From e7fd37ba12170cc414be8b639dfc2c5f7172fac2 Mon Sep 17 00:00:00 2001
From: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com>
Date: Tue, 12 Dec 2017 09:43:49 +0800
Subject: [PATCH] cgroup: avoid copying strings longer than the buffers
Git-commit: e7fd37ba12170cc414be8b639dfc2c5f7172fac2
Patch-mainline: v4.15-rc8
References: bsc#1051510

cgroup root name and file name have max length limit, we should
avoid copying longer name than that to the name.

Tj: minor update to $SUBJ.

Signed-off-by: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 kernel/cgroup/cgroup.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1221,7 +1221,7 @@ static char *cgroup_file_name(struct cgr
 			 cgroup_on_dfl(cgrp) ? ss->name : ss->legacy_name,
 			 cft->name);
 	else
-		strncpy(buf, cft->name, CGROUP_FILE_NAME_MAX);
+		strscpy(buf, cft->name, CGROUP_FILE_NAME_MAX);
 	return buf;
 }
 
@@ -1638,9 +1638,9 @@ void init_cgroup_root(struct cgroup_root
 
 	root->flags = opts->flags;
 	if (opts->release_agent)
-		strcpy(root->release_agent_path, opts->release_agent);
+		strscpy(root->release_agent_path, opts->release_agent, PATH_MAX);
 	if (opts->name)
-		strcpy(root->name, opts->name);
+		strscpy(root->name, opts->name, MAX_CGROUP_ROOT_NAMELEN);
 	if (opts->cpuset_clone_children)
 		set_bit(CGRP_CPUSET_CLONE_CHILDREN, &root->cgrp.flags);
 }