From nobody Wed Sep 17 19:24:05 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4756C4332F for ; Thu, 15 Dec 2022 19:46:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230223AbiLOTqt (ORCPT ); Thu, 15 Dec 2022 14:46:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45000 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229784AbiLOTqe (ORCPT ); Thu, 15 Dec 2022 14:46:34 -0500 Received: from smtpout.efficios.com (smtpout.efficios.com [167.114.26.122]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F2D252149; Thu, 15 Dec 2022 11:46:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1671133590; bh=vhXovAdMFvjGdI7fvSIRELXEjd78VENxVI/4IdKMMb8=; h=From:To:Cc:Subject:Date:From; b=ncnIb0WfhtEKF/kGA0uSnMmTXuI1l6JC9LQo0I6g4fETpGHCgxttX9WGWkYyDKqNd 9zcrYKXVjeuoDVDqA85XRhQxqgcVvDyAjDxyksOIqLj/L8vLnw2Nc3WXgHJ0lJwHNY 2lvDXcL7e0cY/5AVqL5qaJeMgecKnv1PxfWJ9GbQmi/UxORTXN5RCLaVTubrnzvhod 7rsyLENiWhIkh2pVtl2jN1FfUCDYW/xWglJjORi7zYr6C63AbyXAbqDWp2JmJaMh1H hoLjjwfTdeAtfpYLchBMfEFNFHv3wG7hX/sfEjeynMOzEMyeH+yn9jRp9K6hy+vGCk 8jJ3W40iqr5Rw== Received: from localhost.localdomain (192-222-180-24.qc.cable.ebox.net [192.222.180.24]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4NY2mQ0KT9zbb6; Thu, 15 Dec 2022 14:46:30 -0500 (EST) From: Mathieu Desnoyers To: Michal Hocko Cc: linux-kernel@vger.kernel.org, Mathieu Desnoyers , Randy Dunlap , "Huang, Ying" , "Aneesh Kumar K . V" , Dave Hansen , Feng Tang , Michal Hocko , Andrea Arcangeli , Mel Gorman , Mike Kravetz , Vlastimil Babka , Andi Kleen , Dan Williams , linux-api@vger.kernel.org, Andrew Morton , stable@vger.kernel.org Subject: [PATCH] mm/mempolicy: Fix memory leak in set_mempolicy_home_node system call Date: Thu, 15 Dec 2022 14:46:21 -0500 Message-Id: <20221215194621.202816-1-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" When encountering any vma in the range with policy other than MPOL_BIND or MPOL_PREFERRED_MANY, an error is returned without issuing a mpol_put on the policy just allocated with mpol_dup(). This allows arbitrary users to leak kernel memory. Fixes: c6018b4b2549 ("mm/mempolicy: add set_mempolicy_home_node syscall") Signed-off-by: Mathieu Desnoyers Reviewed-by: Randy Dunlap Reviewed-by: "Huang, Ying" Reviewed-by: Aneesh Kumar K.V Acked-by: Michal Hocko Cc: Aneesh Kumar K.V Cc: Dave Hansen Cc: Feng Tang Cc: Michal Hocko Cc: Andrea Arcangeli Cc: Mel Gorman Cc: Mike Kravetz Cc: Randy Dunlap Cc: Vlastimil Babka Cc: Andi Kleen Cc: Dan Williams Cc: Huang Ying Cc: Cc: Andrew Morton Cc: stable@vger.kernel.org # 5.17+ --- mm/mempolicy.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 61aa9aedb728..02c8a712282f 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1540,6 +1540,7 @@ SYSCALL_DEFINE4(set_mempolicy_home_node, unsigned lon= g, start, unsigned long, le * the home node for vmas we already updated before. */ if (new->mode !=3D MPOL_BIND && new->mode !=3D MPOL_PREFERRED_MANY) { + mpol_put(new); err =3D -EOPNOTSUPP; break; } --=20 2.25.1