cgroups: censor kernel pointer in debug files

As found in grsecurity, this avoids exposing a kernel pointer through
the cgroup debug entries.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 56eba9caa632adcc118114d8aa55cbab00895495..1dc22f6b49f5e06c4af22222dfb1b32c885ce16a 100644 (file)
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -1329,7 +1329,7 @@ static int cgroup_css_links_read(struct seq_file *seq, void *v)
                struct task_struct *task;
                int count = 0;
 
-               seq_printf(seq, "css_set %p\n", cset);
+               seq_printf(seq, "css_set %pK\n", cset);
 
                list_for_each_entry(task, &cset->tasks, cg_list) {
                        if (count++ > MAX_TASKS_SHOWN_PER_CSS)