From 998b1925bd6d19b2b32141b92de66b77027130a0 Mon Sep 17 00:00:00 2001
From: Kefu Chai <kchai@redhat.com>
Date: Wed, 27 Mar 2019 00:02:01 +0800
Subject: [PATCH] mon/MonClient: do not dereference auth_supported.end()

if we are unable to find a supported method in allowed_methods, we will
dereference `auth_supported.end()` for searching it in desperation.

Reported-by: xie xingguo <xie.xingguo@zte.com.cn>
Signed-off-by: Kefu Chai <kchai@redhat.com>
---
 src/mon/MonClient.cc | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/src/mon/MonClient.cc b/src/mon/MonClient.cc
index 2c36868c13c56..1ce68eb19a611 100644
--- a/src/mon/MonClient.cc
+++ b/src/mon/MonClient.cc
@@ -12,6 +12,8 @@
  * 
  */
 
+#include <algorithm>
+#include <iterator>
 #include <random>
 #include <boost/range/adaptor/map.hpp>
 #include <boost/range/adaptor/filtered.hpp>
@@ -1639,14 +1641,8 @@ int MonConnection::handle_auth_bad_method(
   auto p = std::find(auth_supported.begin(), auth_supported.end(),
 		     old_auth_method);
   assert(p != auth_supported.end());
-
-  while (p != auth_supported.end()) {
-    ++p;
-    if (std::find(allowed_methods.begin(), allowed_methods.end(), *p) !=
-	allowed_methods.end()) {
-      break;
-    }
-  }
+  p = std::find_first_of(std::next(p), auth_supported.end(),
+			 allowed_methods.begin(), allowed_methods.end());
   if (p == auth_supported.end()) {
     lderr(cct) << __func__ << " server allowed_methods " << allowed_methods
 	       << " but i only support " << auth_supported << dendl;
-- 
2.39.5