From patchwork Tue Jan 9 20:55:41 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 10153441 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 35FBA60223 for ; Tue, 9 Jan 2018 21:05:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2CEE02040D for ; Tue, 9 Jan 2018 21:05:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 210042434C; Tue, 9 Jan 2018 21:05:15 +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 12DF62040D for ; Tue, 9 Jan 2018 21:05:13 +0000 (UTC) Received: (qmail 11366 invoked by uid 550); 9 Jan 2018 20:57:58 -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 9540 invoked from network); 9 Jan 2018 20:57:31 -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=N+1YJFvHTPQOoWtwEI/exfP7oTpaenyjsc66TPEbm20=; b=OfjPBljp71DVlrhgoI4oAXooIvcRdSD/0WoALCno6mpimo1pakItdoOFeO0JSGGQUs 3fkxXqGfW8I3G30VT8mhKt7m7akjN5aQ8xT0Dtz8u5KBTGCyYNJ7n5RHq0b7tZtAyqrN pTemHjzVPqsqZ1YLxQ7cfFKgjIBX/Dl6zMd34= 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=N+1YJFvHTPQOoWtwEI/exfP7oTpaenyjsc66TPEbm20=; b=o6/yzFKqS4v9v62eUmO1qKqK3Wo7T8Ep+s9wbnY5Mm3CzWbqMEFlQ0SeRHH8sJpz8E v+QDyu1qLPYxptZ8F6dSCuAAoCE/yvh4s0lRBFD9jiYGXxS+hSASkSL8Vq30n2fYeBrZ AOu3s359EHbIqVHFxXsdXXNyIDvUCMW92YqQnHKvmOhK0ajhdj5m6NE4eiaFVR/779Kh agepNXTSs9H9IiOQ4g8zRvlVVCmdqGA8lMS2O9QO2voqTyoUrnRx/jbfmIQosZWnydtu k6of4yu1hBZlyQa183BwbgOFIoWxD3w2iSwvQrxp4h2/zgBwNgmNRjNDAumRwj+Zb55o NPZg== X-Gm-Message-State: AKGB3mI8DWXlR2FJ4fm5wVWr4CfrREbBNJfVQ86INqXvtX7z6x+jNTY2 S/qfxJbHAaJBkv3bMc45G7qirA== X-Google-Smtp-Source: ACJfBovpyJlTcuCD8U/FiqvHoikW96YfY29iXe5SePWQbRC5OlV2cyzWfl7mWUmPuZalXZT2KsF/EA== X-Received: by 10.84.240.197 with SMTP id l5mr17080120plt.410.1515531440204; Tue, 09 Jan 2018 12:57:20 -0800 (PST) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , David Windsor , Dave Kleikamp , jfs-discussion@lists.sourceforge.net, 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 12:55:41 -0800 Message-Id: <1515531365-37423-13-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 12/36] jfs: Define usercopy region in jfs_ip slab cache X-Virus-Scanned: ClamAV using ClamSMTP From: David Windsor The jfs symlink pathnames, stored in struct jfs_inode_info.i_inline and therefore contained in the jfs_ip slab cache, need to be copied to/from userspace. cache object allocation: fs/jfs/super.c: jfs_alloc_inode(...): ... jfs_inode = kmem_cache_alloc(jfs_inode_cachep, GFP_NOFS); ... return &jfs_inode->vfs_inode; fs/jfs/jfs_incore.h: JFS_IP(struct inode *inode): return container_of(inode, struct jfs_inode_info, vfs_inode); fs/jfs/inode.c: jfs_iget(...): ... inode->i_link = JFS_IP(inode)->i_inline; 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 jfs_ip 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: Dave Kleikamp Cc: jfs-discussion@lists.sourceforge.net Signed-off-by: Kees Cook Acked-by: Dave Kleikamp --- fs/jfs/super.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/fs/jfs/super.c b/fs/jfs/super.c index 90373aebfdca..1b9264fd54b6 100644 --- a/fs/jfs/super.c +++ b/fs/jfs/super.c @@ -965,9 +965,11 @@ static int __init init_jfs_fs(void) int rc; jfs_inode_cachep = - kmem_cache_create("jfs_ip", sizeof(struct jfs_inode_info), 0, - SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|SLAB_ACCOUNT, - init_once); + kmem_cache_create_usercopy("jfs_ip", sizeof(struct jfs_inode_info), + 0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|SLAB_ACCOUNT, + offsetof(struct jfs_inode_info, i_inline), + sizeof_field(struct jfs_inode_info, i_inline), + init_once); if (jfs_inode_cachep == NULL) return -ENOMEM;