From patchwork Mon Jun 24 14:32:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 11013357 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id BF0931580 for ; Mon, 24 Jun 2019 14:33:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AFE8428BF4 for ; Mon, 24 Jun 2019 14:33:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A36C628BE4; Mon, 24 Jun 2019 14:33:34 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.5 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3379328BF8 for ; Mon, 24 Jun 2019 14:33:34 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D7A418E000E; Mon, 24 Jun 2019 10:33:27 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id D27888E0002; Mon, 24 Jun 2019 10:33:27 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C19488E000E; Mon, 24 Jun 2019 10:33:27 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-qk1-f198.google.com (mail-qk1-f198.google.com [209.85.222.198]) by kanga.kvack.org (Postfix) with ESMTP id A002C8E0002 for ; Mon, 24 Jun 2019 10:33:27 -0400 (EDT) Received: by mail-qk1-f198.google.com with SMTP id v4so16313331qkj.10 for ; Mon, 24 Jun 2019 07:33:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:date:in-reply-to:message-id :mime-version:references:subject:from:to:cc; bh=hgUbj0aIma7FN/fDppNoJ1F9osla3F1YuX2112+Mp8s=; b=Aix0LgRLH4e2d/fa5JH/b6AnNiSTOx6Vr1SSSolwzR3BOV/5T/R6+QhZQRRtXeAZnv DIDcR0XVbuqZYo+u1/rd+Dt8BAJDLk1gpbEKQrbxMhoPxsXCqn2pbuK+4lEopl7Vd3Ou UaJsRR9PmSYEv9gg9o1PHnxzactUqpYmSCwQ3YU+/JfgTGMPfYB7kPBti8nNxJRSfnND eQ0JtX043Ec/N41IfaYVpvyezK1GsEbYUu2yDbz1U+DzsIByr2fcL7XC11Gop+MtEjkl B7BWn4mRticoVWgAW8ReZPhlEsv+FVzzsbQnoqBmRxTZqE/FppS9oA/KvDe8FVQ2vTrP Jhpw== X-Gm-Message-State: APjAAAWuovCLcHH9kOI3ACjg17Hl2emZaJjsDidt/AglpTVCd9qijoEB /+o72zSV/zt4em0nWy37Z7p2rn7s2qwqWR26Cee/DqnoQmvhTLiVZmaTFpD/IVtm3Sz7KWrOKdP Cb3q9jCoj3VHN2XYlYcqfJ81lbeV4H7SETN2TGMqakF4xSH3+tajxsVjFuE07dCkyrA== X-Received: by 2002:ac8:32e9:: with SMTP id a38mr133350779qtb.245.1561386807423; Mon, 24 Jun 2019 07:33:27 -0700 (PDT) X-Received: by 2002:ac8:32e9:: with SMTP id a38mr133350738qtb.245.1561386806884; Mon, 24 Jun 2019 07:33:26 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1561386806; cv=none; d=google.com; s=arc-20160816; b=SrIAkDAxztca1n6m4OaBBbav1/RkUQXYEkBB0yiXi2zCsDOH/UihbXNuCKkHU1DE6t 58tvlSWJmmY0tijysZpNzHqnwVyD85G8MsIN/fKLRExqPruuhdeWVtFl3D/AbQRKUWrI Inje/NDieFvnCkG3wUDuBCGxNGUEHiZtF0HqW43BVMRWcZ6uo0iriGF+bHNqFQOKH+eH TUMoz3VpCE6P8bluVmT6SFVisc8PmWSs4/GBp2qzS7mImy9k3UTEU+V0r3gUkVaMsZ/z Z5SqpDu7zvCAwoSQ7jI+jiwlbrlyInKh5JSoatBMgVYGf9rTcb3chILiWWroPYbG9L/X 16mA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:dkim-signature; bh=hgUbj0aIma7FN/fDppNoJ1F9osla3F1YuX2112+Mp8s=; b=mynXjsEP4gSSLzubEESvlJodxXgjb+uQzYw45xhJY31pFPTPZo24caHzdFqT1aUSfI HUKy6rk0OmwAF1IajLpM+WrWd1b/xILmSCDEHFWBTTVH4dbpGJGuF96g4EDu7zd6m53a nqy4wcQ3ELRD9QkQB9SGyuoMyS5Tjjzf3RkNj+g7Avc0x0xClymBkxF+IyCO5J4fcE69 bAkCpn81yR8hSZywMeXfY+v0iJsn4lGjLZ5V2qbd4lw/E+pE8UfEGvFw0BSc6sdULisT Cr3vC2hM0e6ePKwx151Yg39qxAazbcBsJVshDcGI+3/immTa3ebbLMLhB6t1eJSEC4No 7CwA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=XScBtinb; spf=pass (google.com: domain of 3nt8qxqokcccdqguhbnqyojrrjoh.frpolqxa-ppnydfn.ruj@flex--andreyknvl.bounces.google.com designates 209.85.220.73 as permitted sender) smtp.mailfrom=3Nt8QXQoKCCcDQGUHbNQYOJRRJOH.FRPOLQXa-PPNYDFN.RUJ@flex--andreyknvl.bounces.google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: from mail-sor-f73.google.com (mail-sor-f73.google.com. [209.85.220.73]) by