[IPSEC]: xfrm_policy delete security check misplaced

The security hooks to check permissions to remove an xfrm_policy were
actually done after the policy was removed.  Since the unlinking and
deletion are done in xfrm_policy_by* functions this moves the hooks
inside those 2 functions.  There we have all the information needed to
do the security check and it can be done before the deletion.  Since
auditing requires the result of that security check err has to be passed
back and forth from the xfrm_policy_by* functions.

This patch also fixes a bug where a deletion that failed the security
check could cause improper accounting on the xfrm_policy
(xfrm_get_policy didn't have a put on the exit path for the hold taken
by xfrm_policy_by*)

It also fixes the return code when no policy is found in
xfrm_add_pol_expire.  In old code (at least back in the 2.6.18 days) err
wasn't used before the return when no policy is found and so the
initialization would cause err to be ENOENT.  But since err has since
been used above when we don't get a policy back from the xfrm_policy_by*
function we would always return 0 instead of the intended ENOENT.  Also
fixed some white space damage in the same area.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Venkat Yekkirala <vyekkirala@trustedcs.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/xfrm.h b/include/net/xfrm.h
index 92a1fc46ea593c6cfb2f0529568c4aa2e83a7c48..5a00aa85b756fe46a3297ace099e8520012f1d7a 100644 (file)
--- a/include/net/xfrm.h
+++ b/include/net/xfrm.h
@@ -988,8 +988,9 @@ extern int xfrm_policy_walk(u8 type, int (*func)(struct xfrm_policy *, int, int,
 int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl);
 struct xfrm_policy *xfrm_policy_bysel_ctx(u8 type, int dir,
                                          struct xfrm_selector *sel,
-                                         struct xfrm_sec_ctx *ctx, int delete);
-struct xfrm_policy *xfrm_policy_byid(u8, int dir, u32 id, int delete);
+                                         struct xfrm_sec_ctx *ctx, int delete,
+                                         int *err);
+struct xfrm_policy *xfrm_policy_byid(u8, int dir, u32 id, int delete, int *err);
 void xfrm_policy_flush(u8 type, struct xfrm_audit *audit_info);
 u32 xfrm_get_acqseq(void);
 void xfrm_alloc_spi(struct xfrm_state *x, __be32 minspi, __be32 maxspi);

diff --git a/net/key/af_key.c b/net/key/af_key.c
index 1c58204d767e6ad460775b13985833dcbf3d5f95..3542435e9d40d1f9c7a978bab6ac7bbc89fb5706 100644 (file)
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -2294,14 +2294,12 @@ static int pfkey_spddelete(struct sock *sk, struct sk_buff *skb, struct sadb_msg
        }
 
        xp = xfrm_policy_bysel_ctx(XFRM_POLICY_TYPE_MAIN, pol->sadb_x_policy_dir-1,
-                                  &sel, tmp.security, 1);
+                                  &sel, tmp.security, 1, &err);
        security_xfrm_policy_free(&tmp);
 
        if (xp == NULL)
                return -ENOENT;
 
-       err = security_xfrm_policy_delete(xp);
-
        xfrm_audit_log(audit_get_loginuid(current->audit_context), 0,
                       AUDIT_MAC_IPSEC_DELSPD, err ? 0 : 1, xp, NULL);
 
@@ -2552,7 +2550,7 @@ static int pfkey_spdget(struct sock *sk, struct sk_buff *skb, struct sadb_msg *h
                return -EINVAL;
 
        xp = xfrm_policy_byid(XFRM_POLICY_TYPE_MAIN, dir, pol->sadb_x_policy_id,
-                             hdr->sadb_msg_type == SADB_X_SPDDELETE2);
+                             hdr->sadb_msg_type == SADB_X_SPDDELETE2, &err);
        if (xp == NULL)
                return -ENOENT;
 

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 946b715db5ec8c708287d8d5ae51a2eb4d77ab8e..0c3a70ac507545e6afef5d282c0460560e0ecdb5 100644 (file)
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -735,12 +735,14 @@ EXPORT_SYMBOL(xfrm_policy_insert);
 
 struct xfrm_policy *xfrm_policy_bysel_ctx(u8 type, int dir,
                                          struct xfrm_selector *sel,
-                                         struct xfrm_sec_ctx *ctx, int delete)
+                                         struct xfrm_sec_ctx *ctx, int delete,
+                                         int *err)
 {
        struct xfrm_policy *pol, *ret;
        struct hlist_head *chain;
        struct hlist_node *entry;
 
