msg/Message: fix possible null deref

cct may be null

CID 716930: Dereference after null check (FORWARD_NULL)
At (11): Dereferencing null pointer "cct".

Signed-off-by: Sage Weil <sage@inktank.com>

diff --git a/src/msg/Message.cc b/src/msg/Message.cc
index 7046dd257b2ff95f396739891e98d2728f912692..0c5a185665392bde09112b3c843cb39b81972e2a 100644 (file)
--- a/src/msg/Message.cc
+++ b/src/msg/Message.cc
@@ -615,12 +615,14 @@ Message *decode_message(CephContext *cct, ceph_msg_header& header, ceph_msg_foot
   // it against compat_version.
   if (m->get_header().version &&
       m->get_header().version < header.compat_version) {
-    ldout(cct, 0) << "will not decode message of type " << type
-                 << " version " << header.version
-                 << " because compat_version " << header.compat_version
-                 << " > supported version " << m->get_header().version << dendl;
-    if (cct->_conf->ms_die_on_bad_msg)
-      assert(0);
+    if (cct) {
+      ldout(cct, 0) << "will not decode message of type " << type
+                   << " version " << header.version
+                   << " because compat_version " << header.compat_version
+                   << " > supported version " << m->get_header().version << dendl;
+      if (cct->_conf->ms_die_on_bad_msg)
+       assert(0);
+    }
     m->put();
     return 0;
   }