[PATCH AUTOSEL 5.4 11/24] blk-cgroup: Fix memleak on error path

From: Sasha Levin
Date: Mon Nov 02 2020 - 20:24:10 EST


From: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>

[ 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@xxxxxxxxxx>
Signed-off-by: Gabriel Krisman Bertazi <krisman@xxxxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
block/blk-cgroup.c | 1 +
1 file changed, 1 insertion(+)

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;
}

--
2.27.0