Commit cd4a4017 authored Jan 07, 2015 by Eric W. Biederman

mnt: Fail collect_mounts when applied to unmounted mounts



The only users of collect_mounts are in audit_tree.c

In audit_trim_trees and audit_add_tree_rule the path passed into
collect_mounts is generated from kern_path passed an audit_tree
pathname which is guaranteed to be an absolute path.   In those cases
collect_mounts is obviously intended to work on mounted paths and
if a race results in paths that are unmounted when collect_mounts
it is reasonable to fail early.

The paths passed into audit_tag_tree don't have the absolute path
check.  But are used to play with fsnotify and otherwise interact with
the audit_trees, so again operating only on mounted paths appears
reasonable.

Avoid having to worry about what happens when we try and audit
unmounted filesystems by restricting collect_mounts to mounts
that appear in the mount tree.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

parent 0c56fe31

fs/namespace.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -1669,6 +1669,9 @@ struct vfsmount collect_mounts(struct path path)
		{
		struct mount *tree;
		namespace_lock();
		if (!check_mnt(real_mount(path->mnt)))
		tree = ERR_PTR(-EINVAL);
		else
		tree = copy_tree(real_mount(path->mnt), path->dentry,
		CL_COPY_ALL \| CL_PRIVATE);
		namespace_unlock();