From patchwork Mon Jun 19 23:36:23 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 9798053 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 0DF1060381 for ; Mon, 19 Jun 2017 23:38:46 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0869126C9B for ; Mon, 19 Jun 2017 23:38:46 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EE94227F92; Mon, 19 Jun 2017 23:38:45 +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 6A2BB26C9B for ; Mon, 19 Jun 2017 23:38:43 +0000 (UTC) Received: (qmail 14153 invoked by uid 550); 19 Jun 2017 23:37:21 -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 11741 invoked from network); 19 Jun 2017 23:37:04 -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=TyBjM3XARPMIOz8vpq7pOphMHi1k+Z64Wz7GGGku+Qs=; b=RMD3XB027ZeEdY9bmTen+scKO7XG3KG7dJ3olI/U2JA3l0jICEL+S9gPPpuDAyDVds MsbM7nVkQ6W7mtFqoHCyXxv3wCt1ejtB2MnNZCkirB80HmDEoZ62yLSDJNschzyAyrcT TGvYX3kUAnIJ2yQ6mogXyxtWeMCc7ms/ZNMOk= 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=TyBjM3XARPMIOz8vpq7pOphMHi1k+Z64Wz7GGGku+Qs=; b=b/Ng9pQv1JapEnk69uK815vVsMLQpKyY7BQKM2oxa4aM7srHHKmQQ6/SQtyGSYBzPJ 6kRmgjGtRy9JaBDAh1mn0M+8G6itPADwkH+wcRcJ61toRvkVv6q/L5sBazUcXwtFdRER NqG1kQjQjmJyM1vf9iV8X++pgWQe0J/HpTV/Hc7p/wSav1mwuCB5QNrLRdIkOugEZI+T FwJh586NfZ9zB2bMPe5rcCqvyCsiTgBEB1WOMTjr7UcLLcuhrb/gEdoYx4gV6nkOdA1K 7RQ/bVrUJPcztdZqYvl1IH0Rh7Jj0yztxTglNLtQm0Gd/Qf2acr5jm1dT1BF8sHXpYmq 1iZw== X-Gm-Message-State: AKS2vOyal2+HxKAeAFrN0tMRKbxES5DsXhI1+srzac8DPsCciikJJeCc e8rQa3G0yLcp2hC6 X-Received: by 10.84.208.102 with SMTP id f35mr31891272plh.53.1497915411885; Mon, 19 Jun 2017 16:36:51 -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 16:36:23 -0700 Message-Id: <1497915397-93805-10-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 09/23] ext4: define usercopy region in ext4_inode_cache slab cache X-Virus-Scanned: ClamAV using ClamSMTP From: David Windsor The ext4 symlink pathnames, stored in struct ext4_inode_info.i_data and therefore contained in the ext4_inode_cache slab cache, need to be copied to/from userspace. In support of usercopy hardening, this patch defines a region in the ext4_inode_cache slab cache in which userspace copy operations are allowed. 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] Signed-off-by: Kees Cook --- fs/ext4/super.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index d37c81f327e7..bd92123cf1fc 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1031,11 +1031,13 @@ static void init_once(void *foo) static int __init init_inodecache(void) { - ext4_inode_cachep = kmem_cache_create("ext4_inode_cache", - sizeof(struct ext4_inode_info), - 0, (SLAB_RECLAIM_ACCOUNT| - SLAB_MEM_SPREAD|SLAB_ACCOUNT), - init_once); + ext4_inode_cachep = kmem_cache_create_usercopy("ext4_inode_cache", + sizeof(struct ext4_inode_info), 0, + (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD| + SLAB_ACCOUNT), + offsetof(struct ext4_inode_info, i_data), + sizeof_field(struct ext4_inode_info, i_data), + init_once); if (ext4_inode_cachep == NULL) return -ENOMEM; return 0;