From patchwork Wed Sep 20 20:45:28 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 9962431 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8412260208 for ; Wed, 20 Sep 2017 20:47:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 77BF629226 for ; Wed, 20 Sep 2017 20:47:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6C48729229; Wed, 20 Sep 2017 20:47:50 +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=-4.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM, URIBL_BLACK autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0A34E29226 for ; Wed, 20 Sep 2017 20:47:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752010AbdITUqz (ORCPT ); Wed, 20 Sep 2017 16:46:55 -0400 Received: from mail-pg0-f46.google.com ([74.125.83.46]:56527 "EHLO mail-pg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751945AbdITUqQ (ORCPT ); Wed, 20 Sep 2017 16:46:16 -0400 Received: by mail-pg0-f46.google.com with SMTP id 7so2323982pgd.13 for ; Wed, 20 Sep 2017 13:46:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=hS3AC84FoHkASZGLNsNZedW+0T2lp4pqYCvFt8TS/VA=; b=QDdfAFVA+EGn5K99o+iLHU2x0TgfylgKtt4TTXRbyCw3kRunAZXwJYYPBiMnX/K3xO c2UH4SvSrg9GNLiQyMmeXrAOQyCyey+7oXvWpVyTgItVxw0rc4vsymn/+yAnw++6b6qL +Fc2OLrrDGBMYnG0GnPATDDxiAPSXCg8X9B8I= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=hS3AC84FoHkASZGLNsNZedW+0T2lp4pqYCvFt8TS/VA=; b=d0bmvrrjSvZKBX12vA29u5NbPVdekzUFp5jwO6Lxc9yfkWEt2mPjB/wbj7UXnrdsMf o/N3s4W7QGW0mJ6u3H8twITcwGku/1ktUlvc+bwz8M7thT05a9pQNbXTLRfWDP5vYrm9 zE18T1H4O6C7OPUYEeZmGdM7hn17SRx5njRWX6mQveTXzQHFYhQh1S9gglbydihTqqdV n5tCb+71c5e4y0FSfNHyTI7V692xt0axffgRhmMgSoqf71kKvpgjC1zlPJpUg4Ws1qqK LQ36oDnZI5sJz0esFnPeXzZyiASB3pUkk5ZULPv5Lf071XIDX7Wtvj7FKg0Z3teHp31g z4rA== X-Gm-Message-State: AHPjjUj3nlgfLSDvLUaRzaG0N6K9n+y+Y8gkKmirZkdB7RlU5M8sD8Ap c8sclUy4HeSFqk+X0BSqxed8C+XsE7s= X-Google-Smtp-Source: AOwi7QCeaV39ApqN5/uDadByIfJoBIZO0h6zwAzrkO/+0n3gzWBaSZaviVqrhFHp4NCVNd2vhdy7hQ== X-Received: by 10.98.25.193 with SMTP id 184mr3405549pfz.24.1505940375733; Wed, 20 Sep 2017 13:46:15 -0700 (PDT) Received: from www.outflux.net (173-164-112-133-Oregon.hfc.comcastbusiness.net. [173.164.112.133]) by smtp.gmail.com with ESMTPSA id s68sm10988374pfd.72.2017.09.20.13.46.05 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 20 Sep 2017 13:46:09 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , David Windsor , Vlad Yasevich , Neil Horman , "David S. Miller" , linux-sctp@vger.kernel.org, netdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, kernel-hardening@lists.openwall.com Subject: [PATCH v3 22/31] sctp: Copy struct sctp_sock.autoclose to userspace using put_user() Date: Wed, 20 Sep 2017 13:45:28 -0700 Message-Id: <1505940337-79069-23-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1505940337-79069-1-git-send-email-keescook@chromium.org> References: <1505940337-79069-1-git-send-email-keescook@chromium.org> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: David Windsor The autoclose field can be copied with put_user(), so there is no need to use copy_to_user(). In both cases, hardened usercopy is being bypassed since the size is constant, and not open to runtime manipulation. This patch is verbatim from Brad Spengler/PaX Team's PAX_USERCOPY whitelisting code in the last public patch of grsecurity/PaX based on my understanding of the code. Changes or omissions from the original code are mine and don't reflect the original grsecurity/PaX code. Signed-off-by: David Windsor [kees: adjust commit log] Cc: Vlad Yasevich Cc: Neil Horman Cc: "David S. Miller" Cc: linux-sctp@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook --- net/sctp/socket.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index aa4f86d64545..e070c0934638 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -4893,7 +4893,7 @@ static int sctp_getsockopt_autoclose(struct sock *sk, int len, char __user *optv len = sizeof(int); if (put_user(len, optlen)) return -EFAULT; - if (copy_to_user(optval, &sctp_sk(sk)->autoclose, sizeof(int))) + if (put_user(sctp_sk(sk)->autoclose, (int __user *)optval)) return -EFAULT; return 0; }