From d3d2948f4353300e483e03be3f400dc07cf504ce Mon Sep 17 00:00:00 2001
From: Roland Kammerer <roland.kammerer@linbit.com>
Date: Tue, 29 Aug 2017 10:20:47 +0200
Subject: [PATCH] drbd: abort drbd_start_resync if there is no connection

This was found by a static analysis tool. While highly unlikely, be sure
to return without dereferencing the NULL pointer.

Reported-by: Shaobo <shaobo@cs.utah.edu>
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 drivers/block/drbd/drbd_worker.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index f0717a97a42a..03471b3fce86 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -1756,6 +1756,11 @@ void drbd_start_resync(struct drbd_device *device, enum drbd_conns side)
 		return;
 	}
 
+	if (!connection) {
+		drbd_err(device, "No connection to peer, aborting!\n");
+		return;
+	}
+
 	if (!test_bit(B_RS_H_DONE, &device->flags)) {
 		if (side == C_SYNC_TARGET) {
 			/* Since application IO was locked out during C_WF_BITMAP_T and