md: Fix error paths if md_probe fails.

commit 9bbbca3a0ee09293108b67835c6bdf6196d7bcb3 upstream

md_probe can fail (e.g. alloc_disk could fail) without
returning an error (as it alway returns NULL).
So when we call mddev_find immediately afterwards, we need
to check that md_probe actually succeeded.  This means checking
that mdev->gendisk is non-NULL.

Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index ba34990a6b50f9db1913ad13f55706e89f0299d1..94e5711c7cc47f82a04080b4c35fb9632dd247d0 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3804,8 +3804,10 @@ static void autorun_devices(int part)
 
                md_probe(dev, NULL, NULL);
                mddev = mddev_find(dev);
-               if (!mddev) {
-                       printk(KERN_ERR 
+               if (!mddev || !mddev->gendisk) {
+                       if (mddev)
+                               mddev_put(mddev);
+                       printk(KERN_ERR
                                "md: cannot allocate memory for md drive.\n");
                        break;
                }