Commit df02452f authored by Ming Lei's avatar Ming Lei Committed by Tejun Heo
Browse files

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: default avatarMarco Patalano <mpatalan@redhat.com>
Fixes: 6b658c48 ("scsi: cgroup: Add cgroup_get_from_id()")
Cc: Muneendra <muneendra.kumar@broadcom.com>
Signed-off-by: default avatarMing Lei <ming.lei@redhat.com>
Acked-by: default avatarMukesh Ojha <quic_mojha@quicinc.com>
Cc: stable@vger.kernel.org # v5.14+
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent a81e18e9

kernel/cgroup/cgroup.c

+4 −1
Original line number Diff line number Diff line
@@ -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;