[IPSEC]: Fix potential dst leak in xfrm_lookup

If we get an error during the actual policy lookup we don't free the
original dst while the caller expects us to always free the original
dst in case of error.

This patch fixes that.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 3 deletions

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 9a4cf2e45a15..b91b16671c1e 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1318,8 +1318,9 @@ restart:
 
         if (sk && sk->sk_policy[XFRM_POLICY_OUT]) {
                 policy = xfrm_sk_policy_lookup(sk, XFRM_POLICY_OUT, fl);
+                err = PTR_ERR(policy);
                 if (IS_ERR(policy))
-                        return PTR_ERR(policy);
+                        goto dropdst;
         }
 
         if (!policy) {
@@ -1330,8 +1331,9 @@ restart:
 
                 policy = flow_cache_lookup(fl, dst_orig->ops->family,
                                            dir, xfrm_policy_lookup);
+                err = PTR_ERR(policy);
                 if (IS_ERR(policy))
-                        return PTR_ERR(policy);
+                        goto dropdst;
         }
 
         if (!policy)
@@ -1501,8 +1503,9 @@ restart:
         return 0;
 
 error:
-        dst_release(dst_orig);
         xfrm_pols_put(pols, npols);
+dropdst:
+        dst_release(dst_orig);
         *dst_p = NULL;
         return err;
 }