[PATCH] sunrpc: fix code that makes auth_gss send destroy_cred message

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



There's a bit of a chicken and egg problem when it comes to destroying
auth_gss credentials. When we destroy the last instance of a GSSAPI RPC
credential, we should send a NULL RPC call with a GSS procedure of
RPCSEC_GSS_DESTROY to hint to the server that it can destroy those
creds.

This isn't happening because we're setting clearing the uptodate bit on
the credentials and then setting the operations to the gss_nullops. When
we go to do the RPC call, we try to refresh the creds. That fails with
-EACCES and the call fails.

Fix this by not clearing the UPTODATE bit for the credentials and adding
a new crdestroy op for gss_nullops that just tears down the cred without
trying to destroy the context.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
 net/sunrpc/auth_gss/auth_gss.c |   23 ++++++++++++++++-------
 1 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index 853a414..e22fb45 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -693,7 +693,7 @@ gss_destroying_context(struct rpc_cred *cred)
 	struct rpc_task *task;
 
 	if (gss_cred->gc_ctx == NULL ||
-	    test_and_clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
+	    test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) == 0)
 		return 0;
 
 	gss_cred->gc_ctx->gc_proc = RPC_GSS_PROC_DESTROY;
@@ -757,14 +757,14 @@ gss_free_cred_callback(struct rcu_head *head)
 }
 
 static void
-gss_destroy_cred(struct rpc_cred *cred)
+gss_destroy_nullcred(struct rpc_cred *cred)
 {
-	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
-	struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
+	struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
+						 gc_base);
+	struct gss_auth *gss_auth = container_of(cred->cr_auth,
+						 struct gss_auth, rpc_auth);
 	struct gss_cl_ctx *ctx = gss_cred->gc_ctx;
 
-	if (gss_destroying_context(cred))
-		return;
 	rcu_assign_pointer(gss_cred->gc_ctx, NULL);
 	call_rcu(&cred->cr_rcu, gss_free_cred_callback);
 	if (ctx)
@@ -772,6 +772,15 @@ gss_destroy_cred(struct rpc_cred *cred)
 	kref_put(&gss_auth->kref, gss_free_callback);
 }
 
+static void
+gss_destroy_cred(struct rpc_cred *cred)
+{
+
+	if (gss_destroying_context(cred))
+		return;
+	gss_destroy_nullcred(cred);
+}
+
 /*
  * Lookup RPCSEC_GSS cred for the current process
  */
@@ -1324,7 +1333,7 @@ static const struct rpc_credops gss_credops = {
 
 static const struct rpc_credops gss_nullops = {
 	.cr_name	= "AUTH_GSS",
-	.crdestroy	= gss_destroy_cred,
+	.crdestroy	= gss_destroy_nullcred,
 	.crbind		= rpcauth_generic_bind_cred,
 	.crmatch	= gss_match,
 	.crmarshal	= gss_marshal,
-- 
1.5.5.1

--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Filesystem Development]     [Linux USB Development]     [Linux Media Development]     [Video for Linux]     [Linux NILFS]     [Linux Audio Users]     [Yosemite Info]     [Linux SCSI]

  Powered by Linux