From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755727Ab0KZRYP (ORCPT ); Fri, 26 Nov 2010 12:24:15 -0500 Received: from smtp6-g21.free.fr ([212.27.42.6]:38174 "EHLO smtp6-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754740Ab0KZRYJ (ORCPT ); Fri, 26 Nov 2010 12:24:09 -0500 Date: Fri, 26 Nov 2010 18:23:55 +0100 From: mat To: Valdis.Kletnieks@vt.edu Cc: linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, linux-next@vger.kernel.org, Arjan van de Ven , James Morris , Andrew Morton , Andi Kleen , Thomas Gleixner , "H. Peter Anvin" , Ingo Molnar , Rusty Russell , Stephen Rothwell , Dave Jones , Siarhei Liakh , Kees Cook Subject: Re: [PATCH 3/3 V13] RO/NX protection for loadable kernel Message-ID: <20101126182355.62615dff@mat-laptop> In-Reply-To: <24422.1290656467@localhost> References: <4CE2F914.9070106@free.fr> <24422.1290656467@localhost> X-Mailer: Claws Mail 3.7.6 (GTK+ 2.22.0; i486-pc-linux-gnu) Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="MP_/u4AfbfrTKD9Qh3gR_9SQMcY" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --MP_/u4AfbfrTKD9Qh3gR_9SQMcY Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Le Wed, 24 Nov 2010 22:41:07 -0500, Valdis.Kletnieks@vt.edu a =E9crit : > On Tue, 16 Nov 2010 22:35:16 +0100, matthieu castet said: >=20 > > This patch is a logical extension of the protection provided by > > CONFIG_DEBUG_RODATA to LKMs. The protection is provided by splitting > > module_core and module_init into three logical parts each and > > setting appropriate page access permissions for each individual > > section: > >=20 > > 1. Code: RO+X > > 2. RO data: RO+NX > > 3. RW data: RW+NX >=20 > This is incompatible with CONFIG_JUMP_LABEL: >=20 > [ 252.093624] BUG: unable to handle kernel paging request at > ffffffffa0680764 [ 252.094008] IP: [] > generic_swap+0xa/0x1a [ 252.094008] PGD 1a1e067 PUD 1a22063 PMD > 1093ac067 PTE 8000000109786161 [ 252.094008] Oops: 0003 [#1] PREEMPT > SMP=20 >=20 > [ 252.094008] Pid: 3740, comm: modprobe Not tainted > 2.6.37-rc3-mmotm1123 #1 0X564R/Latitude E6500 [ 252.094008] RIP: > 0010:[] [] generic_swap+0xa/0x1a > [ 252.094008] RSP: 0018:ffff88011a217d98 EFLAGS: 00010206 > [ 252.094008] RAX: 00000000000000d9 RBX: 0000000000000030 RCX: > 000000000000007c [ 252.094008] RDX: 0000000000000017 RSI: > ffffffffa0680794 RDI: ffffffffa0680764 [ 252.094008] RBP: > ffff88011a217d98 R08: 0000000000000000 R09: ffff88011a217d38 > [ 252.094008] R10: 0000000000000000 R11: 000000000000013d R12: > ffffffffa0680764 [ 252.094008] R13: 0000000000000018 R14: > 0000000000000018 R15: 0000000000000018 [ 252.094008] FS: > 00007f6ecb897720(0000) GS:ffff8800df100000(0000) > knlGS:0000000000000000 [ 252.094008] CS: 0010 DS: 0000 ES: 0000 > CR0: 000000008005003b [ 252.094008] CR2: ffffffffa0680764 CR3: > 000000011911e000 CR4: 00000000000406e0 [ 252.094008] DR0: > 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > [ 252.094008] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: > 0000000000000400 [ 252.094008] Process modprobe (pid: 3740, > threadinfo ffff88011a216000, task ffff88011861e300) [ 252.094008] > Stack: [ 252.094008] ffff88011a217e28 ffffffff81226007 > ffffffff81a31158 0000000000000000 [ 252.094008] 0000000000000030 > 0000000000000048 ffffffff8105fa34 ffffffff81225ed6 [ 252.094008] > ffffffff00000018 ffffffff00000018 0000000000000018 00000030ffffffff > [ 252.094008] Call Trace: [ 252.094008] [] > sort+0x117/0x1b0 [ 252.094008] [] ? > jump_label_cmp+0x0/0x1b [ 252.094008] [] ? > generic_swap+0x0/0x1a [ 252.094008] [] > sort_jump_label_entries+0x2b/0x2d [ 252.094008] > [] jump_label_module_notify+0x58/0x253 > [ 252.094008] [] notifier_call_chain+0x54/0x81 > [ 252.094008] [] > __blocking_notifier_call_chain+0x5c/0x79 [ 252.094008] > [] blocking_notifier_call_chain+0xf/0x11 > [ 252.094008] [] sys_init_module+0x76/0x1f5 > [ 252.094008] [] system_call_fastpath+0x16/0x1b > [ 252.094008] Code: 05 ff c0 48 29 f7 48 39 f7 73 f6 48 89 3a c9 c3 > 90 90 90 8b 07 8b 16 55 89 17 48 89 e5 89 06 c9 c3 55 48 89 e5 8a 07 > 8a 0e ff ca <88> 0f 48 ff c7 88 06 48 ff c6 85 d2 7f ec c9 c3 55 89 > d0 48 89 [ 252.094008] RIP [] > generic_swap+0xa/0x1a [ 252.094008] RSP > [ 252.094008] CR2: ffffffffa0680764 [ 252.094008] ---[ end trace > f88479be6b01e4c4 ]--- >=20 >=20 > > +config DEBUG_SET_MODULE_RONX > > + bool "Set loadable kernel module data as NX and text as RO" > > + default n > > + depends on X86 && MODULES >=20 > depends on X86 && MODULES && !JUMP_LABEL could you try the attached patch ? on module load, we sort the __jump_table section. So we should make it writable. Matthieu --MP_/u4AfbfrTKD9Qh3gR_9SQMcY Content-Type: text/x-patch Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=jmp_label.diff diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h index f52d42e..574dbc2 100644 --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -14,7 +14,7 @@ do { \ asm goto("1:" \ JUMP_LABEL_INITIAL_NOP \ - ".pushsection __jump_table, \"a\" \n\t"\ + ".pushsection __jump_table, \"aw\" \n\t"\ _ASM_PTR "1b, %l[" #label "], %c0 \n\t" \ ".popsection \n\t" \ : : "i" (key) : : label); \ --MP_/u4AfbfrTKD9Qh3gR_9SQMcY--