blk-cgroup: Fix memleak on error path

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>

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index f9b5561..f9389b7 100644 (file)
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -663,6 +663,7 @@ 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;
                }