - - if (mnt->mnt.mnt_flags & MNT_NOSUID) - mnt->mnt.mnt_flags |= MNT_LOCK_NOSUID; - - if (mnt->mnt.mnt_flags & MNT_NOEXEC) - mnt->mnt.mnt_flags |= MNT_LOCK_NOEXEC; - } - - /* Don't allow unprivileged users to reveal what is under a mount */ - if ((flag & CL_UNPRIVILEGED) && - (!(flag & CL_EXPIRE) || list_empty(&old->mnt_expire))) - mnt->mnt.mnt_flags |= MNT_LOCKED; atomic_inc(&sb->s_active); mnt->mnt.mnt_sb = sb; @@ -1837,6 +1816,33 @@ int iterate_mounts(int (*f)(struct vfsmount *, void *), void *arg, return 0; } +static void lock_mnt_tree(struct mount *mnt) +{ + struct mount *p; + + for (p = mnt; p; p = next_mnt(p, mnt)) { + int flags = p->mnt.mnt_flags; + /* Don't allow unprivileged users to change mount flags */ + flags |= MNT_LOCK_ATIME; + + if (flags & MNT_READONLY) + flags |= MNT_LOCK_READONLY; + + if (flags & MNT_NODEV) + flags |= MNT_LOCK_NODEV; + + if (flags & MNT_NOSUID) + flags |= MNT_LOCK_NOSUID; + + if (flags & MNT_NOEXEC) + flags |= MNT_LOCK_NOEXEC; + /* Don't allow unprivileged users to reveal what is under a mount */ + if (list_empty(&p->mnt_expire)) + flags |= MNT_LOCKED; + p->mnt.mnt_flags = flags; + } +} + static void cleanup_group_ids(struct mount *mnt, struct mount *end) { struct mount *p; @@ -1954,6 +1960,7 @@ static int attach_recursive_mnt(struct mount *source_mnt, struct mountpoint *dest_mp, struct path *parent_path) { + struct user_namespace *user_ns = current->nsproxy->mnt_ns->user_ns; HLIST_HEAD(tree_list); struct mnt_namespace *ns = dest_mnt->mnt_ns; struct mountpoint *smp; @@ -2004,6 +2011,9 @@ static int attach_recursive_mnt(struct mount *source_mnt, child->mnt_mountpoint); if (q) mnt_change_mountpoint(child, smp, q); + /* Notice when we are propagating across user namespaces */ + if (child->mnt_parent->mnt_ns->user_ns != user_ns) + lock_mnt_tree(child); commit_tree(child); } put_mountpoint(smp); @@ -2941,13 +2951,18 @@ struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns, /* First pass: copy the tree topology */ copy_flags = CL_COPY_UNBINDABLE | CL_EXPIRE; if (user_ns != ns->user_ns) - copy_flags |= CL_SHARED_TO_SLAVE | CL_UNPRIVILEGED; + copy_flags |= CL_SHARED_TO_SLAVE; new = copy_tree(old, old->mnt.mnt_root, copy_flags); if (IS_ERR(new)) { namespace_unlock(); free_mnt_ns(new_ns); return ERR_CAST(new); } + if (user_ns != ns->user_ns) { + lock_mount_hash(); + lock_mnt_tree(new); + unlock_mount_hash(); + } new_ns->root = new; list_add_tail(&new_ns->list, &new->mnt_list); diff --git a/fs/pnode.c b/fs/pnode.c index 1100e810d855..7ea6cfb65077 100644 --- a/fs/pnode.c +++ b/fs/pnode.c @@ -214,7 +214,6 @@ static struct mount *next_group(struct mount *m, struct mount *origin) } /* all accesses are serialized by namespace_sem */ -static struct user_namespace *user_ns; static struct mount *last_dest, *first_source, *last_source, *dest_master; static struct mountpoint *mp; static struct hlist_head *list; @@ -260,9 +259,6 @@ static int propagate_one(struct mount *m) type |= CL_MAKE_SHARED; } - /* Notice when we are propagating across user namespaces */ - if (m->mnt_ns->user_ns != user_ns) - type |= CL_UNPRIVILEGED; child = copy_tree(last_source, last_source->mnt.mnt_root, type); if (IS_ERR(child)) return PTR_ERR(child); @@ -303,7 +299,6 @@ int propagate_mnt(struct mount *dest_mnt, struct mountpoint *dest_mp, * propagate_one(); everything is serialized by namespace_sem, * so globals will do just fine. */ - user_ns = current->nsproxy->mnt_ns->user_ns; last_dest = dest_mnt; first_source = source_mnt; last_source = source_mnt; diff --git a/fs/pnode.h b/fs/pnode.h index dc87e65becd2..3960a83666cf 100644 --- a/fs/pnode.h +++ b/fs/pnode.h @@ -27,8 +27,7 @@ #define CL_MAKE_SHARED 0x08 #define CL_PRIVATE 0x10 #define CL_SHARED_TO_SLAVE 0x20 -#define CL_UNPRIVILEGED 0x40 -#define CL_COPY_MNT_NS_FILE 0x80 +#define CL_COPY_MNT_NS_FILE 0x40 #define CL_COPY_ALL (CL_COPY_UNBINDABLE | CL_COPY_MNT_NS_FILE) |