From: Gabriel Krisman Bertazi <krisman@collabora.com>
Date: Thu, 22 Oct 2020 20:58:41 +0000 (-0400)
Subject: blk-cgroup: Fix memleak on error path
X-Git-Tag: v5.4.76~37
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=f77756ea6641fdb84301c75bcc7434715028628c;p=users%2Fdwmw2%2Flinux.git

blk-cgroup: Fix memleak on error path

[ 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>
---

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 0c7addcd19859..a4793cfb68f28 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -861,6 +861,7 @@ 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;
 		}