b207a290ea
This patch provides finer grained permissions for the audit family of Netlink sockets under SELinux. 1. We need a way to differentiate between privileged and unprivileged reads of kernel data maintained by the audit subsystem. The AUDIT_GET operation is unprivileged: it returns the current status of the audit subsystem (e.g. whether it's enabled etc.). The AUDIT_LIST operation however returns a list of the current audit ruleset, which is considered privileged by the audit folk. To deal with this, a new SELinux permission has been implemented and applied to the operation: nlmsg_readpriv, which can be allocated to appropriately privileged domains. Unprivileged domains would only be allocated nlmsg_read. 2. There is a requirement for certain domains to generate audit events from userspace. These events need to be collected by the kernel, collated and transmitted sequentially back to the audit daemon. An example is user level login, an auditable event under CAPP, where login-related domains generate AUDIT_USER messages via PAM which are relayed back to auditd via the kernel. To prevent handing out nlmsg_write permissions to such domains, a new permission has been added, nlmsg_relay, which is intended for this type of purpose: data is passed via the kernel back to userspace but no privileged information is written to the kernel. Also, AUDIT_LOGIN messages are now valid only for kernel->user messaging, so this value has been removed from the SELinux nlmsgtab (which is only used to check user->kernel messages). Signed-off-by: James Morris <jmorris@redhat.com> Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
156 lines
4.9 KiB
C
156 lines
4.9 KiB
C
/*
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* Netlink message type permission tables, for user generated messages.
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*
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* Author: James Morris <jmorris@redhat.com>
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*
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* Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2,
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* as published by the Free Software Foundation.
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*/
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/skbuff.h>
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#include <linux/netlink.h>
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#include <linux/rtnetlink.h>
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#include <linux/if.h>
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#include <linux/netfilter_ipv4/ip_queue.h>
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#include <linux/tcp_diag.h>
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#include <linux/xfrm.h>
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#include <linux/audit.h>
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#include "flask.h"
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#include "av_permissions.h"
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struct nlmsg_perm
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{
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u16 nlmsg_type;
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u32 perm;
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};
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static struct nlmsg_perm nlmsg_route_perms[] =
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{
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{ RTM_NEWLINK, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_DELLINK, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_GETLINK, NETLINK_ROUTE_SOCKET__NLMSG_READ },
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{ RTM_SETLINK, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_NEWADDR, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_DELADDR, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_GETADDR, NETLINK_ROUTE_SOCKET__NLMSG_READ },
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{ RTM_NEWROUTE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_DELROUTE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_GETROUTE, NETLINK_ROUTE_SOCKET__NLMSG_READ },
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{ RTM_NEWNEIGH, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_DELNEIGH, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_GETNEIGH, NETLINK_ROUTE_SOCKET__NLMSG_READ },
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{ RTM_NEWRULE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_DELRULE, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_GETRULE, NETLINK_ROUTE_SOCKET__NLMSG_READ },
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{ RTM_NEWQDISC, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_DELQDISC, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_GETQDISC, NETLINK_ROUTE_SOCKET__NLMSG_READ },
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{ RTM_NEWTCLASS, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_DELTCLASS, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_GETTCLASS, NETLINK_ROUTE_SOCKET__NLMSG_READ },
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{ RTM_NEWTFILTER, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_DELTFILTER, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_GETTFILTER, NETLINK_ROUTE_SOCKET__NLMSG_READ },
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{ RTM_NEWACTION, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_DELACTION, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_GETACTION, NETLINK_ROUTE_SOCKET__NLMSG_READ },
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{ RTM_NEWPREFIX, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
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{ RTM_GETPREFIX, NETLINK_ROUTE_SOCKET__NLMSG_READ },
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{ RTM_GETMULTICAST, NETLINK_ROUTE_SOCKET__NLMSG_READ },
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{ RTM_GETANYCAST, NETLINK_ROUTE_SOCKET__NLMSG_READ },
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};
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static struct nlmsg_perm nlmsg_firewall_perms[] =
