Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

Steffen Klassert says:

====================
pull request (net): ipsec 2017-04-19

Two fixes for af_key:

1) Add a lock to key dump to prevent a NULL pointer dereference.
   From Yuejie Shi.

2) Fix slab-out-of-bounds in parse_ipsecrequests.
   From Herbert Xu.

Please pull or let me know if there are problems.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 64 insertions, 29 deletions

diff --git a/net/key/af_key.c b/net/key/af_key.c
index c6252ed42c1d..be8cecc65002 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -63,8 +63,13 @@ struct pfkey_sock {
                 } u;
                 struct sk_buff  *skb;
         } dump;
+        struct mutex dump_lock;
 };
 
+static int parse_sockaddr_pair(struct sockaddr *sa, int ext_len,
+                               xfrm_address_t *saddr, xfrm_address_t *daddr,
+                               u16 *family);
+
 static inline struct pfkey_sock *pfkey_sk(struct sock *sk)
 {
         return (struct pfkey_sock *)sk;
@@ -139,6 +144,7 @@ static int pfkey_create(struct net *net, struct socket *sock, int protocol,
 {
         struct netns_pfkey *net_pfkey = net_generic(net, pfkey_net_id);
         struct sock *sk;
+        struct pfkey_sock *pfk;
         int err;
 
         if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
@@ -153,6 +159,9 @@ static int pfkey_create(struct net *net, struct socket *sock, int protocol,
         if (sk == NULL)
                 goto out;
 
+        pfk = pfkey_sk(sk);
+        mutex_init(&pfk->dump_lock);
+
         sock->ops = &pfkey_ops;
         sock_init_data(sock, sk);
 
@@ -281,13 +290,23 @@ static int pfkey_do_dump(struct pfkey_sock *pfk)
         struct sadb_msg *hdr;
         int rc;
 
+        mutex_lock(&pfk->dump_lock);
+        if (!pfk->dump.dump) {
+                rc = 0;
+                goto out;
+        }
+
         rc = pfk->dump.dump(pfk);
-        if (rc == -ENOBUFS)
-                return 0;
+        if (rc == -ENOBUFS) {
+                rc = 0;
+                goto out;
+        }
 
         if (pfk->dump.skb) {
-                if (!pfkey_can_dump(&pfk->sk))
-                        return 0;
+                if (!pfkey_can_dump(&pfk->sk)) {
+                        rc = 0;
+                        goto out;
+                }
 
                 hdr = (struct sadb_msg *) pfk->dump.skb->data;
                 hdr->sadb_msg_seq = 0;
@@ -298,6 +317,9 @@ static int pfkey_do_dump(struct pfkey_sock *pfk)
         }
 
         pfkey_terminate_dump(pfk);
+
+out:
+        mutex_unlock(&pfk->dump_lock);
         return rc;
 }
 
@@ -1793,19 +1815,26 @@ static int pfkey_dump(struct sock *sk, struct sk_buff *skb, const struct sadb_ms
         struct xfrm_address_filter *filter = NULL;
         struct pfkey_sock *pfk = pfkey_sk(sk);
 
-        if (pfk->dump.dump != NULL)
+        mutex_lock(&pfk->dump_lock);
+        if (pfk->dump.dump != NULL) {
+                mutex_unlock(&pfk->dump_lock);
                 return -EBUSY;
+        }
 
         proto = pfkey_satype2proto(hdr->sadb_msg_satype);
-        if (proto == 0)
+        if (proto == 0) {
+                mutex_unlock(&pfk->dump_lock);
                 return -EINVAL;
+        }
 
         if (ext_hdrs[SADB_X_EXT_FILTER - 1]) {
                 struct sadb_x_filter *xfilter = ext_hdrs[SADB_X_EXT_FILTER - 1];
 
                 filter = kmalloc(sizeof(*filter), GFP_KERNEL);
-                if (filter == NULL)
+                if (filter == NULL) {
+                        mutex_unlock(&pfk->dump_lock);
                         return -ENOMEM;
+                }
 
                 memcpy(&filter->saddr, &xfilter->sadb_x_filter_saddr,
                        sizeof(xfrm_address_t));
@@ -1821,6 +1850,7 @@ static int pfkey_dump(struct sock *sk, struct sk_buff *skb, const struct sadb_ms
         pfk->dump.dump = pfkey_dump_sa;
         pfk->dump.done = pfkey_dump_sa_done;
         xfrm_state_walk_init(&pfk->dump.u.state, proto, filter);
+        mutex_unlock(&pfk->dump_lock);
 
         return pfkey_do_dump(pfk);
 }
@@ -1913,19 +1943,14 @@ parse_ipsecrequest(struct xfrm_policy *xp, struct sadb_x_ipsecrequest *rq)
 
         /* addresses present only in tunnel mode */
         if (t->mode == XFRM_MODE_TUNNEL) {
-                u8 *sa = (u8 *) (rq + 1);
-                int family, socklen;
+                int err;
 
