1 files changed, 38 insertions, 10 deletions

diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index c82d8e3e0d4f..88ae410b4113 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -355,16 +355,25 @@ static void export_stats_destroy(struct export_stats *stats)
 					    EXP_STATS_COUNTERS_NUM);
 }
 
-static void svc_export_put(struct kref *ref)
+static void svc_export_release(struct rcu_head *rcu_head)
 {
-	struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
-	path_put(&exp->ex_path);
-	auth_domain_put(exp->ex_client);
+	struct svc_export *exp = container_of(rcu_head, struct svc_export,
+			ex_rcu);
+
 	nfsd4_fslocs_free(&exp->ex_fslocs);
 	export_stats_destroy(exp->ex_stats);
 	kfree(exp->ex_stats);
 	kfree(exp->ex_uuid);
-	kfree_rcu(exp, ex_rcu);
+	kfree(exp);
+}
+
+static void svc_export_put(struct kref *ref)
+{
+	struct svc_export *exp = container_of(ref, struct svc_export, h.ref);
+
+	path_put(&exp->ex_path);
+	auth_domain_put(exp->ex_client);
+	call_rcu(&exp->ex_rcu, svc_export_release);
 }
 
 static int svc_export_upcall(struct cache_detail *cd, struct cache_head *h)
@@ -1078,12 +1087,14 @@ static struct svc_export *exp_find(struct cache_detail *cd,
  * check_nfsd_access - check if access to export is allowed.
  * @exp: svc_export that is being accessed.
  * @rqstp: svc_rqst attempting to access @exp (will be NULL for LOCALIO).
+ * @may_bypass_gss: reduce strictness of authorization check
  *
  * Return values:
  *   %nfs_ok if access is granted, or
  *   %nfserr_wrongsec if access is denied
  */
-__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp)
+__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp,
+			 bool may_bypass_gss)
 {
 	struct exp_flavor_info *f, *end = exp->ex_flavors + exp->ex_nflavors;
 	struct svc_xprt *xprt;
@@ -1113,7 +1124,8 @@ __be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp)
 		    test_bit(XPT_PEER_AUTH, &xprt->xpt_flags))
 			goto ok;
 	}
-	goto denied;
+	if (!may_bypass_gss)
+		goto denied;
 
 ok:
 	/* legacy gss-only clients are always OK: */
@@ -1140,6 +1152,23 @@ ok:
 	if (nfsd4_spo_must_allow(rqstp))
 		return nfs_ok;
 
+	/* Some calls may be processed without authentication
+	 * on GSS exports. For example NFS2/3 calls on root
+	 * directory, see section 2.3.2 of rfc 2623.
+	 * For "may_bypass_gss" check that export has really
+	 * enabled some flavor with authentication (GSS or any
+	 * other) and also check that the used auth flavor is
+	 * without authentication (none or sys).
+	 */
+	if (may_bypass_gss && (
+	     rqstp->rq_cred.cr_flavor == RPC_AUTH_NULL ||
+	     rqstp->rq_cred.cr_flavor == RPC_AUTH_UNIX)) {
+		for (f = exp->ex_flavors; f < end; f++) {
+			if (f->pseudoflavor >= RPC_AUTH_DES)
+				return 0;
+		}
+	}
+
 denied:
 	return nfserr_wrongsec;
 }
@@ -1406,10 +1435,9 @@ static int e_show(struct seq_file *m, void *p)
 		return 0;
 	}
 
-	exp_get(exp);
-	if (cache_check(cd, &exp->h, NULL))
+	if (cache_check_rcu(cd, &exp->h, NULL))
 		return 0;
-	exp_put(exp);
+
 	return svc_export_show(m, cd, cp);
 }