From: Ming Lei ming.lei@redhat.com
commit df02452f3df069a59bc9e69c84435bf115cb6e37 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/cgroup/cgroup.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -6026,6 +6026,9 @@ 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); @@ -6033,7 +6036,7 @@ struct cgroup *cgroup_get_from_id(u64 id cgrp = NULL;
rcu_read_unlock(); - +put: kernfs_put(kn); out: return cgrp;