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 3dc7c0b4adcbb59e8f1afabba91c72b608d680a0..a7217caea699d287cf0d8bf5e3269fa3c74d70f9 100644 (file)
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -878,6 +878,7 @@ 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;
                }