[PATCH 4.9 03/93] cgroup: fix error return value from cgroup_subtree_control()

From: Greg Kroah-Hartman
Date: Wed Aug 09 2017 - 14:14:38 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Tejun Heo <tj@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
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;