From 5d42cbdfd7ab79b42e4fab930ae40f198fb87412 Mon Sep 17 00:00:00 2001
From: John Spray <john.spray@redhat.com>
Date: Mon, 6 Feb 2017 11:31:44 +0000
Subject: [PATCH] mds: fix bad iterator dereference reported by coverity

Fixes: http://tracker.ceph.com/issues/18830
Signed-off-by: John Spray <john.spray@redhat.com>
---
 src/mds/Locker.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/mds/Locker.cc b/src/mds/Locker.cc
index 95a1f24d08c..79da56f43b2 100644
--- a/src/mds/Locker.cc
+++ b/src/mds/Locker.cc
@@ -471,7 +471,7 @@ bool Locker::acquire_locks(MDRequestRef& mdr,
     }
     
     // hose any stray locks
-    if (*existing == *p) {
+    if (existing != mdr->locks.end() && *existing == *p) {
       assert(need_wrlock || need_remote_wrlock);
       SimpleLock *lock = *existing;
       if (mdr->wrlocks.count(lock)) {
-- 
2.47.3