md: raid0: fix error return from create_stripe_zones.

Create_stripe_zones returns an error slightly differently to
raid0_run and to raid0_takeover_*.

The error returned used by the second was wrong and an error would
result in mddev->private being set to NULL and sooner or later a
crash.

So never return NULL, return ERR_PTR(err), not NULL from
create_stripe_zones.

This bug has been present since 2.6.35 so the fix is suitable
for any kernel since then.

Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 15c8d35..d9babda 100644 (file)
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -289,7 +289,7 @@ abort:
        kfree(conf->strip_zone);
        kfree(conf->devlist);
        kfree(conf);
-       *private_conf = NULL;
+       *private_conf = ERR_PTR(err);
        return err;
 }