From: Al Viro <viro@xxxxxxxxxxxxxxxxxx> [ Upstream commit 630faf81b3e61bcc90dc6d8b497800657d2752a5 ] the caller of ->get_tree() expects NULL left there on error... Reported-by: Thibaut Sautereau <thibaut@xxxxxxxxxxxx> Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- kernel/cgroup/cgroup.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 8be1da1ebd9a4..f23862fa15146 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -2119,11 +2119,12 @@ int cgroup_do_get_tree(struct fs_context *fc) nsdentry = kernfs_node_dentry(cgrp->kn, sb); dput(fc->root); - fc->root = nsdentry; if (IS_ERR(nsdentry)) { - ret = PTR_ERR(nsdentry); deactivate_locked_super(sb); + ret = PTR_ERR(nsdentry); + nsdentry = NULL; } + fc->root = nsdentry; } if (!ctx->kfc.new_sb_created) -- 2.20.1