From nobody Wed Dec 31 08:28:51 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 A499FC4167D for ; Mon, 6 Nov 2023 23:34:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233471AbjKFXeU (ORCPT ); Mon, 6 Nov 2023 18:34:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233321AbjKFXeQ (ORCPT ); Mon, 6 Nov 2023 18:34:16 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 17C6983; Mon, 6 Nov 2023 15:34:14 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 55F12C433CA; Mon, 6 Nov 2023 23:34:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699313653; bh=19smz8vjkknnlftKxQDFJP/XhxeknF20W/DyGkIS8Os=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D1wTspPUeGLo6x8Q/O1NGf9r8R7Y77Rea13Em+t/uPG+M8MB1RkYbqzvbkzEFu/2o +EbJZr5EpmuJNr37DT7pK4w7FQz0S3gGCgTdLEjwu0j0llYH7NAk8oU5KIZyMrGTDa xU8ou+PE7Hw8IjLv9dyB+hxXwQngY+1i+Ioz1CMmAr4QR9KqCjMOtErZW426EoDG0n ZWwH3Jx6nAAnd11/pOFJY9vSHUNoDTRFu1AngsTYsvE2korQlJDZmaQT6CsbPoIwr5 yzi1Mp+MivvdfbKoUGQsKHXEJT583q7JL2Znk9lwUlXiHrruB3lltIK3NLWFk4pDhE SzPy2Mk286CAw== From: SeongJae Park To: Andrew Morton Cc: SeongJae Park , damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 3/3] mm/damon/sysfs-schemes: handle tried region directory allocation failure Date: Mon, 6 Nov 2023 23:34:08 +0000 Message-Id: <20231106233408.51159-4-sj@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231106233408.51159-1-sj@kernel.org> References: <20231106233408.51159-1-sj@kernel.org> 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" DAMON sysfs interface's before_damos_apply callback (damon_sysfs_before_damos_apply()), which creates the DAMOS tried regions for each DAMOS action applied region, is not handling the allocation failure for the sysfs directory data. As a result, NULL pointer derefeence is possible. Fix it by handling the case. Fixes: f1d13cacabe1 ("mm/damon/sysfs: implement DAMOS tried regions update = command") Cc: # 6.2.x Signed-off-by: SeongJae Park --- mm/damon/sysfs-schemes.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c index 7413cb35c5a9..be667236b8e6 100644 --- a/mm/damon/sysfs-schemes.c +++ b/mm/damon/sysfs-schemes.c @@ -1826,6 +1826,8 @@ static int damon_sysfs_before_damos_apply(struct damo= n_ctx *ctx, return 0; =20 region =3D damon_sysfs_scheme_region_alloc(r); + if (!region) + return 0; list_add_tail(®ion->list, &sysfs_regions->regions_list); sysfs_regions->nr_regions++; if (kobject_init_and_add(®ion->kobj, --=20 2.34.1