From patchwork Thu Jan 11 02:02:47 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 10156523 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 0B2F9605BA for ; Thu, 11 Jan 2018 02:08:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EED4C2870F for ; Thu, 11 Jan 2018 02:08:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E22E728711; Thu, 11 Jan 2018 02:08:00 +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 1F2E82870F for ; Thu, 11 Jan 2018 02:07:58 +0000 (UTC) Received: (qmail 31748 invoked by uid 550); 11 Jan 2018 02:04:04 -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 30311 invoked from network); 11 Jan 2018 02:03:49 -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=kiBefoTT8t3qM6vdFFK2Tc8DgtTZngbYl1PRYrfc85uQ1CV2Y8egh+13zeJDybUrcH 0xSlqrPiGO0HgvH4unRMD8lJWFgjMHGi1sWAuBwRdWF798QToyIB5mGdS01s4IE0cD6j PCsdewONvMkoKKIkHbrsFLKIk1USQwfz01J0k= 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=c1m4dplMoG2hMnM6n6BuckkGQYYLeuIlo5fe3+Rdj3weZymguvP3B6jqCKppgTH3tn lg6RX9gGulNfCzJPRGgKFk3GbPVAUQE4GgWo5c4xcqHH5iDNUe6t3TvlWJu1Eq6fg7wD aWz7irgFzLzBV2rhYBr+TQ29InuHZp2ofKriqMwOGbGIk4/mV0jMYyts8jLN4r9gNYcz XObZlncdxr9b7V2REUo/MQJY4mhkCjJpk6rmXkPbMq6rp15ayDGTu82zCgprDIilJXjD TrVVr/wQNGcPjAKTGB5c6MGTcTjNY8ShVIK0NUoFgH/4lEqRGeW7xqTbRebhRHNdS14C osYg== X-Gm-Message-State: AKGB3mKCwsQd2MCDFriud/LWuuGJ6MXelICkYKsinP3/7V7VjtuT0iC0 dijv8VU1/ROT3dw9+zsylwiXfg== X-Google-Smtp-Source: ACJfBovws6UraliYDbuC/sAmr3bojYhs9EIoOm4Y6ejanomXIEJkUygcYR5GIZ89Kq+vJpVWoi5G3Q== X-Received: by 10.84.132.97 with SMTP id 88mr20652917ple.57.1515636217356; Wed, 10 Jan 2018 18:03:37 -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: Wed, 10 Jan 2018 18:02:47 -0800 Message-Id: <1515636190-24061-16-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 15/38] 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;