From nobody Wed Feb 11 01:12:33 2026 Delivered-To: importer2@patchew.org Received-SPF: pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; envelope-from=linux-kernel-owner@vger.kernel.org; helo=vger.kernel.org; Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail(p=none dis=none) header.from=yandex.ru Return-Path: Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mx.zohomail.com with SMTP id 1643224926604690.507922392521; Wed, 26 Jan 2022 11:22:06 -0800 (PST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244429AbiAZTWE (ORCPT ); Wed, 26 Jan 2022 14:22:04 -0500 Received: from forward102j.mail.yandex.net ([5.45.198.243]:60028 "EHLO forward102j.mail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231542AbiAZTWD (ORCPT ); Wed, 26 Jan 2022 14:22:03 -0500 Received: from sas1-299d7dae1406.qloud-c.yandex.net (sas1-299d7dae1406.qloud-c.yandex.net [IPv6:2a02:6b8:c14:399e:0:640:299d:7dae]) by forward102j.mail.yandex.net (Yandex) with ESMTP id E2E394BE5E1D; Wed, 26 Jan 2022 22:15:06 +0300 (MSK) Received: from sas1-1f4a002bb12a.qloud-c.yandex.net (sas1-1f4a002bb12a.qloud-c.yandex.net [2a02:6b8:c14:3908:0:640:1f4a:2b]) by sas1-299d7dae1406.qloud-c.yandex.net (mxback/Yandex) with ESMTP id MRAHHasq3z-F6cmkliU; Wed, 26 Jan 2022 22:15:06 +0300 Received: by sas1-1f4a002bb12a.qloud-c.yandex.net (smtp/Yandex) with ESMTPSA id vdrU00sr04-F5IGfXk7; Wed, 26 Jan 2022 22:15:05 +0300 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (Client certificate not present) X-Greylist: delayed 411 seconds by postgrey-1.27 at vger.kernel.org; Wed, 26 Jan 2022 14:22:02 EST DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail; t=1643224506; bh=p3KfHCrgw2V7xw85Rkmv7kxdQ1h3+1sdFv87o/9OxoY=; h=In-Reply-To:References:Date:Subject:To:From:Message-Id:Cc; b=r27455zd7Uwjz5OYX65kwCLGugwbRzux9uNOj7E1EWM8eS4djUwvsuZoEUYZBr4sF 4Y6as9FbiZxl5X6QNgnqXFYwLz0VXA9CCoFwK7lE80I3suIfms8e+eFy/Mi5BjjKHa jcFEnEHPQ+dJpZ4HtsWkW8TaCoBZLWbTuhYCZIIE= Authentication-Results: sas1-299d7dae1406.qloud-c.yandex.net; dkim=pass header.i=@yandex.ru X-Yandex-Fwd: 2 From: Stas Sergeev Cc: Stas Sergeev , "Eric W. Biederman" , Kees Cook , Jens Axboe , Peter Zijlstra , Marco Elver , Thomas Gleixner , Alexey Gladkov , Andrew Lutomirski , linux-kernel@vger.kernel.org Subject: [PATCH 1/2] sigaltstack: ignore flags if SS_DISABLE is set Date: Wed, 26 Jan 2022 22:14:40 +0300 Message-Id: <20220126191441.3380389-2-stsp2@yandex.ru> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220126191441.3380389-1-stsp2@yandex.ru> References: <20220126191441.3380389-1-stsp2@yandex.ru> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZM-MESSAGEID: 1643224928374100001 Content-Type: text/plain; charset="utf-8" ss_flags combo of SS_AUTODISARM|SS_DISABLE can be used to check the support of SS_AUTODISARM. We need to remove the like flags and only keep SS_DISABLE because many libraries (eg asan runtime) check if SAS is disabled by just checking "ss_flags =3D=3D SS_DISABLE". Also man page mandates that only 1 flag can be returned, so returning SS_AUTODISARM|SS_DISABLE should be disallowed. Signed-off-by: Stas Sergeev CC: "Eric W. Biederman" CC: Kees Cook CC: Jens Axboe CC: Peter Zijlstra CC: Marco Elver CC: Thomas Gleixner CC: Alexey Gladkov CC: Andrew Lutomirski CC: linux-kernel@vger.kernel.org --- kernel/signal.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/signal.c b/kernel/signal.c index 38602738866e..40634a500317 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -4209,6 +4209,7 @@ do_sigaltstack (const stack_t *ss, stack_t *oss, unsi= gned long sp, if (ss_mode =3D=3D SS_DISABLE) { ss_size =3D 0; ss_sp =3D NULL; + ss_flags =3D SS_DISABLE; } else { if (unlikely(ss_size < min_ss_size)) ret =3D -ENOMEM; --=20 2.34.1