From patchwork Fri Jan 17 03:05:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 233665 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=-3.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS autolearn=no 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 81541C33CAF for ; Fri, 17 Jan 2020 03:05:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 50347207E0 for ; Fri, 17 Jan 2020 03:05:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579230346; bh=YLHeXOAI167QYsQ85lU10nNKpLrqY7T51zHlepFSn7Q=; h=Date:From:To:Subject:List-ID:From; b=aUBNUm4KYqNGLm5k8JY7JzxoOpo2oVvYAVH2M0auIlerM63tN9rCS8guD/VvcPTAf KOsp2MDEOXUHA5AP2pfzSnljElONyoFRnLGr6j4b8lLsZvd3+miG7HmIqyStFTZKDS 3LjJFFGeXIFAP9n+B3KID5SDw77kTVfjC896U9Ak= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389217AbgAQDFp (ORCPT ); Thu, 16 Jan 2020 22:05:45 -0500 Received: from mail.kernel.org ([198.145.29.99]:42808 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388298AbgAQDFp (ORCPT ); Thu, 16 Jan 2020 22:05:45 -0500 Received: from X1 (nat-ab2241.sltdut.senawave.net [162.218.216.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 99A09206D7; Fri, 17 Jan 2020 03:05:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579230344; bh=YLHeXOAI167QYsQ85lU10nNKpLrqY7T51zHlepFSn7Q=; h=Date:From:To:Subject:From; b=yqlVpaX3pa2IpgMsq+scoUQ6AIBnDg5LQhYqJrbkc1nT9yjyiBURc0fw8kn7FJnwH EjYPNxvVLNkE50fsRuRGOA0SBdtQJ2203XZvW4vv3/M+LO54aejpNegruGaCCc9Czh fCSQACASU7qDyrj0+PDbhfEXBkSO+BRkcBvdoNRw= Date: Thu, 16 Jan 2020 19:05:44 -0800 From: akpm@linux-foundation.org To: mm-commits@vger.kernel.org, vbabka@suse.cz, stable@vger.kernel.org, mhocko@kernel.org, lee.schermerhorn@hp.com, hughd@google.com, aarcange@redhat.com, dan.carpenter@oracle.com Subject: + mm-mempolicyc-fix-out-of-bounds-write-in-mpol_parse_str.patch added to -mm tree Message-ID: <20200117030544.atCbT%akpm@linux-foundation.org> User-Agent: s-nail v14.9.10 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch titled Subject: mm/mempolicy.c: fix out of bounds write in mpol_parse_str() has been added to the -mm tree. Its filename is mm-mempolicyc-fix-out-of-bounds-write-in-mpol_parse_str.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-mempolicyc-fix-out-of-bounds-write-in-mpol_parse_str.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-mempolicyc-fix-out-of-bounds-write-in-mpol_parse_str.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Dan Carpenter Subject: mm/mempolicy.c: fix out of bounds write in mpol_parse_str() What we are trying to do is change the '=' character to a NUL terminator and then at the end of the function we restore it back to an '='. The problem is there are two error paths where we jump to the end of the function before we have replaced the '=' with NUL. We end up putting the '=' in the wrong place (possibly one element before the start of the buffer). Link: http://lkml.kernel.org/r/20200115055426.vdjwvry44nfug7yy@kili.mountain Reported-by: syzbot+e64a13c5369a194d67df@syzkaller.appspotmail.com Fixes: 095f1fc4ebf3 ("mempolicy: rework shmem mpol parsing and display") Signed-off-by: Dan Carpenter Acked-by: Vlastimil Babka Dmitry Vyukov Cc: Michal Hocko Cc: Dan Carpenter Cc: Lee Schermerhorn Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: Signed-off-by: Andrew Morton --- mm/mempolicy.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/mm/mempolicy.c~mm-mempolicyc-fix-out-of-bounds-write-in-mpol_parse_str +++ a/mm/mempolicy.c @@ -2821,6 +2821,9 @@ int mpol_parse_str(char *str, struct mem char *flags = strchr(str, '='); int err = 1, mode; + if (flags) + *flags++ = '\0'; /* terminate mode string */ + if (nodelist) { /* NUL-terminate mode or flags string */ *nodelist++ = '\0'; @@ -2831,9 +2834,6 @@ int mpol_parse_str(char *str, struct mem } else nodes_clear(nodes); - if (flags) - *flags++ = '\0'; /* terminate mode string */ - mode = match_string(policy_modes, MPOL_MAX, str); if (mode < 0) goto out;