Patch "cgroup: fix error return value from cgroup_subtree_control()" has been added to the 4.9-stable tree

Patch "cgroup: fix error return value from cgroup_subtree_control()" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    cgroup: fix error return value from cgroup_subtree_control()

to the 4.9-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-fix-error-return-value-from-cgroup_subtree_control.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 3c74541777302eec43a0d1327c4d58b8659a776b Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Sun, 23 Jul 2017 08:14:15 -0400
Subject: cgroup: fix error return value from cgroup_subtree_control()

From: Tejun Heo <tj@kernel.org>

commit 3c74541777302eec43a0d1327c4d58b8659a776b upstream.

While refactoring, f7b2814bb9b6 ("cgroup: factor out
cgroup_{apply|finalize}_control() from
cgroup_subtree_control_write()") broke error return value from the
function.  The return value from the last operation is always
overridden to zero.  Fix it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 kernel/cgroup.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -3487,11 +3487,11 @@ static ssize_t cgroup_subtree_control_wr
 	cgrp->subtree_control &= ~disable;
 
 	ret = cgroup_apply_control(cgrp);
-
 	cgroup_finalize_control(cgrp, ret);
+	if (ret)
+		goto out_unlock;
 
 	kernfs_activate(cgrp->kn);
-	ret = 0;
 out_unlock:
 	cgroup_kn_unlock(of->kn);
 	return ret ?: nbytes;


Patches currently in stable-queue which might be from tj@kernel.org are

queue-4.9/cgroup-create-dfl_root-files-on-subsys-registration.patch
queue-4.9/cgroup-fix-error-return-value-from-cgroup_subtree_control.patch
queue-4.9/workqueue-restore-wq_unbound-max_active-1-to-be-ordered.patch
queue-4.9/libata-array-underflow-in-ata_find_dev.patch