cgroup: avoid copying strings longer than the buffers

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>

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 0b1ffe147f240c39726d79505c4e02e8fe40cd47..18d71fbd39230663babd901b9f7902ba2ec5ab47 100644 (file)
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -1397,7 +1397,7 @@ static char *cgroup_file_name(struct cgroup *cgrp, const struct cftype *cft,
                         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;
 }
 
@@ -1864,9 +1864,9 @@ void init_cgroup_root(struct cgroup_root *root, struct cgroup_sb_opts *opts)
 
        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);
 }