-                family = pfkey_sockaddr_extract((struct sockaddr *)sa,
-                                                &t->saddr);
-                if (!family)
-                        return -EINVAL;
-
-                socklen = pfkey_sockaddr_len(family);
-                if (pfkey_sockaddr_extract((struct sockaddr *)(sa + socklen),
-                                           &t->id.daddr) != family)
-                        return -EINVAL;
-                t->encap_family = family;
+                err = parse_sockaddr_pair(
+                        (struct sockaddr *)(rq + 1),
+                        rq->sadb_x_ipsecrequest_len - sizeof(*rq),
+                        &t->saddr, &t->id.daddr, &t->encap_family);
+                if (err)
+                        return err;
         } else
                 t->encap_family = xp->family;
 
@@ -1945,7 +1970,11 @@ parse_ipsecrequests(struct xfrm_policy *xp, struct sadb_x_policy *pol)
         if (pol->sadb_x_policy_len * 8 < sizeof(struct sadb_x_policy))
                 return -EINVAL;
 
-        while (len >= sizeof(struct sadb_x_ipsecrequest)) {
+        while (len >= sizeof(*rq)) {
+                if (len < rq->sadb_x_ipsecrequest_len ||
+                    rq->sadb_x_ipsecrequest_len < sizeof(*rq))
+                        return -EINVAL;
+
                 if ((err = parse_ipsecrequest(xp, rq)) < 0)
                         return err;
                 len -= rq->sadb_x_ipsecrequest_len;
@@ -2408,7 +2437,6 @@ out:
         return err;
 }
 
-#ifdef CONFIG_NET_KEY_MIGRATE
 static int pfkey_sockaddr_pair_size(sa_family_t family)
 {
         return PFKEY_ALIGN8(pfkey_sockaddr_len(family) * 2);
@@ -2420,7 +2448,7 @@ static int parse_sockaddr_pair(struct sockaddr *sa, int ext_len,
 {
         int af, socklen;
 
-        if (ext_len < pfkey_sockaddr_pair_size(sa->sa_family))
+        if (ext_len < 2 || ext_len < pfkey_sockaddr_pair_size(sa->sa_family))
                 return -EINVAL;
 
         af = pfkey_sockaddr_extract(sa, saddr);
@@ -2436,6 +2464,7 @@ static int parse_sockaddr_pair(struct sockaddr *sa, int ext_len,
         return 0;
 }
 
+#ifdef CONFIG_NET_KEY_MIGRATE
 static int ipsecrequests_to_migrate(struct sadb_x_ipsecrequest *rq1, int len,
                                     struct xfrm_migrate *m)
 {
@@ -2443,13 +2472,14 @@ static int ipsecrequests_to_migrate(struct sadb_x_ipsecrequest *rq1, int len,
         struct sadb_x_ipsecrequest *rq2;
         int mode;
 
-        if (len <= sizeof(struct sadb_x_ipsecrequest) ||
-            len < rq1->sadb_x_ipsecrequest_len)
+        if (len < sizeof(*rq1) ||
+            len < rq1->sadb_x_ipsecrequest_len ||
+            rq1->sadb_x_ipsecrequest_len < sizeof(*rq1))
                 return -EINVAL;
 
         /* old endoints */
         err = parse_sockaddr_pair((struct sockaddr *)(rq1 + 1),
-                                  rq1->sadb_x_ipsecrequest_len,
+                                  rq1->sadb_x_ipsecrequest_len - sizeof(*rq1),
                                   &m->old_saddr, &m->old_daddr,
                                   &m->old_family);
         if (err)
@@ -2458,13 +2488,14 @@ static int ipsecrequests_to_migrate(struct sadb_x_ipsecrequest *rq1, int len,
         rq2 = (struct sadb_x_ipsecrequest *)((u8 *)rq1 + rq1->sadb_x_ipsecrequest_len);
         len -= rq1->sadb_x_ipsecrequest_len;
 
-        if (len <= sizeof(struct sadb_x_ipsecrequest) ||
-            len < rq2->sadb_x_ipsecrequest_len)
+        if (len <= sizeof(*rq2) ||
+            len < rq2->sadb_x_ipsecrequest_len ||
+            rq2->sadb_x_ipsecrequest_len < sizeof(*rq2))
                 return -EINVAL;
 
         /* new endpoints */
         err = parse_sockaddr_pair((struct sockaddr *)(rq2 + 1),
-                                  rq2->sadb_x_ipsecrequest_len,
+                                  rq2->sadb_x_ipsecrequest_len - sizeof(*rq2),
                                   &m->new_saddr, &m->new_daddr,
                                   &m->new_family);
         if (err)
@@ -2679,14 +2710,18 @@ static int pfkey_spddump(struct sock *sk, struct sk_buff *skb, const struct sadb
 {
         struct pfkey_sock *pfk = pfkey_sk(sk);
 
-        if (pfk->dump.dump != NULL)
+        mutex_lock(&pfk->dump_lock);
+        if (pfk->dump.dump != NULL) {
+                mutex_unlock(&pfk->dump_lock);
                 return -EBUSY;
+        }
 
         pfk->dump.msg_version = hdr->sadb_msg_version;
         pfk->dump.msg_portid = hdr->sadb_msg_pid;
         pfk->dump.dump = pfkey_dump_sp;
         pfk->dump.done = pfkey_dump_sp_done;
         xfrm_policy_walk_init(&pfk->dump.u.policy, XFRM_POLICY_TYPE_MAIN);
+        mutex_unlock(&pfk->dump_lock);
 
         return pfkey_do_dump(pfk);
 }