CVE-2013-0914 sa_restorer information leak (rhbz 920499 920510)
This commit is contained in:
Josh Boyer
parent
781a0e5284
commit
18917ef8fb
@ -742,6 +742,9 @@ Patch21268: w1-fix-oops-when-w1_search-is-called-from.patch
|
||||
#rhbz 911771
|
||||
Patch21269: serial-8250-Keep-8250.-xxxx-module-options-functiona.patch
|
||||
|
||||
#CVE-2013-0914 rhbz 920499 920510
|
||||
Patch21270: signal-always-clear-sa_restorer-on-execve.patch
|
||||
|
||||
Patch22000: weird-root-dentry-name-debug.patch
|
||||
|
||||
#selinux ptrace child permissions
|
||||
@ -1442,6 +1445,9 @@ ApplyPatch w1-fix-oops-when-w1_search-is-called-from.patch
|
||||
#rhbz 911771
|
||||
ApplyPatch serial-8250-Keep-8250.-xxxx-module-options-functiona.patch
|
||||
|
||||
#CVE-2013-0914 rhbz 920499 920510
|
||||
ApplyPatch signal-always-clear-sa_restorer-on-execve.patch
|
||||
|
||||
# END OF PATCH APPLICATIONS
|
||||
|
||||
%endif
|
||||
@ -2283,6 +2289,9 @@ fi
|
||||
# ||----w |
|
||||
# || ||
|
||||
%changelog
|
||||
* Tue Mar 12 2013 Josh Boyer <jwboyer@redhat.com>
|
||||
- CVE-2013-0914 sa_restorer information leak (rhbz 920499 920510)
|
||||
|
||||
* Tue Mar 12 2013 Dave Airlie <airlied@redhat.com>
|
||||
- add QXL driver (f19 only)
|
||||
|
||||
|
||||
113
signal-always-clear-sa_restorer-on-execve.patch
Normal file
113
signal-always-clear-sa_restorer-on-execve.patch
Normal file
@ -0,0 +1,113 @@
|
||||
|
||||
Delivered-To: jwboyer@gmail.com
|
||||
Received: by 10.76.169.233 with SMTP id ah9csp99159oac;
|
||||
Mon, 11 Mar 2013 13:14:17 -0700 (PDT)
|
||||
X-Received: by 10.68.179.1 with SMTP id dc1mr24297029pbc.128.1363032856671;
|
||||
Mon, 11 Mar 2013 13:14:16 -0700 (PDT)
|
||||
Return-Path: <linux-kernel-owner@vger.kernel.org>
|
||||
Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67])
|
||||
by mx.google.com with ESMTP id tx10si24737165pbc.272.2013.03.11.13.14.10;
|
||||
Mon, 11 Mar 2013 13:14:16 -0700 (PDT)
|
||||
Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
|
||||
Authentication-Results: mx.google.com;
|
||||
spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mail=linux-kernel-owner@vger.kernel.org
|
||||
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
|
||||
id S1754069Ab3CKUN4 (ORCPT <rfc822;cpulmkl@gmail.com> + 99 others);
|
||||
Mon, 11 Mar 2013 16:13:56 -0400
|
||||
Received: from smtp.outflux.net ([198.145.64.163]:59839 "EHLO smtp.outflux.net"
|
||||
rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP
|
||||
id S1753913Ab3CKUN4 (ORCPT <rfc822;linux-kernel@vger.kernel.org>);
|
||||
Mon, 11 Mar 2013 16:13:56 -0400
|
||||
Received: from www.outflux.net (serenity-end.outflux.net [10.2.0.2])
|
||||
by vinyl.outflux.net (8.14.4/8.14.4/Debian-2ubuntu2) with ESMTP id r2BKDgjn022201;
|
||||
Mon, 11 Mar 2013 13:13:43 -0700
|
||||
Date: Mon, 11 Mar 2013 13:13:42 -0700
|
||||
From: Kees Cook <keescook@chromium.org>
|
||||
To: linux-kernel@vger.kernel.org
|
||||
Cc: Al Viro <viro@zeniv.linux.org.uk>, Oleg Nesterov <oleg@redhat.com>,
|
||||
Andrew Morton <akpm@linux-foundation.org>,
|
||||
"Eric W. Biederman" <ebiederm@xmission.com>,
|
||||
Serge Hallyn <serge.hallyn@canonical.com>,
|
||||
Emese Revfy <re.emese@gmail.com>,
|
||||
PaX Team <pageexec@freemail.hu>, jln@google.com
|
||||
Subject: [PATCH v2] signal: always clear sa_restorer on execve
|
||||
Message-ID: <20130311201342.GA19824@www.outflux.net>
|
||||
MIME-Version: 1.0
|
||||
Content-Type: text/plain; charset=us-ascii
|
||||
Content-Disposition: inline
|
||||
X-MIMEDefang-Filter: outflux$Revision: 1.316 $
|
||||
X-HELO: www.outflux.net
|
||||
X-Scanned-By: MIMEDefang 2.71 on 10.2.0.1
|
||||
Sender: linux-kernel-owner@vger.kernel.org
|
||||
Precedence: bulk
|
||||
List-ID: <linux-kernel.vger.kernel.org>
|
||||
X-Mailing-List: linux-kernel@vger.kernel.org
|
||||
|
||||
When the new signal handlers are set up, the location of sa_restorer
|
||||
is not cleared, leaking a parent process's address space location to
|
||||
children. This allows for a potential bypass of the parent's ASLR by
|
||||
examining the sa_restorer value returned when calling sigaction().
