From patchwork Tue Jan 9 20:55:44 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 10153331 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 729C0602CA for ; Tue, 9 Jan 2018 20:59:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 699212040D for ; Tue, 9 Jan 2018 20:59:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5DF9324B48; Tue, 9 Jan 2018 20:59:04 +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 5A16320453 for ; Tue, 9 Jan 2018 20:59:03 +0000 (UTC) Received: (qmail 8109 invoked by uid 550); 9 Jan 2018 20:57:17 -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 8009 invoked from network); 9 Jan 2018 20:57:15 -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=cHB2F/Yz6P6r9aNJ3lpILjggOeGYjgFQ1X/Tj7q44/0=; b=KpqIQCRXHVquMJMFv0iMHJq9BODX5KftZKEqPt9cZlslZkPG3qEjA/jGVc7jWp2dTH 8mScbV4sozrMrnW7amBWeAwyIt4b+cUXC8IxtbgrZ+/lIY3jMPfsNpDrA+CRpTkNRWEM zE0iSNvYpO+R8PR1LNAq6dKxkou5Ig9AByzOU= 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=cHB2F/Yz6P6r9aNJ3lpILjggOeGYjgFQ1X/Tj7q44/0=; b=V2o/bN/dW2kDvX4pgG/RPwz1eexHXwIlNYLt0Xo7ENWhNshOGv+OFjBKdEK+b2FWUJ iq9fAzkp1+nMvD6hAKCnblcQhDVVZ9TP+QQWrrUFu9pJKwecbClu7eswDe2wSXaIJiUK KsS/2Sk9mwpUVhFwtF4HbxgDSc0RbR8IbrqcpOra+l8yo6m6yFn2bQMY/NYTr5oxowZc D7QvQ3r9UXHRLcO9N7/p19qBYPB9UFphWIMNP34KoX7M5DmpyPh5ISKtw03gc6gIKtaM olEbZwi74JvVx/oGRrYO9Xu7vmQHzZaH0SMMx9J43CQuUgx/pMFsjdgsMEYK5cf2b6YW hkdA== X-Gm-Message-State: AKGB3mKfoOT4O830SIUOWOw38NjxU4cawxdl0a1RbpmMZuARj/7TZo4j IoHoZI8S2sNZpkf1m9+jaKvEjA== X-Google-Smtp-Source: ACJfBouUuBDAR4AYDoF3NJyToqojrfA230tk8g2xZaZT1Pnq3YSVdcaCy1I3OZI6T7YGXi1gGGsYMA== X-Received: by 10.159.247.138 with SMTP id e10mr12329648pls.279.1515531423676; Tue, 09 Jan 2018 12:57:03 -0800 (PST) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , David Windsor , Mike Marshall , Linus Torvalds , Alexander Viro , Andrew Morton , Andy Lutomirski , Christoph Hellwig , Christoph Lameter , "David S. Miller" , 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, netdev@vger.kernel.org, linux-mm@kvack.org, kernel-hardening@lists.openwall.com Date: Tue, 9 Jan 2018 12:55:44 -0800 Message-Id: <1515531365-37423-16-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 15/36] 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 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, 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 36f1390b5ed7..62d49e53061c 100644 --- a/fs/orangefs/super.c +++ b/fs/orangefs/super.c @@ -610,11 +610,16 @@ 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");