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Commit 37657da3 authored by Eric W. Biederman's avatar Eric W. Biederman
Browse files

userns: Allow setting a userns mapping to your current uid. 



Acked-by: default avatarSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
parent 7fa294c8

kernel/user_namespace.c

+15 −0
Original line number Diff line number Diff line
@@ -709,6 +709,21 @@ ssize_t proc_projid_map_write(struct file *file, const char __user *buf, size_t 
static bool new_idmap_permitted(struct user_namespace *ns, int cap_setid,

				struct uid_gid_map *new_map)

{

	/* Allow mapping to your own filesystem ids */

	if ((new_map->nr_extents == 1) && (new_map->extent[0].count == 1)) {

		u32 id = new_map->extent[0].lower_first;

		if (cap_setid == CAP_SETUID) {

			kuid_t uid = make_kuid(ns->parent, id);

			if (uid_eq(uid, current_fsuid()))

				return true;

		}

		else if (cap_setid == CAP_SETGID) {

			kgid_t gid = make_kgid(ns->parent, id);

			if (gid_eq(gid, current_fsgid()))

				return true;

		}

	}



	/* Allow anyone to set a mapping that doesn't require privilege */

	if (!cap_valid(cap_setid))

		return true;