From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9F0B8C43441 for ; Sun, 11 Nov 2018 20:34:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5CC2C20818 for ; Sun, 11 Nov 2018 20:34:18 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5CC2C20818 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730256AbeKLFsP (ORCPT ); Mon, 12 Nov 2018 00:48:15 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:49890 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730182AbeKLFsN (ORCPT ); Mon, 12 Nov 2018 00:48:13 -0500 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gLvsZ-0000oF-24; Sun, 11 Nov 2018 19:58:43 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gLvsW-0001jD-HO; Sun, 11 Nov 2018 19:58:40 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Michal Hocko" , "Oscar Salvador" , "Nicolas Pitre" , "Linus Torvalds" , syzbot+5dcb560fe12aa5091c06@syzkaller.appspotmail.com, "Kees Cook" , "Tetsuo Handa" Date: Sun, 11 Nov 2018 19:49:05 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 253/366] fs, elf: make sure to page align bss in load_elf_library In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.61-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Oscar Salvador commit 24962af7e1041b7e50c1bc71d8d10dc678c556b5 upstream. The current code does not make sure to page align bss before calling vm_brk(), and this can lead to a VM_BUG_ON() in __mm_populate() due to the requested lenght not being correctly aligned. Let us make sure to align it properly. Kees: only applicable to CONFIG_USELIB kernels: 32-bit and configured for libc5. Link: http://lkml.kernel.org/r/20180705145539.9627-1-osalvador@techadventures.net Signed-off-by: Oscar Salvador Reported-by: syzbot+5dcb560fe12aa5091c06@syzkaller.appspotmail.com Tested-by: Tetsuo Handa Acked-by: Kees Cook Cc: Michal Hocko Cc: Nicolas Pitre Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Ben Hutchings --- fs/binfmt_elf.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1083,9 +1083,8 @@ static int load_elf_library(struct file goto out_free_ph; } - len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + - ELF_MIN_ALIGN - 1); - bss = eppnt->p_memsz + eppnt->p_vaddr; + len = ELF_PAGEALIGN(eppnt->p_filesz + eppnt->p_vaddr); + bss = ELF_PAGEALIGN(eppnt->p_memsz + eppnt->p_vaddr); if (bss > len) { error = vm_brk(len, bss - len); if (BAD_ADDR(error))