From patchwork Thu Jan 11 02:02:51 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 10156543 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 70A3E605BA for ; Thu, 11 Jan 2018 02:09:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5E44B2872D for ; Thu, 11 Jan 2018 02:09:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 511042872F; Thu, 11 Jan 2018 02:09:50 +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 737052872D for ; Thu, 11 Jan 2018 02:09:49 +0000 (UTC) Received: (qmail 28299 invoked by uid 550); 11 Jan 2018 02:09:47 -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 28277 invoked from network); 11 Jan 2018 02:09:46 -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=ArY4mmJZq2qSxtBfA5c8RBIOZN8HYA220FFpy+yyeoY=; b=joxRcjlAuVkljo1F2+IgULHQHU8A9suC139M46vfOXRQslWwrsatJRj/rDmanRZVK5 0TMdKKibs5hK2MvWVsFVamrgqrPKzq76nXqrgSqqT6yL548kN1DH4hRvE3At+kHlcfQq fozgkVywzgnhx2Rr1BnArbqje1KT+DKqsiwt4= 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=ArY4mmJZq2qSxtBfA5c8RBIOZN8HYA220FFpy+yyeoY=; b=lUVfJLfWOgAlWBnHa1VK84K3seFvuuevvBGb9qQsiRezQ0CsQddx+v76GQn8BJbSfI Hrtuq+IlIMvfcqOMWakx4l+LUEARNvX4GHdTz8LxqPuXxHpsWAO6CYAeF4qKUD7sJTvY lWLSNcH0jtN2qp0limA8vud1MsgKxKMjLHS0aTRQ9XBCj02GDTwJlam8JL7D91mCZRKS SWp36VYgIKYsAx2eknMrJaMkPluIBZ2dLE8fclZHYm0KSe+Buwkhv3L3FQk1aJ+jTp5C S7m/Th3EE/cbKhG0lNAdOsvzQYYTHzIA/ZWgtvzGup2etmekXdKsWUHnwD734EcDHg4K 1EqA== X-Gm-Message-State: AKGB3mIfL4YH4w4/1OB+VC6xYYAC7N3sqHhVxsIgyIGGz1fQZkxmMNn6 qOluiaTGwBxfCrys16uCUQbB0g== X-Google-Smtp-Source: ACJfBosVS8b/v4NQsaAVsN4PT/Pv2EhQkwX8ebS+qqbGlHJLLilZt/+z6BndT/IW4QdIqWzr/5/BaA== X-Received: by 10.84.244.72 with SMTP id e8mr15849355plt.420.1515636574790; Wed, 10 Jan 2018 18:09:34 -0800 (PST) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , David Windsor , Evgeniy Dushistov , 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: Wed, 10 Jan 2018 18:02:51 -0800 Message-Id: <1515636190-24061-20-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1515636190-24061-1-git-send-email-keescook@chromium.org> References: <1515636190-24061-1-git-send-email-keescook@chromium.org> Subject: [kernel-hardening] [PATCH 19/38] ufs: Define usercopy region in ufs_inode_cache slab cache X-Virus-Scanned: ClamAV using ClamSMTP From: David Windsor The ufs symlink pathnames, stored in struct ufs_inode_info.i_u1.i_symlink and therefore contained in the ufs_inode_cache slab cache, need to be copied to/from userspace. cache object allocation: fs/ufs/super.c: ufs_alloc_inode(...): ... ei = kmem_cache_alloc(ufs_inode_cachep, GFP_NOFS); ... return &ei->vfs_inode; fs/ufs/ufs.h: UFS_I(struct inode *inode): return container_of(inode, struct ufs_inode_info, vfs_inode); fs/ufs/namei.c: ufs_symlink(...): ... inode->i_link = (char *)UFS_I(inode)->i_u1.i_symlink; 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 ufs_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: Evgeniy Dushistov Signed-off-by: Kees Cook --- fs/ufs/super.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/fs/ufs/super.c b/fs/ufs/super.c index 4d497e9c6883..652a77702aec 100644 --- a/fs/ufs/super.c +++ b/fs/ufs/super.c @@ -1466,11 +1466,14 @@ static void init_once(void *foo) static int __init init_inodecache(void) { - ufs_inode_cachep = kmem_cache_create("ufs_inode_cache", - sizeof(struct ufs_inode_info), - 0, (SLAB_RECLAIM_ACCOUNT| - SLAB_MEM_SPREAD|SLAB_ACCOUNT), - init_once); + ufs_inode_cachep = kmem_cache_create_usercopy("ufs_inode_cache", + sizeof(struct ufs_inode_info), 0, + (SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD| + SLAB_ACCOUNT), + offsetof(struct ufs_inode_info, i_u1.i_symlink), + sizeof_field(struct ufs_inode_info, + i_u1.i_symlink), + init_once); if (ufs_inode_cachep == NULL) return -ENOMEM; return 0;