net: make net namespace sysctls belong to container's owner

If net namespace is attached to a user namespace let's make container's
root owner of sysctls affecting said network namespace instead of global
root.

This also allows us to clean up net_ctl_permissions() because we do not
need to fudge permissions anymore for the container's owner since it now
owns the objects in question.

Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dmitry Torokhov
2016-08-10 14:36:02 -07:00
committed by David S. Miller
parent c110486f6c
commit e79c6a4fc9
3 changed files with 29 additions and 9 deletions

View File

@@ -42,26 +42,37 @@ static int net_ctl_permissions(struct ctl_table_header *head,
struct ctl_table *table)
{
struct net *net = container_of(head->set, struct net, sysctls);
kuid_t root_uid = make_kuid(net->user_ns, 0);
kgid_t root_gid = make_kgid(net->user_ns, 0);
/* Allow network administrator to have same access as root. */
if (ns_capable_noaudit(net->user_ns, CAP_NET_ADMIN) ||
uid_eq(root_uid, current_euid())) {
if (ns_capable(net->user_ns, CAP_NET_ADMIN)) {
int mode = (table->mode >> 6) & 7;
return (mode << 6) | (mode << 3) | mode;
}
/* Allow netns root group to have the same access as the root group */
if (in_egroup_p(root_gid)) {
int mode = (table->mode >> 3) & 7;
return (mode << 3) | mode;
}
return table->mode;
}
static void net_ctl_set_ownership(struct ctl_table_header *head,
struct ctl_table *table,
kuid_t *uid, kgid_t *gid)
{
struct net *net = container_of(head->set, struct net, sysctls);
kuid_t ns_root_uid;
kgid_t ns_root_gid;
ns_root_uid = make_kuid(net->user_ns, 0);
if (uid_valid(ns_root_uid))
*uid = ns_root_uid;
ns_root_gid = make_kgid(net->user_ns, 0);
if (gid_valid(ns_root_gid))
*gid = ns_root_gid;
}
static struct ctl_table_root net_sysctl_root = {
.lookup = net_ctl_header_lookup,
.permissions = net_ctl_permissions,
.set_ownership = net_ctl_set_ownership,
};
static int __net_init sysctl_net_init(struct net *net)