The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
Possible dependencies:
df02452f3df0 ("cgroup: cgroup_get_from_id() must check the looked-up kn is a directory")
be288169712f ("cgroup: reduce dependency on cgroup_mutex")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From df02452f3df069a59bc9e69c84435bf115cb6e37 Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@xxxxxxxxxx>
Date: Fri, 23 Sep 2022 19:51:19 +0800
Subject: [PATCH] cgroup: cgroup_get_from_id() must check the looked-up kn is a
directory
cgroup has to be one kernfs dir, otherwise kernel panic is caused,
especially cgroup id is provide from userspace.
Reported-by: Marco Patalano <mpatalan@xxxxxxxxxx>
Fixes: 6b658c4863c1 ("scsi: cgroup: Add cgroup_get_from_id()")
Cc: Muneendra <muneendra.kumar@xxxxxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
Acked-by: Mukesh Ojha <quic_mojha@xxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v5.14+
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index e4bb5d57f4d1..5f2090d051ac 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -6049,6 +6049,9 @@ struct cgroup *cgroup_get_from_id(u64 id)
if (!kn)
goto out;
+ if (kernfs_type(kn) != KERNFS_DIR)
+ goto put;
+
rcu_read_lock();
cgrp = rcu_dereference(*(void __rcu __force **)&kn->priv);
@@ -6056,7 +6059,7 @@ struct cgroup *cgroup_get_from_id(u64 id)
cgrp = NULL;
rcu_read_unlock();
-
+put:
kernfs_put(kn);
out:
return cgrp;
