From patchwork Mon Jun 19 23:36:30 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 9798071 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 30D04603F5 for ; Mon, 19 Jun 2017 23:39:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2E10926C9B for ; Mon, 19 Jun 2017 23:39:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 22CD627DCD; Mon, 19 Jun 2017 23:39:45 +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 7AFFF26C9B for ; Mon, 19 Jun 2017 23:39:35 +0000 (UTC) Received: (qmail 15823 invoked by uid 550); 19 Jun 2017 23:37:29 -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 11965 invoked from network); 19 Jun 2017 23:37:07 -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=uUPxsoBcIZhPMArG3+yushaLp08WVt2QT0xoMnXD2BA=; b=FmsEXIHV9EulpxowqKBpdlwASk1iqKLqJe4dcl9ouHeel29i28EvA1uXWBhjKv5RM4 5F10R7v3Kh6sVVsutlKa2kKB3NgdhtHvgpHEXhLKDNBYNTzJTUSOVAU33GRFRlS0ui4N k/CzsgzEVB3hPd1k/deJ+CDBXIE+ze5Gs4Hs8= 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=uUPxsoBcIZhPMArG3+yushaLp08WVt2QT0xoMnXD2BA=; b=GtHnfJEST4Z1Tm4umYdXwi4i3+MdZ+XFNPdeyvMay+zCT+bCmNHnq3I7E7A6y75cGB UwvF1U2YJ+XCMZT/w5fRNGCNRXm5VXXW1HrvJW5sOmPO4w4LzY1vI2/OR6HyaGfTEu2t CCeWgYEBnkp4lcwLadWfYlko+FVviKPywIFK9fWUqe243s/yGgWYNacajrc8SLusPM9Q tmz0xCyIDOxUnDF5UUEeISAj7rYc1tsJeT+8nx7fL/JxlKPHtiqugYZ7xxZPf5AP5X6C TWlbRhWR5H9yrQYEkvptKhQMzzBiOdKop4ZXwtnW7bbxryg59l97xFoBK3ck+VrR836L 8J/w== X-Gm-Message-State: AKS2vOw9WOK6beV8jtpAJwGi5SHFntkqHTDvoNrsC6yaZFGX1QSt+kt2 Ce8Op7CCEByj0du4OiRKJw== X-Received: by 10.84.216.28 with SMTP id m28mr28914611pli.275.1497915415811; Mon, 19 Jun 2017 16:36:55 -0700 (PDT) From: Kees Cook To: kernel-hardening@lists.openwall.com Cc: Kees Cook , David Windsor , linux-mm@kvack.org, linux-kernel@vger.kernel.org Date: Mon, 19 Jun 2017 16:36:30 -0700 Message-Id: <1497915397-93805-17-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1497915397-93805-1-git-send-email-keescook@chromium.org> References: <1497915397-93805-1-git-send-email-keescook@chromium.org> Subject: [kernel-hardening] [PATCH 16/23] net: 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] 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 0defc0c76552..e94c141bcf82 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -4883,7 +4883,7 @@ 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; }