From patchwork Mon Aug 28 21:34:59 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 9926371 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 652D960383 for ; Mon, 28 Aug 2017 21:55:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 598CC287C6 for ; Mon, 28 Aug 2017 21:55:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4E3F7287E3; Mon, 28 Aug 2017 21:55:01 +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 49664287C6 for ; Mon, 28 Aug 2017 21:54:59 +0000 (UTC) Received: (qmail 1476 invoked by uid 550); 28 Aug 2017 21:54:04 -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 1444 invoked from network); 28 Aug 2017 21:54:03 -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=vKfuE39oRowkSMb/NiZvwkS87PtPwcvGBmZDLcIcfdE=; b=KkY9e0sSqOPeuKIJOJa++6VzpJIYNj7lFK1f6KiPlzqLsmvsmJ2/cDCxOHdyBA6gNp LaRuK/b2/N/pmuooAtel6rO3qAt6daKTJvXimqs4h9Suq7V9IfqJlP7KGTywJr8rbmzh BNgMfJ6v6h1Gpoe6s4SlIokThw8439OM/Gn6w= 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=vKfuE39oRowkSMb/NiZvwkS87PtPwcvGBmZDLcIcfdE=; b=TqRW7GCMGZYzkxOIj4FDqzgHbITTC+4eWUclrCyVqAVGYJL89UucfoNgtbDF4KBB2v 4b6krFerKiA5G1VYigQh8vP2oEiQu+cyv0pA3rjCxMVZIyKQRU0b2WiIiMCoHZQDMY1D L52nIyUGfTHFMU2qJ67OpyaRWMK6k0Okf0HU48UQBXaC+rNm4sTeHJMGss+RhtrOuYX0 QRoH99YUBwK7Vw1MoVxs8SpKa1Hr+dLN5egjwbVP6pCagT/LOtcmOT9frM32CsbYd8ss +Cm0VCMKN0jWjC6iXDWhC7CrHpU5zPkMz1a+AWC8lsyqA7qTektpAfCrkFhR7ZN2zwt+ 5npw== X-Gm-Message-State: AHYfb5gRgNHgdVJaZanaglsLV0WMZBbt1PqmiRoJAEK6zvO1xPq8CYl+ XiD+kZIYGTjOmTIA X-Received: by 10.99.6.68 with SMTP id 65mr1909146pgg.328.1503957231686; Mon, 28 Aug 2017 14:53:51 -0700 (PDT) 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, linux-mm@kvack.org, kernel-hardening@lists.openwall.com Date: Mon, 28 Aug 2017 14:34:59 -0700 Message-Id: <1503956111-36652-19-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 18/30] 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 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 7c0632c7e870..170d5b2dbcb6 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1106,6 +1106,8 @@ struct proto { struct kmem_cache *slab; unsigned int obj_size; int 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 ac2a404c73eb..02dab98ca3e3 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -3109,8 +3109,12 @@ 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) {