libceph: Fix NULL pointer dereference in auth client code
A malicious monitor can craft an auth reply message that could cause a
NULL function pointer dereference in the client's kernel.
To prevent this, the auth_none protocol handler needs an empty
ceph_auth_client_ops->build_request() function.
CVE-2013-1059
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reported-by: Chanam Park <chanam.park@hkpco.kr>
Reviewed-by: Seth Arnold <seth.arnold@canonical.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Cc: stable@vger.kernel.org
diff --git a/net/ceph/auth_none.c b/net/ceph/auth_none.c
index 925ca58..8c93fa8 100644
--- a/net/ceph/auth_none.c
+++ b/net/ceph/auth_none.c
@@ -39,6 +39,11 @@
return xi->starting;
}
+static int build_request(struct ceph_auth_client *ac, void *buf, void *end)
+{
+ return 0;
+}
+
/*
* the generic auth code decode the global_id, and we carry no actual
* authenticate state, so nothing happens here.
@@ -106,6 +111,7 @@
.destroy = destroy,
.is_authenticated = is_authenticated,
.should_authenticate = should_authenticate,
+ .build_request = build_request,
.handle_reply = handle_reply,
.create_authorizer = ceph_auth_none_create_authorizer,
.destroy_authorizer = ceph_auth_none_destroy_authorizer,