public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Marcus Meissner <meissner@suse.de>
To: tglx@linutronix.de, mingo@elte.hu, a.p.zijlstra@chello.nl,
	akpm@linux-foundation.org, rusty@rustcorp.com.au,
	torvalds@linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH] kernel/time: Make /proc/timer_list mode 0400
Date: Wed, 17 Nov 2010 18:08:22 +0100	[thread overview]
Message-ID: <20101117170822.GW20727@suse.de> (raw)

Hi,

/proc/timer_list contains kernel addresses, like e.g.:
 #0: <c000000001404158>, tick_sched_timer, S:01, .tick_nohz_restart_sched_tick, swapper/0
 ...

Avoid leaking them to user space to make writing kernel exploits a bit harder.

(I currently cannot think of a userland tool that uses this, this is
likely pretty much root-only.)

Ciao, Marcus

Signed-off-by: Marcus Meissner <meissner@suse.de>
---
 kernel/time/timer_list.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/time/timer_list.c b/kernel/time/timer_list.c
index ab8f5e3..5ae1ce3 100644
--- a/kernel/time/timer_list.c
+++ b/kernel/time/timer_list.c
@@ -293,7 +293,7 @@ static int __init init_timer_list_procfs(void)
 {
 	struct proc_dir_entry *pe;
 
-	pe = proc_create("timer_list", 0444, NULL, &timer_list_fops);
+	pe = proc_create("timer_list", 0400, NULL, &timer_list_fops);
 	if (!pe)
 		return -ENOMEM;
 	return 0;
-- 
1.7.1


             reply	other threads:[~2010-11-17 17:08 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-17 17:08 Marcus Meissner [this message]
2010-11-17 17:18 ` [PATCH] kernel/time: Make /proc/timer_list mode 0400 Peter Zijlstra
2010-11-17 17:21   ` Marcus Meissner
2010-11-17 17:33     ` Peter Zijlstra
2010-11-30 19:21     ` Pavel Machek
2010-11-17 20:30   ` Andrew Morton
2010-11-17 20:37     ` Thomas Gleixner
2010-11-18  8:12       ` Ingo Molnar
2010-11-18  8:28         ` Eric Dumazet
2010-11-30 19:22         ` Pavel Machek

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20101117170822.GW20727@suse.de \
    --to=meissner@suse.de \
    --cc=a.p.zijlstra@chello.nl \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=rusty@rustcorp.com.au \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox