From 43f7bbe9ec476437d0117007e70adefeb5765cec Mon Sep 17 00:00:00 2001
From: Gabriel Krisman Bertazi <krisman@collabora.com>
Date: Thu, 22 Oct 2020 16:58:41 -0400
Subject: [PATCH 2245/2944] blk-cgroup: Fix memleak on error path

task #28557799

[ Upstream commit 52abfcbd57eefdd54737fc8c2dc79d8f46d4a3e5 ]

If new_blkg allocation raced with blk_policy change and
blkg_lookup_check fails, new_blkg is leaked.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
---
 block/blk-cgroup.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index abdbc8f..638c64a 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -907,6 +907,7 @@ int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
 		blkg = blkg_lookup_check(pos, pol, q);
 		if (IS_ERR(blkg)) {
 			ret = PTR_ERR(blkg);
+			blkg_free(new_blkg);
 			goto fail_unlock;
 		}
 
-- 
1.8.3.1