From 033c0467dac4aa0eb64fc04a226da02f29e15c3b Mon Sep 17 00:00:00 2001
From: Michael Adam <obnox@samba.org>
Date: Fri, 20 May 2016 12:57:48 +0200
Subject: [PATCH] notifyd: prevent NULL deref segfault in
 notifyd_peer_destructor

It seems it could happen that p->db == NULL in the list
from notifyd_clean_peers_next(). This has been seen in
a ctdb cluster when an node-internal ctdb interface is
brought down.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11930

Signed-off-by: Michael Adam <obnox@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>

Autobuild-User(master): Volker Lendecke <vl@samba.org>
Autobuild-Date(master): Fri May 20 17:32:55 CEST 2016 on sn-devel-144

(cherry picked from commit 1c76746b637bc1867f85ba94786b89f22d1b0c32)
---
 source3/smbd/notifyd/notifyd.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/source3/smbd/notifyd/notifyd.c b/source3/smbd/notifyd/notifyd.c
index 49fb9c9..45b029b 100644
--- a/source3/smbd/notifyd/notifyd.c
+++ b/source3/smbd/notifyd/notifyd.c
@@ -1246,7 +1246,10 @@ static int notifyd_peer_destructor(struct notifyd_peer *p)
 	struct notifyd_state *state = p->state;
 	size_t i;
 
-	dbwrap_traverse_read(p->db, notifyd_db_del_syswatches, NULL, NULL);
+	if (p->db != NULL) {
+		dbwrap_traverse_read(p->db, notifyd_db_del_syswatches,
+				     NULL, NULL);
+	}
 
 	for (i = 0; i<state->num_peers; i++) {
 		if (p == state->peers[i]) {
-- 
2.5.5