net: Use netlink_ns_capable to verify the permisions of netlink messages

[ Upstream commit 90f62cf30a78721641e08737bda787552428061e ]

It is possible by passing a netlink socket to a more privileged
executable and then to fool that executable into writing to the socket
data that happens to be valid netlink message to do something that
privileged executable did not intend to do.

To keep this from happening replace bare capable and ns_capable calls
with netlink_capable, netlink_net_calls and netlink_ns_capable calls.
Which act the same as the previous calls except they verify that the
opener of the socket had the desired permissions as well.

Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/crypto/crypto_user.c b/crypto/crypto_user.c
index 1512e41cd93d74a4e7ab3fde6809e64468f797a8..43665d0d0905ddddf018fe68655c1ff7685b0b9e 100644 (file)
--- a/crypto/crypto_user.c
+++ b/crypto/crypto_user.c
@@ -466,7 +466,7 @@ static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
        type -= CRYPTO_MSG_BASE;
        link = &crypto_dispatch[type];
 
-       if (!capable(CAP_NET_ADMIN))
+       if (!netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&

diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c
index 18c5b9b16645dfa49a218d4b12253240f97310b7..3165811e2407df9bdc8242640dab50558c37db73 100644 (file)
--- a/drivers/connector/cn_proc.c
+++ b/drivers/connector/cn_proc.c
@@ -369,7 +369,7 @@ static void cn_proc_mcast_ctl(struct cn_msg *msg,
                return;
 
        /* Can only change if privileged. */
-       if (!capable(CAP_NET_ADMIN)) {
+       if (!__netlink_ns_capable(nsp, &init_user_ns, CAP_NET_ADMIN)) {
                err = EPERM;
                goto out;
        }

diff --git a/drivers/scsi/scsi_netlink.c b/drivers/scsi/scsi_netlink.c
index fe30ea94ffe67ef4e5d355fdc9cdcb71eee9e0d7..109802f776ed71cea6857eda9ae6ccc3e0b41f80 100644 (file)
--- a/drivers/scsi/scsi_netlink.c
+++ b/drivers/scsi/scsi_netlink.c
@@ -77,7 +77,7 @@ scsi_nl_rcv_msg(struct sk_buff *skb)
                        goto next_msg;
                }
 
-               if (!capable(CAP_SYS_ADMIN)) {
+               if (!netlink_capable(skb, CAP_SYS_ADMIN)) {
                        err = -EPERM;
                        goto next_msg;
                }

diff --git a/kernel/audit.c b/kernel/audit.c
index 50512d11a4450fe3c32ca4ebac16ed6f52a38dc5..197a496587a61f1bb9baa284bcede9dcb715a711 100644 (file)
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -593,13 +593,13 @@ static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
        case AUDIT_TTY_SET:
        case AUDIT_TRIM:
        case AUDIT_MAKE_EQUIV:
-               if (!capable(CAP_AUDIT_CONTROL))
+               if (!netlink_capable(skb, CAP_AUDIT_CONTROL))
                        err = -EPERM;
                break;
        case AUDIT_USER:
        case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
        case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
-               if (!capable(CAP_AUDIT_WRITE))
+               if (!netlink_capable(skb, CAP_AUDIT_WRITE))
                        err = -EPERM;
                break;
        default:  /* bad msg */

diff --git a/net/can/gw.c b/net/can/gw.c
index 3f9b0f3a281876e7d8ec7de0366ed98712759aad..233ce53c1852429b0fd88f82455840d9d6d86312 100644 (file)
--- a/net/can/gw.c
+++ b/net/can/gw.c
@@ -804,7 +804,7 @@ static int cgw_create_job(struct sk_buff *skb,  struct nlmsghdr *nlh)
        u8 limhops = 0;
        int err = 0;
 
-       if (!capable(CAP_NET_ADMIN))
+       if (!netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        if (nlmsg_len(nlh) < sizeof(*r))
@@ -900,7 +900,7 @@ static int cgw_remove_job(struct sk_buff *skb, struct nlmsghdr *nlh)
        u8 limhops = 0;
        int err = 0;
 
-       if (!capable(CAP_NET_ADMIN))
+       if (!netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        if (nlmsg_len(nlh) < sizeof(*r))

