From patchwork Wed Sep 20 20:45:18 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 9962453 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 8191A60208 for ; Wed, 20 Sep 2017 20:48:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 73F8429226 for ; Wed, 20 Sep 2017 20:48:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 686E929229; Wed, 20 Sep 2017 20:48:51 +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 656FD29226 for ; Wed, 20 Sep 2017 20:48:50 +0000 (UTC) Received: (qmail 3909 invoked by uid 550); 20 Sep 2017 20:46:30 -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 3588 invoked from network); 20 Sep 2017 20:46:20 -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=P4SFljHEyscsVLWOjbvOMPbmz2tjOkxe1+UySbOaIdE=; b=CCiqGFNFXpENRjZbIkMhUKnMTPXfuUFlfI1F6c8TCU7/vezwFnTsBZeQg6x5+31sAJ asHPS8XaMKEY9bCo/DaX/pavTD1dAtIpBslu0Um6nmBREXzOwVGxLj1TFx2ylft9YZVi IMbviqn4MSVKXOEfehRdn9G1IEgNKuQrllNGM= 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=P4SFljHEyscsVLWOjbvOMPbmz2tjOkxe1+UySbOaIdE=; b=AmV/8+HOOW8Y4a8FoaVbBaMQ30zoSReIq19j1kXSyb8iFXkXSa3zk2AgiWVxcbIUlo yBADhZ+jWMTEC/bGJ/dYzo/ph0LKMb5P67iTJpCMOWPULZOtgEBeDn6tK9fA+qcynLZH UglnuZ6la02GbDpkYXTUGRuBo496u6f6h1KQU3EQePeBhkl1c67h/INteo47hvFQmL6/ n4xR0DgWBIimnIWgjGeSYzgLw+LB1yeoI9E9OnZWj7HBY5neE3Tn97R6rxRt6p5FAy7D D9TCEum4rdI4vob+nO7ZF2jkcSWaOx1OokA7ZbkeXsjP8b9tXBdWcKt5P+RQcKDu1hug +5WQ== X-Gm-Message-State: AHPjjUiiGhkYw69J85RA7tgF/eggr1ggk/CmUku/ZMHPAqzkiPfYNQID qQgZK3bDOPNuEYQ1yI1TQfZL/g== X-Google-Smtp-Source: AOwi7QAS7O4I/BPDHUDiHC+t8CWTXY2AoTEKbLa9dJDQvOigCOMXn+/veg+vLBuEfB3mIrpexxCK0Q== X-Received: by 10.98.102.82 with SMTP id a79mr3462325pfc.109.1505940368821; Wed, 20 Sep 2017 13:46:08 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , David Windsor , Mike Marshall , linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org, linux-mm@kvack.org, kernel-hardening@lists.openwall.com Date: Wed, 20 Sep 2017 13:45:18 -0700 Message-Id: <1505940337-79069-13-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1505940337-79069-1-git-send-email-keescook@chromium.org> References: <1505940337-79069-1-git-send-email-keescook@chromium.org> Subject: [kernel-hardening] [PATCH v3 12/31] 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 47f3fb9cbec4..ee7b8bfa47c2 100644 --- a/fs/orangefs/super.c +++ b/fs/orangefs/super.c @@ -624,11 +624,16 @@ 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");