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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Tejun Heo <tj@kernel.org>,
        Gabriel Krisman Bertazi <krisman@collabora.com>,
        Jens Axboe <axboe@kernel.dk>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.9 085/133] blk-cgroup: Fix memleak on error path
Date:   Mon,  9 Nov 2020 13:55:47 +0100
Message-Id: <20201109125034.801043377@linuxfoundation.org>
In-Reply-To: <20201109125030.706496283@linuxfoundation.org>
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From: Gabriel Krisman Bertazi <krisman@collabora.com>

[ 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>
---
 block/blk-cgroup.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index c195365c98172..7b2df042220d4 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -654,6 +654,7 @@ 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;
 		}
 
-- 
2.27.0