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 7b03d44b7be43c6215a2fe5cc46c43e7c99c29a3..e46ced7c9c33b8fc99a847f35af033fe91a05cc3 100644 (file)
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1366,7 +1366,8 @@ static int do_set_master(struct net_device *dev, int ifindex)
        return 0;
 }
 
-static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
+static int do_setlink(const struct sk_buff *skb,
+                     struct net_device *dev, struct ifinfomsg *ifm,
                      struct nlattr **tb, char *ifname, int modified)
 {
        const struct net_device_ops *ops = dev->netdev_ops;
@@ -1378,7 +1379,7 @@ static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
                        err = PTR_ERR(net);
                        goto errout;
                }
-               if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) {
+               if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) {
                        err = -EPERM;
                        goto errout;
                }
@@ -1632,7 +1633,7 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh)
        if (err < 0)
                goto errout;
 
-       err = do_setlink(dev, ifm, tb, ifname, 0);
+       err = do_setlink(skb, dev, ifm, tb, ifname, 0);
 errout:
        return err;
 }
@@ -1750,7 +1751,8 @@ err:
 }
 EXPORT_SYMBOL(rtnl_create_link);
 
-static int rtnl_group_changelink(struct net *net, int group,
+static int rtnl_group_changelink(const struct sk_buff *skb,
+               struct net *net, int group,
                struct ifinfomsg *ifm,
                struct nlattr **tb)
 {
@@ -1759,7 +1761,7 @@ static int rtnl_group_changelink(struct net *net, int group,
 
        for_each_netdev(net, dev) {
                if (dev->group == group) {
-                       err = do_setlink(dev, ifm, tb, NULL, 0);
+                       err = do_setlink(skb, dev, ifm, tb, NULL, 0);
                        if (err < 0)
                                return err;
                }
@@ -1861,12 +1863,12 @@ replay:
                                modified = 1;
                        }
 
-                       return do_setlink(dev, ifm, tb, ifname, modified);
+                       return do_setlink(skb, dev, ifm, tb, ifname, modified);
                }
 
                if (!(nlh->nlmsg_flags & NLM_F_CREATE)) {
                        if (ifm->ifi_index == 0 && tb[IFLA_GROUP])
-                               return rtnl_group_changelink(net,
+                               return rtnl_group_changelink(skb, net,
                                                nla_get_u32(tb[IFLA_GROUP]),
                                                ifm, tb);
                        return -ENODEV;
@@ -2247,7 +2249,7 @@ static int rtnl_fdb_del(struct sk_buff *skb, struct nlmsghdr *nlh)
        int err = -EINVAL;
        __u8 *addr;
 
-       if (!capable(CAP_NET_ADMIN))
+       if (!netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX, NULL);
@@ -2699,7 +2701,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
        sz_idx = type>>2;
        kind = type&3;
 
-       if (kind != 2 && !ns_capable(net->user_ns, CAP_NET_ADMIN))
+       if (kind != 2 && !netlink_net_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {

diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index 40d5829ed36aaa6945c9c4c2056325b68ab64c03..1074ffb6d533993dd0332c04558192ed9d8373a8 100644 (file)
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -1670,7 +1670,7 @@ static int dcb_doit(struct sk_buff *skb, struct nlmsghdr *nlh)
        struct nlmsghdr *reply_nlh = NULL;
        const struct reply_func *fn;
 
-       if ((nlh->nlmsg_type == RTM_SETDCB) && !capable(CAP_NET_ADMIN))
+       if ((nlh->nlmsg_type == RTM_SETDCB) && !netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        ret = nlmsg_parse(nlh, sizeof(*dcb), tb, DCB_ATTR_MAX,

diff --git a/net/decnet/dn_dev.c b/net/decnet/dn_dev.c
index dd0dfb25f4b1c6945ab07a5190e7393abb42a3cc..70f254912a36415508c67e00f7933e4bac3ea48b 100644 (file)
--- a/net/decnet/dn_dev.c
+++ b/net/decnet/dn_dev.c
@@ -573,7 +573,7 @@ static int dn_nl_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh)
        struct dn_ifaddr __rcu **ifap;
        int err = -EINVAL;
 
-       if (!capable(CAP_NET_ADMIN))
+       if (!netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        if (!net_eq(net, &init_net))
@@ -617,7 +617,7 @@ static int dn_nl_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh)
        struct dn_ifaddr *ifa;
        int err;
 
