From 28e538a3093833cbac3e28dd511a8b74629d737a Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Mon, 6 Feb 2023 16:02:01 +0100
Subject: [PATCH] blk-cgroup: fix freeing NULL blkg in blkg_create
new_blkg can be NULL if the caller didn't pass in a pre-allocated blkg.
Don't try to free it in that case.
Fixes: 27b642b07a4a ("blk-cgroup: simplify blkg freeing from initialization failure paths")
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20230206150201.3438972-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
block/blk-cgroup.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 8faeca6022be..c46778d1f3c2 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -383,7 +383,8 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, struct gendisk *disk,
err_put_css:
css_put(&blkcg->css);
err_free_blkg:
- blkg_free(new_blkg);
+ if (new_blkg)
+ blkg_free(new_blkg);
return ERR_PTR(ret);
}