timer/debug: Change /proc/timer_stats from 0644 to 0600

The timer_stats facility should filter and translate PIDs if opened
from a non-initial PID namespace, to avoid leaking information about
the wider system.  It should also not show kernel virtual addresses.
Unfortunately it has now been removed upstream (as redundant)
instead of being fixed.

For stable, fix the leak by restricting access to root only.  A
similar change was already made for the /proc/timer_list file.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/time/timer_stats.c b/kernel/time/timer_stats.c
index 1fb08f21302ece707ac7ea3b5210863cae8b19c2..0334899f1d3e8a31aa580021acc2f75d06feac57 100644 (file)
--- a/kernel/time/timer_stats.c
+++ b/kernel/time/timer_stats.c
@@ -417,7 +417,7 @@ static int __init init_tstats_procfs(void)
 {
        struct proc_dir_entry *pe;
 
-       pe = proc_create("timer_stats", 0644, NULL, &tstats_fops);
+       pe = proc_create("timer_stats", 0600, NULL, &tstats_fops);
        if (!pe)
                return -ENOMEM;
        return 0;