From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755441Ab1KJFGB (ORCPT ); Thu, 10 Nov 2011 00:06:01 -0500 Received: from cantor2.suse.de ([195.135.220.15]:42466 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934235Ab1KJD2D (ORCPT ); Wed, 9 Nov 2011 22:28:03 -0500 X-Mailbox-Line: From gregkh@clark.kroah.org Wed Nov 9 13:27:15 2011 Message-Id: <20111109212715.605529323@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Wed, 09 Nov 2011 13:27:51 -0800 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Jiri Kosina , Ingo Molnar , Russell King , "H.J. Lu" , , Nicolas Pitre Subject: [149/262] binfmt_elf: fix PIE execution with randomization disabled In-Reply-To: <20111109212847.GA20838@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jiri Kosina commit a3defbe5c337dbc6da911f8cc49ae3cc3b49b453 upstream. The case of address space randomization being disabled in runtime through randomize_va_space sysctl is not treated properly in load_elf_binary(), resulting in SIGKILL coming at exec() time for certain PIE-linked binaries in case the randomization has been disabled at runtime prior to calling exec(). Handle the randomize_va_space == 0 case the same way as if we were not supporting .text randomization at all. Based on original patch by H.J. Lu and Josh Boyer. Signed-off-by: Jiri Kosina Cc: Ingo Molnar Cc: Russell King Cc: H.J. Lu Cc: Tested-by: Josh Boyer Acked-by: Nicolas Pitre Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/binfmt_elf.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -796,7 +796,16 @@ static int load_elf_binary(struct linux_ * might try to exec. This is because the brk will * follow the loader, and is not movable. */ #if defined(CONFIG_X86) || defined(CONFIG_ARM) - load_bias = 0; + /* Memory randomization might have been switched off + * in runtime via sysctl. + * If that is the case, retain the original non-zero + * load_bias value in order to establish proper + * non-randomized mappings. + */ + if (current->flags & PF_RANDOMIZE) + load_bias = 0; + else + load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); #else load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr); #endif