-       if (!capable(CAP_NET_ADMIN))
+       if (!netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        if (!net_eq(net, &init_net))

diff --git a/net/decnet/dn_fib.c b/net/decnet/dn_fib.c
index 57dc159245ecfff38e318626cf0ea1ffa9db1cae..d332aefb0846f86a11d924e3e1e7ad23e279dda2 100644 (file)
--- a/net/decnet/dn_fib.c
+++ b/net/decnet/dn_fib.c
@@ -505,7 +505,7 @@ static int dn_fib_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
        struct nlattr *attrs[RTA_MAX+1];
        int err;
 
-       if (!capable(CAP_NET_ADMIN))
+       if (!netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        if (!net_eq(net, &init_net))
@@ -530,7 +530,7 @@ static int dn_fib_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
        struct nlattr *attrs[RTA_MAX+1];
        int err;
 
-       if (!capable(CAP_NET_ADMIN))
+       if (!netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        if (!net_eq(net, &init_net))

diff --git a/net/decnet/netfilter/dn_rtmsg.c b/net/decnet/netfilter/dn_rtmsg.c
index 2a7efe388344fdd37b10487c50ba3d712eedbf8a..f3dc69a41d63446d53bb24925c9dad8bdbef5e47 100644 (file)
--- a/net/decnet/netfilter/dn_rtmsg.c
+++ b/net/decnet/netfilter/dn_rtmsg.c
@@ -107,7 +107,7 @@ static inline void dnrmg_receive_user_skb(struct sk_buff *skb)
        if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
                return;
 
-       if (!capable(CAP_NET_ADMIN))
+       if (!netlink_capable(skb, CAP_NET_ADMIN))
                RCV_SKB_FAIL(-EPERM);
 
        /* Eventually we might send routing messages too */

diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index 572d87dc116ffa838d2f9f8838129156add7284e..0a03662bfbefbb41bc433999966196f38d7674bd 100644 (file)
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -147,7 +147,7 @@ static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
        const struct nfnetlink_subsystem *ss;
        int type, err;
 
-       if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+       if (!netlink_net_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        /* All the messages must at least contain nfgenmsg */

diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 0c741cec4d0d294d808ddc26fdaacecc3e6a0b94..c7408dd8fd9a868b2342f91ed338ca3559c9bf3d 100644 (file)
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -592,7 +592,7 @@ static int genl_family_rcv_msg(struct genl_family *family,
                return -EOPNOTSUPP;
 
        if ((ops->flags & GENL_ADMIN_PERM) &&
-           !capable(CAP_NET_ADMIN))
+           !netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        if ((nlh->nlmsg_flags & NLM_F_DUMP) == NLM_F_DUMP) {

diff --git a/net/packet/diag.c b/net/packet/diag.c
index 01cd1ac44ff51e11e54756aa4b175ca303c8ff72..674b0a65df6c02eb49d36869c969a1439982ab2e 100644 (file)
--- a/net/packet/diag.c
+++ b/net/packet/diag.c
@@ -193,7 +193,7 @@ static int packet_diag_dump(struct sk_buff *skb, struct netlink_callback *cb)
 
        net = sock_net(skb->sk);
        req = nlmsg_data(cb->nlh);
-       may_report_filterinfo = ns_capable(net->user_ns, CAP_NET_ADMIN);
+       may_report_filterinfo = netlink_net_capable(cb->skb, CAP_NET_ADMIN);
 
        mutex_lock(&net->packet.sklist_lock);
        sk_for_each(sk, &net->packet.sklist) {

diff --git a/net/phonet/pn_netlink.c b/net/phonet/pn_netlink.c
index dc15f430080831e74fade00799a661ab10cc6f84..b64151ade6b33a9cbacb0980d3ddbe03d8f7b4c8 100644 (file)
--- a/net/phonet/pn_netlink.c
+++ b/net/phonet/pn_netlink.c
@@ -70,10 +70,10 @@ static int addr_doit(struct sk_buff *skb, struct nlmsghdr *nlh)
        int err;
        u8 pnaddr;
 
-       if (!capable(CAP_NET_ADMIN))
+       if (!netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
-       if (!capable(CAP_SYS_ADMIN))
+       if (!netlink_capable(skb, CAP_SYS_ADMIN))
                return -EPERM;
 