mx.google.com with SMTPS id g28sor15558123qtb.3.2019.06.24.07.33.26 for (Google Transport Security); Mon, 24 Jun 2019 07:33:26 -0700 (PDT) Received-SPF: pass (google.com: domain of 3nt8qxqokcccdqguhbnqyojrrjoh.frpolqxa-ppnydfn.ruj@flex--andreyknvl.bounces.google.com designates 209.85.220.73 as permitted sender) client-ip=209.85.220.73; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=XScBtinb; spf=pass (google.com: domain of 3nt8qxqokcccdqguhbnqyojrrjoh.frpolqxa-ppnydfn.ruj@flex--andreyknvl.bounces.google.com designates 209.85.220.73 as permitted sender) smtp.mailfrom=3Nt8QXQoKCCcDQGUHbNQYOJRRJOH.FRPOLQXa-PPNYDFN.RUJ@flex--andreyknvl.bounces.google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=hgUbj0aIma7FN/fDppNoJ1F9osla3F1YuX2112+Mp8s=; b=XScBtinbiUGDniM5VWwPkGG4/4TOXpRMgLEipRA38wBRqrcXcDq9jBk/0BRZ6x9hlI V9LUyuozhqT/IxEnIqdvY3TfW2BBFmFPeZMV6/kHE3QjS3QjydQyEBZrtxP0iPkgc0Lq Fl63uCJcNPhGHDYzX4eXyVr2le0SZJjeeiUUJ6M7ZIcaEAu7j+hLiu/GnMRfjOmk9l2j 73WehpBOM1MSylhUeiF0hVgN+PDN+5kZdcFg4wO/LJNJCaEb2km52xgKxYMc9FCtyBPh HEL+2jGVAoHMOTxdl5nV9rz2oXMXpuOjUoFsub2nzlRgfcoGoFmp1CkWMhgLIpXXStyF WB2w== X-Google-Smtp-Source: APXvYqz02tw9mMb0OtKeZ2W98zeRoHwxKY7XE2woJy2A8vtl93nXys5C7sVpsVp2/N99zMzUyfh+KRmcoF+IJQVn X-Received: by 2002:ac8:3811:: with SMTP id q17mr99190639qtb.315.1561386806511; Mon, 24 Jun 2019 07:33:26 -0700 (PDT) Date: Mon, 24 Jun 2019 16:32:52 +0200 In-Reply-To: Message-Id: <41e0a911e4e4d533486a1468114e6878e21f9f84.1561386715.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.22.0.410.gd8fdbe21b5-goog Subject: [PATCH v18 07/15] fs/namespace: untag user pointers in copy_mount_options From: Andrey Konovalov To: linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org Cc: Catalin Marinas , Vincenzo Frascino , Will Deacon , Mark Rutland , Andrew Morton , Greg Kroah-Hartman , Kees Cook , Yishai Hadas , Felix Kuehling , Alexander Deucher , Christian Koenig , Mauro Carvalho Chehab , Jens Wiklander , Alex Williamson , Leon Romanovsky , Luc Van Oostenryck , Dave Martin , Khalid Aziz , enh , Jason Gunthorpe , Christoph Hellwig , Dmitry Vyukov , Kostya Serebryany , Evgeniy Stepanov , Lee Smith , Ramana Radhakrishnan , Jacob Bramley , Ruben Ayrapetyan , Robin Murphy , Kevin Brodsky , Szabolcs Nagy , Andrey Konovalov 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: X-Virus-Scanned: ClamAV using ClamSMTP This patch is a part of a series that extends kernel ABI to allow to pass tagged user pointers (with the top byte set to something else other than 0x00) as syscall arguments. In copy_mount_options a user address is being subtracted from TASK_SIZE. If the address is lower than TASK_SIZE, the size is calculated to not allow the exact_copy_from_user() call to cross TASK_SIZE boundary. However if the address is tagged, then the size will be calculated incorrectly. Untag the address before subtracting. Reviewed-by: Khalid Aziz Reviewed-by: Vincenzo Frascino Reviewed-by: Kees Cook Reviewed-by: Catalin Marinas Signed-off-by: Andrey Konovalov --- fs/namespace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/namespace.c b/fs/namespace.c index 7660c2749c96..ec78f7223917 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2994,7 +2994,7 @@ void *copy_mount_options(const void __user * data) * the remainder of the page. */ /* copy_from_user cannot cross TASK_SIZE ! */ - size = TASK_SIZE - (unsigned long)data; + size = TASK_SIZE - (unsigned long)untagged_addr(data); if (size > PAGE_SIZE) size = PAGE_SIZE;