From 5d8817833c7609c24da9a92f71c53caa9c1424eb Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Thu, 28 Jul 2016 09:06:34 -0700 Subject: [PATCH] MD: fix null pointer deference The md device might not have personality (for example, ddf raid array). The issue is introduced by 8430e7e0af9a15(md: disconnect device from personality before trying to remove it) Reported-by: kernel test robot Signed-off-by: Shaohua Li --- drivers/md/md.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/md/md.c b/drivers/md/md.c index f77cad854044..c059f17b44d2 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -2595,8 +2595,10 @@ state_store(struct md_rdev *rdev, const char *buf, size_t len) else err = -EBUSY; } else if (cmd_match(buf, "remove")) { - clear_bit(Blocked, &rdev->flags); - remove_and_add_spares(rdev->mddev, rdev); + if (rdev->mddev->pers) { + clear_bit(Blocked, &rdev->flags); + remove_and_add_spares(rdev->mddev, rdev); + } if (rdev->raid_disk >= 0) err = -EBUSY; else {