From patchwork Tue Jan 9 20:55:49 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 10153345 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 CB276602CA for ; Tue, 9 Jan 2018 20:59:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BE443204C4 for ; Tue, 9 Jan 2018 20:59:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B218F24B5B; Tue, 9 Jan 2018 20:59:52 +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 8AF6F204C4 for ; Tue, 9 Jan 2018 20:59:51 +0000 (UTC) Received: (qmail 9439 invoked by uid 550); 9 Jan 2018 20:57:27 -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 8085 invoked from network); 9 Jan 2018 20:57:17 -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=LFWRCd/+LnQ+jgsEC7h8LYDXfoIkGuadoUBcvax4iD0=; b=WGvgPWnYDmGsg51iCwuntkZZugWRwv6oZLzMmMzQXI9BbfvnYgognLlbZt1IWZeTZt erT9plGzVT8XkV48RXqU2GUSv+b+0EArDRv8FNSqnEzne0ssJ7XZz7iSqD6vyDi0h/nE Qh4W9woWKXUY6uHBQ+901HF9ss82CyrhsTJbs= 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=LFWRCd/+LnQ+jgsEC7h8LYDXfoIkGuadoUBcvax4iD0=; b=lWsiwNRJRT4MXkOqqhZU222xu0/XYzV0c7/q/t7esyu6cio7S1sv4RpFp3jb4Cqks4 RyeJY74Li3xeSPhTd8PISpOh8OV2UXQOb3/u6HC2dL8nnhk72IZbKnJd03aDlaSXkdev 73MAJNsIl8s7J81j02LlFnVHVq0ooh6HP+o0158xCdrBBhQCsrI0EtlP1Sqi/0KpLDK0 K2UNpiVz4TSS38q+BP0oHHJeTv1BdjA0xcRa2oJZCvRLBRTx+X1aC2WBrY9VBt2apZia SwXcxoXV9g8m8SYviJynAdqptX8Mur4hdgmQHkcYrg5/3eUPbSQUrqPHbyInAaNzfezj GCEA== X-Gm-Message-State: AKGB3mLqwaz+PvDrv5jOb0FMqdUfhQ52ETMvPsXYjPleEmu1iTLvFirI zibG7vz/pleQJB1B5ogZtEzFnA== X-Google-Smtp-Source: ACJfBosffltHV39UMVsspIIn4EYxGGsm0TddVvMWWNLE1ZDKoPYqdxC5u2GTR8IxlJYSD2BcdYb+JA== X-Received: by 10.99.42.6 with SMTP id q6mr13442957pgq.207.1515531425725; Tue, 09 Jan 2018 12:57:05 -0800 (PST) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , David Windsor , "David S. Miller" , Eric Dumazet , Paolo Abeni , David Howells , netdev@vger.kernel.org, Linus Torvalds , Alexander Viro , Andrew Morton , Andy Lutomirski , Christoph Hellwig , Christoph Lameter , Laura Abbott , Mark Rutland , "Martin K. Petersen" , Paolo Bonzini , Christian Borntraeger , Christoffer Dall , Dave Kleikamp , Jan Kara , Luis de Bethencourt , Marc Zyngier , Rik van Riel , Matthew Garrett , linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, kernel-hardening@lists.openwall.com Date: Tue, 9 Jan 2018 12:55:49 -0800 Message-Id: <1515531365-37423-21-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1515531365-37423-1-git-send-email-keescook@chromium.org> References: <1515531365-37423-1-git-send-email-keescook@chromium.org> Subject: [kernel-hardening] [PATCH 20/36] net: Define usercopy region in struct proto slab cache X-Virus-Scanned: ClamAV using ClamSMTP From: David Windsor In support of usercopy hardening, this patch defines a region in the struct proto slab cache in which userspace copy operations are allowed. Some protocols need to copy objects to/from userspace, and they can declare the region via their proto structure with the new usersize and useroffset fields. Initially, if no region is specified (usersize == 0), the entire field is marked as whitelisted. This allows protocols to be whitelisted in subsequent patches. Once all protocols have been annotated, the full-whitelist default can be removed. This region is known as the slab cache's usercopy region. Slab caches can now check that each dynamically sized copy operation involving cache-managed memory falls entirely within the slab's usercopy region. This patch is modified 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, split off per-proto patches] [kees: add logic for by-default full-whitelist] Cc: "David S. Miller" Cc: Eric Dumazet Cc: Paolo Abeni Cc: David Howells Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook --- include/net/sock.h | 2 ++ net/core/sock.c | 6 +++++- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/include/net/sock.h b/include/net/sock.h index 79e1a2c7912c..b77a710ee831 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1112,6 +1112,8 @@ struct proto { struct kmem_cache *slab; unsigned int obj_size; slab_flags_t slab_flags; + size_t useroffset; /* Usercopy region offset */ + size_t usersize; /* Usercopy region size */ struct percpu_counter *orphan_count; diff --git a/net/core/sock.c b/net/core/sock.c index c0b5b2f17412..261e6dbf0259 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -3151,8 +3151,12 @@ static int req_prot_init(const struct proto *prot) int proto_register(struct proto *prot, int alloc_slab) { if (alloc_slab) { - prot->slab = kmem_cache_create(prot->name, prot->obj_size, 0, + prot->slab = kmem_cache_create_usercopy(prot->name, + prot->obj_size, 0, SLAB_HWCACHE_ALIGN | prot->slab_flags, + prot->usersize ? prot->useroffset : 0, + prot->usersize ? prot->usersize + : prot->obj_size, NULL); if (prot->slab == NULL) {