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: 9962469 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 6604960208 for ; Wed, 20 Sep 2017 20:49:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 59D232922C for ; Wed, 20 Sep 2017 20:49:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4E87A2922E; Wed, 20 Sep 2017 20:49:38 +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=-2.4 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED, T_DKIM_INVALID, URIBL_BLACK autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 6334D2922C for ; Wed, 20 Sep 2017 20:49:37 +0000 (UTC) Received: (qmail 5285 invoked by uid 550); 20 Sep 2017 20:46:38 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 3764 invoked from network); 20 Sep 2017 20:46:27 -0000 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=tHhKWj8pqYOlpm/bcU+xZN2eMzJWQnJnE39FhMJ+rer/fDWS7zg8UIo6oPo+rjE0W2 9ITdqZugUzI3km5u3RLjzFxVglBZaAJynF2qwmVcnQp2ZkXV9vO2tpONesNnGdkEtoSQ qod96Rq/OIkrD1PfZlMyGrFy9AcLUNZKKL6GZDkB8SqsQC34l2guClE7CHex59k8LLEI 3X+rXgSH0jYxvszq9hXKOvzq+Ovt6DuG5RCntmGVOL+HWo/fBTC6B3M/I5ODmUCMqjgZ SRcXvKy+1rV3kaFzE9i79wW6QXW8cnhOT3Rbgxnr2M19BITooeYMOtGCbrnXn9SFGDJz lLzg== X-Gm-Message-State: AHPjjUg62nL9oYsrxhHMrHnmW7ErWAiwxFFQd/Xc9mKyWWSCoHUokvXn GE1BzKJLLQyX4RK0i05ZTTQ75A== 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) 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 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> Subject: [kernel-hardening] [PATCH v3 22/31] sctp: Copy struct sctp_sock.autoclose to userspace using put_user() 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; }