From e79c6a4fc923eed2bdd3b716e0f01414847db90a Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Wed, 10 Aug 2016 14:36:02 -0700 Subject: 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" Signed-off-by: Dmitry Torokhov Signed-off-by: David S. Miller --- net/sysctl_net.c | 29 ++++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-) (limited to 'net/sysctl_net.c') diff --git a/net/sysctl_net.c b/net/sysctl_net.c index 46a71c701e7c..5bc1a3d57401 100644 --- a/net/sysctl_net.c +++ b/net/sysctl_net.c @@ -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) -- cgit v1.2.3