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{
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{ IPQM_MODE, NETLINK_FIREWALL_SOCKET__NLMSG_WRITE },
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{ IPQM_VERDICT, NETLINK_FIREWALL_SOCKET__NLMSG_WRITE },
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};
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static struct nlmsg_perm nlmsg_tcpdiag_perms[] =
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{
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{ TCPDIAG_GETSOCK, NETLINK_TCPDIAG_SOCKET__NLMSG_READ },
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};
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static struct nlmsg_perm nlmsg_xfrm_perms[] =
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{
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{ XFRM_MSG_NEWSA, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
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{ XFRM_MSG_DELSA, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
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{ XFRM_MSG_GETSA, NETLINK_XFRM_SOCKET__NLMSG_READ },
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{ XFRM_MSG_NEWPOLICY, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
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{ XFRM_MSG_DELPOLICY, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
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{ XFRM_MSG_GETPOLICY, NETLINK_XFRM_SOCKET__NLMSG_READ },
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{ XFRM_MSG_ALLOCSPI, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
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{ XFRM_MSG_UPDPOLICY, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
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{ XFRM_MSG_UPDSA, NETLINK_XFRM_SOCKET__NLMSG_WRITE },
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};
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static struct nlmsg_perm nlmsg_audit_perms[] =
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{
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{ AUDIT_GET, NETLINK_AUDIT_SOCKET__NLMSG_READ },
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{ AUDIT_SET, NETLINK_AUDIT_SOCKET__NLMSG_WRITE },
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{ AUDIT_LIST, NETLINK_AUDIT_SOCKET__NLMSG_READPRIV },
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{ AUDIT_ADD, NETLINK_AUDIT_SOCKET__NLMSG_WRITE },
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{ AUDIT_DEL, NETLINK_AUDIT_SOCKET__NLMSG_WRITE },
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{ AUDIT_USER, NETLINK_AUDIT_SOCKET__NLMSG_RELAY },
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};
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static int nlmsg_perm(u16 nlmsg_type, u32 *perm, struct nlmsg_perm *tab, size_t tabsize)
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{
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int i, err = -EINVAL;
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for (i = 0; i < tabsize/sizeof(struct nlmsg_perm); i++)
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if (nlmsg_type == tab[i].nlmsg_type) {
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*perm = tab[i].perm;
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err = 0;
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break;
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}
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return err;
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}
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int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm)
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{
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int err = 0;
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switch (sclass) {
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case SECCLASS_NETLINK_ROUTE_SOCKET:
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err = nlmsg_perm(nlmsg_type, perm, nlmsg_route_perms,
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sizeof(nlmsg_route_perms));
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break;
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case SECCLASS_NETLINK_FIREWALL_SOCKET:
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case SECCLASS_NETLINK_IP6FW_SOCKET:
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err = nlmsg_perm(nlmsg_type, perm, nlmsg_firewall_perms,
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sizeof(nlmsg_firewall_perms));
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break;
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case SECCLASS_NETLINK_TCPDIAG_SOCKET:
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err = nlmsg_perm(nlmsg_type, perm, nlmsg_tcpdiag_perms,
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sizeof(nlmsg_tcpdiag_perms));
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break;
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case SECCLASS_NETLINK_XFRM_SOCKET:
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err = nlmsg_perm(nlmsg_type, perm, nlmsg_xfrm_perms,
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sizeof(nlmsg_xfrm_perms));
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break;
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case SECCLASS_NETLINK_AUDIT_SOCKET:
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err = nlmsg_perm(nlmsg_type, perm, nlmsg_audit_perms,
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sizeof(nlmsg_audit_perms));
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break;
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/* No messaging from userspace, or class unknown/unhandled */
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default:
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err = -ENOENT;
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break;
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}
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return err;
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}
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