|
||||
|
||||
Based on what should be considered "secret" about addresses, it only
|
||||
matters across the exec not the fork (since the VMAs haven't changed
|
||||
until the exec). But since exec sets SIG_DFL and keeps sa_restorer,
|
||||
this is where it should be fixed.
|
||||
|
||||
Given the few uses of sa_restorer, a "set" function was not written
|
||||
since this would be the only use. Instead, we use __ARCH_HAS_SA_RESTORER,
|
||||
as already done in other places.
|
||||
|
||||
Example of the leak before applying this patch:
|
||||
|
||||
$ cat /proc/$$/maps
|
||||
...
|
||||
7fb9f3083000-7fb9f3238000 r-xp 00000000 fd:01 404469 .../libc-2.15.so
|
||||
...
|
||||
$ ./leak
|
||||
...
|
||||
7f278bc74000-7f278be29000 r-xp 00000000 fd:01 404469 .../libc-2.15.so
|
||||
...
|
||||
1 0 (nil) 0x7fb9f30b94a0
|
||||
2 4000000 (nil) 0x7f278bcaa4a0
|
||||
3 4000000 (nil) 0x7f278bcaa4a0
|
||||
4 0 (nil) 0x7fb9f30b94a0
|
||||
...
|
||||
|
||||
Signed-off-by: Kees Cook <keescook@chromium.org>
|
||||
Reported-by: Emese Revfy <re.emese@gmail.com>
|
||||
Cc: Emese Revfy <re.emese@gmail.com>
|
||||
Cc: PaX Team <pageexec@freemail.hu>
|
||||
Cc: stable@vger.kernel.org
|
||||
---
|
||||
v2:
|
||||
- clarify commit, explain use of #ifdef.
|
||||
---
|
||||
kernel/signal.c | 3 +++
|
||||
1 file changed, 3 insertions(+)
|
||||
|
||||
diff --git a/kernel/signal.c b/kernel/signal.c
|
||||
index 2ec870a..8c8e3ca 100644
|
||||
--- a/kernel/signal.c
|
||||
+++ b/kernel/signal.c
|
||||
@@ -485,6 +485,9 @@ flush_signal_handlers(struct task_struct *t, int force_default)
|
||||
if (force_default || ka->sa.sa_handler != SIG_IGN)
|
||||
ka->sa.sa_handler = SIG_DFL;
|
||||
ka->sa.sa_flags = 0;
|
||||
+#ifdef __ARCH_HAS_SA_RESTORER
|
||||
+ ka->sa.sa_restorer = NULL;
|
||||
+#endif
|
||||
sigemptyset(&ka->sa.sa_mask);
|
||||
ka++;
|
||||
}
|
||||
--
|
||||
1.7.9.5
|
||||
|
||||
|
||||
--
|
||||
Kees Cook
|
||||
Chrome OS Security
|
||||
--
|
||||
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
|
||||
the body of a message to majordomo@vger.kernel.org
|
||||
More majordomo info at http://vger.kernel.org/majordomo-info.html
|
||||
Please read the FAQ at http://www.tux.org/lkml/
|
||||
Loading…
Reference in New Issue
Block a user