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@vger.kernel.org.
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@redhat.com 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@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
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;