dm thin metadata: Avoid returning cmd->bm wild pointer on error

commit 219403d7e56f9b716ad80ab87db85d29547ee73e upstream.

Maybe __create_persistent_data_objects() caller will use PTR_ERR as a
pointer, it will lead to some strange things.

Signed-off-by: Ye Bin <yebin10@huawei.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/md/dm-thin-metadata.c b/drivers/md/dm-thin-metadata.c
index d20f402..b5bf2ec 100644 (file)
--- a/drivers/md/dm-thin-metadata.c
+++ b/drivers/md/dm-thin-metadata.c
@@ -700,12 +700,16 @@ static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool f
                                          THIN_MAX_CONCURRENT_LOCKS);
        if (IS_ERR(pmd->bm)) {
                DMERR("could not create block manager");
-               return PTR_ERR(pmd->bm);
+               r = PTR_ERR(pmd->bm);
+               pmd->bm = NULL;
+               return r;
        }
 
        r = __open_or_format_metadata(pmd, format_device);
-       if (r)
+       if (r) {
                dm_block_manager_destroy(pmd->bm);
+               pmd->bm = NULL;
+       }
 
        return r;
 }