From: Ming Lei <ming.lei@redhat.com>
Date: Fri, 23 Sep 2022 19:51:19 +0800
Subject: cgroup: cgroup_get_from_id() must check the looked-up kn is a
directory
Git-commit: df02452f3df069a59bc9e69c84435bf115cb6e37
Patch-mainline: v6.0-rc7
References: bsc#1203906
cgroup has to be one kernfs dir, otherwise kernel panic is caused,
especially cgroup id is provide from userspace.
Reported-by: Marco Patalano <mpatalan@redhat.com>
Fixes: 6b658c4863c1 ("scsi: cgroup: Add cgroup_get_from_id()")
Cc: Muneendra <muneendra.kumar@broadcom.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
Cc: stable@vger.kernel.org # v5.14+
Signed-off-by: Tejun Heo <tj@kernel.org>
[mkoutny: adjust context]
Acked-by: Michal Koutný <mkoutny@suse.com>
---
kernel/cgroup/cgroup.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -6018,9 +6018,13 @@ struct cgroup *cgroup_get_from_id(u64 id
if (!kn)
goto out_unlock;
+ if (kernfs_type(kn) != KERNFS_DIR)
+ goto put;
+
cgrp = kn->priv;
if (cgroup_is_dead(cgrp) || !cgroup_tryget(cgrp))
cgrp = NULL;
+put:
kernfs_put(kn);
out_unlock:
mutex_unlock(&cgroup_mutex);