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 087204c733ebb39c881c2b58b6937ad4ffe3d756..c74920f318c56b10462ac0422ad1ff3606e0fbee 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;