+       *err = 0;
        write_lock_bh(&xfrm_policy_lock);
        chain = policy_hash_bysel(sel, sel->family, dir);
        ret = NULL;
@@ -750,6 +752,11 @@ struct xfrm_policy *xfrm_policy_bysel_ctx(u8 type, int dir,
                    xfrm_sec_ctx_match(ctx, pol->security)) {
                        xfrm_pol_hold(pol);
                        if (delete) {
+                               *err = security_xfrm_policy_delete(pol);
+                               if (*err) {
+                                       write_unlock_bh(&xfrm_policy_lock);
+                                       return pol;
+                               }
                                hlist_del(&pol->bydst);
                                hlist_del(&pol->byidx);
                                xfrm_policy_count[dir]--;
@@ -768,12 +775,14 @@ struct xfrm_policy *xfrm_policy_bysel_ctx(u8 type, int dir,
 }
 EXPORT_SYMBOL(xfrm_policy_bysel_ctx);
 
-struct xfrm_policy *xfrm_policy_byid(u8 type, int dir, u32 id, int delete)
+struct xfrm_policy *xfrm_policy_byid(u8 type, int dir, u32 id, int delete,
+                                    int *err)
 {
        struct xfrm_policy *pol, *ret;
        struct hlist_head *chain;
        struct hlist_node *entry;
 
+       *err = 0;
        write_lock_bh(&xfrm_policy_lock);
        chain = xfrm_policy_byidx + idx_hash(id);
        ret = NULL;
@@ -781,6 +790,11 @@ struct xfrm_policy *xfrm_policy_byid(u8 type, int dir, u32 id, int delete)
                if (pol->type == type && pol->index == id) {
                        xfrm_pol_hold(pol);
                        if (delete) {
+                               *err = security_xfrm_policy_delete(pol);
+                               if (*err) {
+                                       write_unlock_bh(&xfrm_policy_lock);
+                                       return pol;
+                               }
                                hlist_del(&pol->bydst);
                                hlist_del(&pol->byidx);
                                xfrm_policy_count[dir]--;

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 956cfe0ff7f82b91067fae393ae9085538ad5972..30c244bbd8ac65d1251362d375898e2a04b36d41 100644 (file)
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1254,7 +1254,7 @@ static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh,
                return err;
 
        if (p->index)
-               xp = xfrm_policy_byid(type, p->dir, p->index, delete);
+               xp = xfrm_policy_byid(type, p->dir, p->index, delete, &err);
        else {
                struct rtattr *rt = xfrma[XFRMA_SEC_CTX-1];
                struct xfrm_policy tmp;
@@ -1270,7 +1270,8 @@ static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh,
                        if ((err = security_xfrm_policy_alloc(&tmp, uctx)))
                                return err;
                }
-               xp = xfrm_policy_bysel_ctx(type, p->dir, &p->sel, tmp.security, delete);
+               xp = xfrm_policy_bysel_ctx(type, p->dir, &p->sel, tmp.security,
+                                          delete, &err);
                security_xfrm_policy_free(&tmp);
        }
        if (xp == NULL)
@@ -1288,8 +1289,6 @@ static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh,
                                              MSG_DONTWAIT);
                }
        } else {
-               err = security_xfrm_policy_delete(xp);
-
                xfrm_audit_log(NETLINK_CB(skb).loginuid, NETLINK_CB(skb).sid,
                               AUDIT_MAC_IPSEC_DELSPD, err ? 0 : 1, xp, NULL);
 
@@ -1303,9 +1302,8 @@ static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh,
                km_policy_notify(xp, p->dir, &c);
        }
 
-       xfrm_pol_put(xp);
-
 out:
+       xfrm_pol_put(xp);
        return err;
 }
 
@@ -1502,7 +1500,7 @@ static int xfrm_add_pol_expire(struct sk_buff *skb, struct nlmsghdr *nlh,
                return err;
 
        if (p->index)
-               xp = xfrm_policy_byid(type, p->dir, p->index, 0);
+               xp = xfrm_policy_byid(type, p->dir, p->index, 0, &err);
        else {
                struct rtattr *rt = xfrma[XFRMA_SEC_CTX-1];
                struct xfrm_policy tmp;
@@ -1518,13 +1516,14 @@ static int xfrm_add_pol_expire(struct sk_buff *skb, struct nlmsghdr *nlh,
                        if ((err = security_xfrm_policy_alloc(&tmp, uctx)))
                                return err;
                }
-               xp = xfrm_policy_bysel_ctx(type, p->dir, &p->sel, tmp.security, 0);
+               xp = xfrm_policy_bysel_ctx(type, p->dir, &p->sel, tmp.security,
+                                          0, &err);
                security_xfrm_policy_free(&tmp);
        }
 
        if (xp == NULL)
-               return err;
-                                                                                       read_lock(&xp->lock);
+               return -ENOENT;
+       read_lock(&xp->lock);
        if (xp->dead) {
                read_unlock(&xp->lock);
                goto out;