From patchwork Mon Aug 28 21:34:53 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 9926265 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 766A060383 for ; Mon, 28 Aug 2017 21:37:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 69003287D4 for ; Mon, 28 Aug 2017 21:37:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5DC18287DA; Mon, 28 Aug 2017 21:37:56 +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 F0AD1287E6 for ; Mon, 28 Aug 2017 21:37:54 +0000 (UTC) Received: (qmail 13414 invoked by uid 550); 28 Aug 2017 21:35:42 -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 12198 invoked from network); 28 Aug 2017 21:35:37 -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=4ulHljyu5wL7PqZ0N3kvuZDBvOrJEr5RqSokxtQVUqU=; b=BEMLUd/JlUrL7sStOlz79W27RZs+4EZ+co/q6NK/yeDNTHOUhyRbpNSt4JBm53y46a jcc98tc6hn1CdNy2p3ROYKqTaMm2MizBFqhyUCOmPi6VR2HrbaEtMjGZr5LNqmxDniVi EW0ihBpWBr7gKsjMAAYAoe6P+O2y8gPjcKF+E= 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=4ulHljyu5wL7PqZ0N3kvuZDBvOrJEr5RqSokxtQVUqU=; b=nihD+RBZRSaE/7aPHFE8FrjU7p0+incGgdGkJ4zR7xd03t5ymBlxij//tZ+p4K3G4J E3MRTpsxe8DnVxPkJKMGf/ulRL6E0DKXFJl1wWVeXPYTgUfpOD3FjbbchEnvyOeSQxsO tXD7RKFR5YMVKjG9onxbEw2d/cKbEewMsDHVdTligmOcYUQ1xxpaJAQ0dluQaDrwUbBL kCro7PJYbLWhmPSsXLmB7MswwtUSXY0ZQemTCOwCXOYJbxTDa0OkwAo8HviErUhHKko2 5VRo0lUtpQd20NNgJZjxXBKxp4hTuHTWZ2bJV0TtHYmXm/pVfQIu3/2Jn0uhYF5Fc9sJ zBkg== X-Gm-Message-State: AHYfb5jLq/BfwUgfisVHCzcXl34gZfDK+/jxC7UshnOjaMoU3G0iY876 CnLeKeAmLY5NoIRKa7JOGw== X-Received: by 10.99.51.198 with SMTP id z189mr1802127pgz.391.1503956124960; Mon, 28 Aug 2017 14:35:24 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , David Windsor , Mike Marshall , linux-mm@kvack.org, kernel-hardening@lists.openwall.com Date: Mon, 28 Aug 2017 14:34:53 -0700 Message-Id: <1503956111-36652-13-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 12/30] orangefs: Define usercopy region in orangefs_inode_cache slab cache X-Virus-Scanned: ClamAV using ClamSMTP From: David Windsor orangefs symlink pathnames, stored in struct orangefs_inode_s.link_target and therefore contained in the orangefs_inode_cache, need to be copied to/from userspace. cache object allocation: fs/orangefs/super.c: orangefs_alloc_inode(...): ... orangefs_inode = kmem_cache_alloc(orangefs_inode_cache, ...); ... return &orangefs_inode->vfs_inode; fs/orangefs/orangefs-utils.c: exofs_symlink(...): ... inode->i_link = orangefs_inode->link_target; example usage trace: readlink_copy+0x43/0x70 vfs_readlink+0x62/0x110 SyS_readlinkat+0x100/0x130 fs/namei.c: readlink_copy(..., link): ... copy_to_user(..., link, len); (inlined in vfs_readlink) generic_readlink(dentry, ...): struct inode *inode = d_inode(dentry); const char *link = inode->i_link; ... readlink_copy(..., link); In support of usercopy hardening, this patch defines a region in the orangefs_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, provide usage trace] Cc: Mike Marshall Signed-off-by: Kees Cook --- fs/orangefs/super.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/fs/orangefs/super.c b/fs/orangefs/super.c index 5a1bed6c8c6a..c67b91239730 100644 --- a/fs/orangefs/super.c +++ b/fs/orangefs/super.c @@ -626,11 +626,16 @@ void orangefs_kill_sb(struct super_block *sb) int orangefs_inode_cache_initialize(void) { - orangefs_inode_cache = kmem_cache_create("orangefs_inode_cache", - sizeof(struct orangefs_inode_s), - 0, - ORANGEFS_CACHE_CREATE_FLAGS, - orangefs_inode_cache_ctor); + orangefs_inode_cache = kmem_cache_create_usercopy( + "orangefs_inode_cache", + sizeof(struct orangefs_inode_s), + 0, + ORANGEFS_CACHE_CREATE_FLAGS, + offsetof(struct orangefs_inode_s, + link_target), + sizeof_field(struct orangefs_inode_s, + link_target), + orangefs_inode_cache_ctor); if (!orangefs_inode_cache) { gossip_err("Cannot create orangefs_inode_cache\n");