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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Gabriel Krisman Bertazi <krisman@collabora.com>,
        Tejun Heo <tj@kernel.org>, Jens Axboe <axboe@kernel.dk>,
        Sasha Levin <sashal@kernel.org>, cgroups@vger.kernel.org,
        linux-block@vger.kernel.org
Subject: [PATCH AUTOSEL 4.19 05/11] blk-cgroup: Fix memleak on error path
Date:   Mon,  2 Nov 2020 20:20:33 -0500
Message-Id: <20201103012039.183672-5-sashal@kernel.org>
In-Reply-To: <20201103012039.183672-1-sashal@kernel.org>
References: <20201103012039.183672-1-sashal@kernel.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 a06547fe6f6b4..51fc803c999d7 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -882,6 +882,7 @@ 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