This is a note to let you know that I've just added the patch titled
cgroup: cgroup_get_from_id() must check the looked-up kn is a directory
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cgroup-cgroup_get_from_id-must-check-the-looked-up-k.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3da6a620885c933439c7c8ec5cc789f9e4018058
Author: Ming Lei <ming.lei@xxxxxxxxxx>
Date: Fri Sep 23 19:51:19 2022 +0800
cgroup: cgroup_get_from_id() must check the looked-up kn is a directory
[ Upstream commit df02452f3df069a59bc9e69c84435bf115cb6e37 ]
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>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 97282d6b5d18..4b19f7fc4deb 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -6025,6 +6025,9 @@ 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);
@@ -6032,7 +6035,7 @@ struct cgroup *cgroup_get_from_id(u64 id)
cgrp = NULL;
rcu_read_unlock();
-
+put:
kernfs_put(kn);
out:
return cgrp;
