md: fix problems with freeing private data after ->run failure.

If ->run() fails, it can either free the data structures it
allocated, or leave that task to ->free() which will be called
on failures.

However:
  md.c calls ->free() even if ->private_data is NULL, which
     causes problems in some personalities.
  raid0.c frees the data, but doesn't clear ->private_data,
     which will become a problem when we fix md.c

So better fix both these issues at once.

Reported-by: Richard W.M. Jones <rjones@redhat.com>
Fixes: 5aa61f427e4979be733e4847b9199ff9cc48a47e
URL: https://bugzilla.kernel.org/show_bug.cgi?id=94381
Signed-off-by: NeilBrown <neilb@suse.de>

2 files changed, 2 insertions, 3 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index cadf9cc02b25..717daad71fb1 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -5080,7 +5080,8 @@ int md_run(struct mddev *mddev)
         }
         if (err) {
                 mddev_detach(mddev);
-                pers->free(mddev, mddev->private);
+                if (mddev->private)
+                        pers->free(mddev, mddev->private);
                 module_put(pers->owner);
                 bitmap_destroy(mddev);
                 return err;
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index a13f738a7b39..3ed9f42ddca6 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -467,8 +467,6 @@ static int raid0_run(struct mddev *mddev)
         dump_zones(mddev);
 
         ret = md_integrity_register(mddev);
-        if (ret)
-                raid0_free(mddev, conf);
 
         return ret;
 }