From 0ba5879082544dc3aa13807087563b1258124b1e Mon Sep 17 00:00:00 2001
From: hank <redacted>
Date: Tue, 4 Sep 2012 10:23:45 +0800
Subject: [PATCH 1/1] drivers/md/raid1.c: fix NULL pointer bug in
 fix_read_error function

in fix_read_error function, the conf->mirrors[read_disk].rdev may
become NULL, as in this function, rdev->nr_pending may be zero, anyone
can delete it. So should check if it is NULL before use.

Signed-off-by: hank <redacted>
---
 drivers/md/raid1.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 611b5f7..fd8de28 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c

@@ -2005,7 +2005,7 @@ static void fix_read_error(struct r1conf *conf, int read_disk,
 		if (!success) {
 			/* Cannot read from anywhere - mark it bad */
 			struct md_rdev *rdev = conf->mirrors[read_disk].rdev;
-			if (!rdev_set_badblocks(rdev, sect, s, 0))
+			if (!rdev || !rdev_set_badblocks(rdev, sect, s, 0))
 				md_error(mddev, rdev);
 			break;
 		}