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=-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 462DAC43331 for ; Thu, 2 Apr 2020 04:11:01 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0868E20784 for ; Thu, 2 Apr 2020 04:11:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="d3e9Kfdj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0868E20784 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id AA73A8E0089; Thu, 2 Apr 2020 00:11:00 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A55948E000D; Thu, 2 Apr 2020 00:11:00 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9931D8E0089; Thu, 2 Apr 2020 00:11:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0221.hostedemail.com [216.40.44.221]) by kanga.kvack.org (Postfix) with ESMTP id 7D1CC8E000D for ; Thu, 2 Apr 2020 00:11:00 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 4C8E14995E0 for ; Thu, 2 Apr 2020 04:11:00 +0000 (UTC) X-FDA: 76661589480.26.coat41_600d09f334738 X-HE-Tag: coat41_600d09f334738 X-Filterd-Recvd-Size: 3146 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Thu, 2 Apr 2020 04:10:59 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (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 041C72074D; Thu, 2 Apr 2020 04:10:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585800659; bh=uuZCUsjKaln/ZQr38pGS+xBL/xNcMqqIgbCMKYhJQjM=; h=Date:From:To:Subject:In-Reply-To:From; b=d3e9Kfdj882LEKDD/hiIJp/hUbjQvmKybrFdiLSjG6P+9hbMSi1n0Qs1z7vVJ5cbP pSC8BaagaUj3nn4Sms0+9jC97cAJR7YtXAQusTyHqAa7KHluj7cP6Atna4OwzYtytv WM7JceeikbkPxxNgXg/6WwxOQvMYC69iX0Cm3xuA= Date: Wed, 01 Apr 2020 21:10:58 -0700 From: Andrew Morton To: 3ntr0py1337@gmail.com, akpm@linux-foundation.org, lee.schermerhorn@hp.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, rdunlap@infradead.org, torvalds@linux-foundation.org Subject: [patch 137/155] mm: mempolicy: require at least one nodeid for MPOL_PREFERRED Message-ID: <20200402041058.1vVjHmGV2%akpm@linux-foundation.org> In-Reply-To: <20200401210155.09e3b9742e1c6e732f5a7250@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Randy Dunlap Subject: mm: mempolicy: require at least one nodeid for MPOL_PREFERRED Using an empty (malformed) nodelist that is not caught during mount option parsing leads to a stack-out-of-bounds access. The option string that was used was: "mpol=prefer:,". However, MPOL_PREFERRED requires a single node number, which is not being provided here. Add a check that 'nodes' is not empty after parsing for MPOL_PREFERRED's nodeid. Link: http://lkml.kernel.org/r/89526377-7eb6-b662-e1d8-4430928abde9@infradead.org Fixes: 095f1fc4ebf3 ("mempolicy: rework shmem mpol parsing and display") Reported-by: Entropy Moe <3ntr0py1337@gmail.com> Reported-by: syzbot+b055b1a6b2b958707a21@syzkaller.appspotmail.com Tested-by: syzbot+b055b1a6b2b958707a21@syzkaller.appspotmail.com Signed-off-by: Randy Dunlap Cc: Lee Schermerhorn Signed-off-by: Andrew Morton --- mm/mempolicy.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/mm/mempolicy.c~mm-mempolicy-require-at-least-one-nodeid-for-mpol_preferred +++ a/mm/mempolicy.c @@ -2898,7 +2898,9 @@ int mpol_parse_str(char *str, struct mem switch (mode) { case MPOL_PREFERRED: /* - * Insist on a nodelist of one node only + * Insist on a nodelist of one node only, although later + * we use first_node(nodes) to grab a single node, so here + * nodelist (or nodes) cannot be empty. */ if (nodelist) { char *rest = nodelist; @@ -2906,6 +2908,8 @@ int mpol_parse_str(char *str, struct mem rest++; if (*rest) goto out; + if (nodes_empty(nodes)) + goto out; } break; case MPOL_INTERLEAVE: _