From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933025Ab0G3SHd (ORCPT ); Fri, 30 Jul 2010 14:07:33 -0400 Received: from kroah.org ([198.145.64.141]:59241 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932807Ab0G3R5r (ORCPT ); Fri, 30 Jul 2010 13:57:47 -0400 X-Mailbox-Line: From gregkh@clark.site Fri Jul 30 10:51:50 2010 Message-Id: <20100730175150.890894512@clark.site> User-Agent: quilt/0.48-11.2 Date: Fri, 30 Jul 2010 10:53:24 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, =?ISO-8859-15?q?Krzysztof=20Ha=C5=82asa?= , Michal Marek Subject: [187/205] kbuild: Fix modpost segfault In-Reply-To: <20100730175238.GA3924@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 2.6.34-stable review patch. If anyone has any objections, please let us know. ------------------ From: Krzysztof Halasa commit 1c938663d58b5b2965976a6f54cc51b5d6f691aa upstream. Alan writes: > program: /home/alan/GitTrees/linux-2.6-mid-ref/scripts/mod/modpost -o > Module.symvers -S vmlinux.o > > Program received signal SIGSEGV, Segmentation fault. It just hit me. It's the offset calculation in reloc_location() which overflows: return (void *)elf->hdr + sechdrs[section].sh_offset + (r->r_offset - sechdrs[section].sh_addr); E.g. for the first rodata r entry: r->r_offset < sechdrs[section].sh_addr and the expression in the parenthesis produces 0xFFFFFFE0 or something equally wise. Reported-by: Alan Signed-off-by: Krzysztof Hałasa Tested-by: Alan Signed-off-by: Michal Marek Signed-off-by: Greg Kroah-Hartman --- scripts/mod/modpost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -1318,7 +1318,7 @@ static unsigned int *reloc_location(stru int section = sechdr->sh_info; return (void *)elf->hdr + sechdrs[section].sh_offset + - (r->r_offset - sechdrs[section].sh_addr); + r->r_offset - sechdrs[section].sh_addr; } static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)