From patchwork Mon Aug 28 21:35:03 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 9926321 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 0BA3E60375 for ; Mon, 28 Aug 2017 21:44:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 003E9283C7 for ; Mon, 28 Aug 2017 21:44:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E91FD2855D; Mon, 28 Aug 2017 21:44:31 +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 1138A283C7 for ; Mon, 28 Aug 2017 21:44:30 +0000 (UTC) Received: (qmail 9272 invoked by uid 550); 28 Aug 2017 21:44:05 -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 8138 invoked from network); 28 Aug 2017 21:44:03 -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=9cyBftQfPqK7PDY8LWTFN/JFh3fIaaX1WPYrgMl9lFo=; b=inUPgrhFrQe9FFzy/s7DuqBpL7b9u9IOC7YvzWKS2LRhp2h7wBfqWbsSfUs/StH/9L xPhCCKMaBikNPP/leGVZsAkhTnvDt9daJXYJDSMRmppjTLwMQcGi+iuhIoYLsLc0Plzt j6ZM3lcDA+tEwZvnkFZnQlSWL3ILH9IYsbbdE= 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=9cyBftQfPqK7PDY8LWTFN/JFh3fIaaX1WPYrgMl9lFo=; b=Bx4uhBJ8sQje61Pb5FVvVD6ZXD1cu/KgdSUAt6XNpn42BxDjqEFjpL6jjXlyQNGwn/ vGGIjkRJ2NeeZe88HBWQbyY5JM6CM7IM8knoTMOOrg+tiF7Or+PMgT6yP43tEp1ERgUo oLYbzy0CgQENEk4Q7JPtIKwH+csAzvs3ORAhz5/6dY7mJXC5ErM615aXQPUWtoCQa9Ne OEobQ8lATtm04dEfyL7o29c2wP36piHLqJ1EylFSJSzxys5h+UfCkvUXEWx/wZnfAN2P ngj3IoITzyLHFMGpO55ChtEm1xWbRuaYjt613jGqRSw3vorlcfRvimGYXCjlJYccoHxe 9svg== X-Gm-Message-State: AHYfb5hPeo2lCC9/1hb7MhIdv5mVxyeXCW9zlGj9swfz/153H+H9utP0 zoy1nu69Ir9I0iJG X-Received: by 10.84.254.7 with SMTP id b7mr2386319plm.292.1503956631339; Mon, 28 Aug 2017 14:43:51 -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-mm@kvack.org, kernel-hardening@lists.openwall.com Date: Mon, 28 Aug 2017 14:35:03 -0700 Message-Id: <1503956111-36652-23-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1503956111-36652-1-git-send-email-keescook@chromium.org> References: <1503956111-36652-1-git-send-email-keescook@chromium.org> Subject: [kernel-hardening] [PATCH v2 22/30] 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 c8784cb216e4..a29e41e19d64 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -4882,7 +4882,7 @@ 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; }