Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753742AbaFLVB0 (ORCPT ); Thu, 12 Jun 2014 17:01:26 -0400 Received: from smtp.outflux.net ([198.145.64.163]:56874 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753623AbaFLVBX (ORCPT ); Thu, 12 Jun 2014 17:01:23 -0400 From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , "Rafael J. Wysocki" , "H. Peter Anvin" , Randy Dunlap , Thomas Gleixner , Ingo Molnar , x86@kernel.org, Len Brown , Pavel Machek , Wei Yongjun , linux-doc@vger.kernel.org, linux-pm@vger.kernel.org Subject: [PATCH v2 2/2] x86, kaslr: boot-time selectable with hibernation Date: Thu, 12 Jun 2014 14:00:33 -0700 Message-Id: <1402606833-9825-3-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1402606833-9825-1-git-send-email-keescook@chromium.org> References: <1402606833-9825-1-git-send-email-keescook@chromium.org> X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Changes kASLR from being compile-time selectable (blocked by CONFIG_HIBERNATION), to being boot-time selectable (with hibernation available by default) via the "kaslr" kernel command line. Signed-off-by: Kees Cook --- Documentation/kernel-parameters.txt | 11 +++++++---- arch/x86/Kconfig | 1 - arch/x86/boot/compressed/aslr.c | 9 ++++++++- kernel/power/hibernate.c | 6 ++++++ 4 files changed, 21 insertions(+), 6 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index f8f0466b8b1d..884904975d0b 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1474,6 +1474,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. js= [HW,JOY] Analog joystick See Documentation/input/joystick.txt. + kaslr/nokaslr [X86] + Enable/disable kernel and module base offset ASLR + (Address Space Layout Randomization) if built into + the kernel. When CONFIG_HIBERNATION is selected, + kASLR is disabled by default. When kASLR is enabled, + hibernation will be disabled. + keepinitrd [HW,ARM] kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter @@ -2110,10 +2117,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted. noapic [SMP,APIC] Tells the kernel to not make use of any IOAPICs that may be present in the system. - nokaslr [X86] - Disable kernel and module base offset ASLR (Address - Space Layout Randomization) if built into the kernel. - noautogroup Disable scheduler automatic task group creation. nobats [PPC] Do not use BATs for mapping kernel lowmem diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index b660088c220d..7fdb639f1b63 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1671,7 +1671,6 @@ config RELOCATABLE config RANDOMIZE_BASE bool "Randomize the address of the kernel image" depends on RELOCATABLE - depends on !HIBERNATION default n ---help--- Randomizes the physical and virtual address at which the diff --git a/arch/x86/boot/compressed/aslr.c b/arch/x86/boot/compressed/aslr.c index 4dbf967da50d..fc6091abedb7 100644 --- a/arch/x86/boot/compressed/aslr.c +++ b/arch/x86/boot/compressed/aslr.c @@ -289,10 +289,17 @@ unsigned char *choose_kernel_location(unsigned char *input, unsigned long choice = (unsigned long)output; unsigned long random; +#ifdef CONFIG_HIBERNATION + if (!cmdline_find_option_bool("kaslr")) { + debug_putstr("KASLR disabled by default...\n"); + goto out; + } +#else if (cmdline_find_option_bool("nokaslr")) { - debug_putstr("KASLR disabled...\n"); + debug_putstr("KASLR disabled by cmdline...\n"); goto out; } +#endif /* Record the various known unsafe memory ranges. */ mem_avoid_init((unsigned long)input, input_size, diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index fd3e785dbc37..c1e0daa032b3 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -1150,6 +1150,11 @@ static int __init nohibernate_setup(char *str) return 1; } +static int __init kaslr_nohibernate_setup(char *str) +{ + return nohibernate_setup(str); +} + __setup("noresume", noresume_setup); __setup("resume_offset=", resume_offset_setup); __setup("resume=", resume_setup); @@ -1157,3 +1162,4 @@ __setup("hibernate=", hibernate_setup); __setup("resumewait", resumewait_setup); __setup("resumedelay=", resumedelay_setup); __setup("nohibernate", nohibernate_setup); +__setup("kaslr", kaslr_nohibernate_setup); -- 1.7.9.5 -- 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/