From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751255AbeCIFWO (ORCPT ); Fri, 9 Mar 2018 00:22:14 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:6208 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751065AbeCIFWN (ORCPT ); Fri, 9 Mar 2018 00:22:13 -0500 From: Yisheng Xie Subject: [PATCH] mm/mempolicy: Avoid use uninitialized preferred_node To: Alexander Potapenko , References: CC: Linux Memory Management List , Dmitriy Vyukov , , "mhocko@suse.com" , Linux Kernel Mailing List Message-ID: <4ebee1c2-57f6-bcb8-0e2d-1833d1ee0bb7@huawei.com> Date: Fri, 9 Mar 2018 13:21:08 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.177.29.40] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Alexander reported an use of uninitialized memory in __mpol_equal(), which is caused by incorrect use of preferred_node. When mempolicy in mode MPOL_PREFERRED with flags MPOL_F_LOCAL, it use numa_node_id() instead of preferred_node, however, __mpol_equeue() use preferred_node without check whether it is MPOL_F_LOCAL or not. Reported-by: Alexander Potapenko Signed-off-by: Yisheng Xie --- mm/mempolicy.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index d879f1d..641545e 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2124,6 +2124,9 @@ bool __mpol_equal(struct mempolicy *a, struct mempolicy *b) case MPOL_INTERLEAVE: return !!nodes_equal(a->v.nodes, b->v.nodes); case MPOL_PREFERRED: + /* a's flags is the same as b's */ + if (a->flags & MPOL_F_LOCAL) + return true; return a->v.preferred_node == b->v.preferred_node; default: BUG(); -- 1.8.3.1