        ASSERT_RTNL();
@@ -233,10 +233,10 @@ static int route_doit(struct sk_buff *skb, struct nlmsghdr *nlh)
        int err;
        u8 dst;
 
-       if (!capable(CAP_NET_ADMIN))
+       if (!netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
-       if (!capable(CAP_SYS_ADMIN))
+       if (!netlink_capable(skb, CAP_SYS_ADMIN))
                return -EPERM;
 
        ASSERT_RTNL();

diff --git a/net/sched/act_api.c b/net/sched/act_api.c
index fd7072827a40139c4ffba595aaa261282641e37f..15d46b9166debf2d4b832e4c837e3981b7401606 100644 (file)
--- a/net/sched/act_api.c
+++ b/net/sched/act_api.c
@@ -989,7 +989,7 @@ static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
        u32 portid = skb ? NETLINK_CB(skb).portid : 0;
        int ret = 0, ovr = 0;
 
-       if ((n->nlmsg_type != RTM_GETACTION) && !capable(CAP_NET_ADMIN))
+       if ((n->nlmsg_type != RTM_GETACTION) && !netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 8e118af9097345a500e1006bff6fa5c108435603..2ea40d1877a6cce9230b574463b12c637b8ac86e 100644 (file)
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -138,7 +138,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n)
        int err;
        int tp_created = 0;
 
-       if ((n->nlmsg_type != RTM_GETTFILTER) && !capable(CAP_NET_ADMIN))
+       if ((n->nlmsg_type != RTM_GETTFILTER) && !netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
 replay:

diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 2adda7fa2d390c4bb2aec883cf049df7e7cef9ef..3f5fe03fee7231578049e87addf4901bc95ae3dd 100644 (file)
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1076,7 +1076,7 @@ static int tc_get_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
        struct Qdisc *p = NULL;
        int err;
 
-       if ((n->nlmsg_type != RTM_GETQDISC) && !capable(CAP_NET_ADMIN))
+       if ((n->nlmsg_type != RTM_GETQDISC) && !netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);
@@ -1143,7 +1143,7 @@ static int tc_modify_qdisc(struct sk_buff *skb, struct nlmsghdr *n)
        struct Qdisc *q, *p;
        int err;
 
-       if (!capable(CAP_NET_ADMIN))
+       if (!netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
 replay:
@@ -1483,7 +1483,7 @@ static int tc_ctl_tclass(struct sk_buff *skb, struct nlmsghdr *n)
        u32 qid;
        int err;
 
-       if ((n->nlmsg_type != RTM_GETTCLASS) && !capable(CAP_NET_ADMIN))
+       if ((n->nlmsg_type != RTM_GETTCLASS) && !netlink_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        err = nlmsg_parse(n, sizeof(*tcm), tca, TCA_MAX, NULL);

diff --git a/net/tipc/netlink.c b/net/tipc/netlink.c
index 8bcd4985d0fb341f795346f06c55d1f059c4c643..1e6081fb60788f35d5413dd799e107652177ba97 100644 (file)
--- a/net/tipc/netlink.c
+++ b/net/tipc/netlink.c
@@ -47,7 +47,7 @@ static int handle_cmd(struct sk_buff *skb, struct genl_info *info)
        int hdr_space = nlmsg_total_size(GENL_HDRLEN + TIPC_GENL_HDRLEN);
        u16 cmd;
 
-       if ((req_userhdr->cmd & 0xC000) && (!capable(CAP_NET_ADMIN)))
+       if ((req_userhdr->cmd & 0xC000) && (!netlink_capable(skb, CAP_NET_ADMIN)))
                cmd = TIPC_CMD_NOT_NET_ADMIN;
        else
                cmd = req_userhdr->cmd;

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index f964d4c00ffb53457aa46b24f0225249c1d46b7c..352dfa4c39ee5dd0f1eeac20964a5ae96a9e014a 100644 (file)
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -2363,7 +2363,7 @@ static int xfrm_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
        link = &xfrm_dispatch[type];
 
        /* All operations require privileges, even GET */
-       if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+       if (!netlink_net_capable(skb, CAP_NET_ADMIN))
                return -EPERM;
 
        if ((type == (XFRM_MSG_GETSA - XFRM_MSG_BASE) ||