From: Ye Bin <yebin10@huawei.com>
Date: Tue, 1 Sep 2020 06:25:42 +0000 (+0800)
Subject: dm cache metadata: Avoid returning cmd->bm wild pointer on error
X-Git-Tag: v4.4.236~20
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=caf38213c01611c11aaa0ec7d2b7433a38552752;p=thirdparty%2Fkernel%2Fstable.git

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

commit d16ff19e69ab57e08bf908faaacbceaf660249de 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-cache-metadata.c b/drivers/md/dm-cache-metadata.c
index 905badc6cb179..216675b96e029 100644
--- a/drivers/md/dm-cache-metadata.c
+++ b/drivers/md/dm-cache-metadata.c
@@ -501,12 +501,16 @@ static int __create_persistent_data_objects(struct dm_cache_metadata *cmd,
 					  CACHE_MAX_CONCURRENT_LOCKS);
 	if (IS_ERR(cmd->bm)) {
 		DMERR("could not create block manager");
-		return PTR_ERR(cmd->bm);
+		r = PTR_ERR(cmd->bm);
+		cmd->bm = NULL;
+		return r;
 	}
 
 	r = __open_or_format_metadata(cmd, may_format_device);
-	if (r)
+	if (r) {
 		dm_block_manager_destroy(cmd->bm);
+		cmd->bm = NULL;
+	}
 
 	return r;
 }