From patchwork Sat Mar 30 01:21:07 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tetsuo Handa X-Patchwork-Id: 1070399 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=I-love.SAKURA.ne.jp Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44WLRL6rPpz9sNt for ; Sat, 30 Mar 2019 12:21:34 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730402AbfC3BVL (ORCPT ); Fri, 29 Mar 2019 21:21:11 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:26639 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730343AbfC3BVK (ORCPT ); Fri, 29 Mar 2019 21:21:10 -0400 Received: from fsav401.sakura.ne.jp (fsav401.sakura.ne.jp [133.242.250.100]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id x2U1L8te076553; Sat, 30 Mar 2019 10:21:08 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav401.sakura.ne.jp (F-Secure/fsigk_smtp/530/fsav401.sakura.ne.jp); Sat, 30 Mar 2019 10:21:08 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/530/fsav401.sakura.ne.jp) Received: from [192.168.1.8] (softbank126072090247.bbtec.net [126.72.90.247]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id x2U1L6qF076537 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NO); Sat, 30 Mar 2019 10:21:08 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Subject: [PATCH] NFS: Forbid setting AF_INET6 to "struct sockaddr_in"->sin_family. To: anna.schumaker@netapp.com, trond.myklebust@hammerspace.com References: <00000000000062ece6057bbd0e4a@google.com> Cc: syzbot , bfields@fieldses.org, davem@davemloft.net, jlayton@kernel.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com From: Tetsuo Handa Message-ID: Date: Sat, 30 Mar 2019 10:21:07 +0900 User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.6.0 MIME-Version: 1.0 In-Reply-To: <00000000000062ece6057bbd0e4a@google.com> Content-Language: en-US Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org syzbot is reporting uninitialized value at rpc_sockaddr2uaddr() [1]. This is because syzbot is setting AF_INET6 to "struct sockaddr_in"->sin_family (which is embedded into user-visible "struct nfs_mount_data" structure) despite nfs23_validate_mount_data() cannot pass sizeof(struct sockaddr_in6) bytes of AF_INET6 address to rpc_sockaddr2uaddr(). Since "struct nfs_mount_data" structure is user-visible, we can't change "struct nfs_mount_data" to use "struct sockaddr_storage". Therefore, assuming that everybody is using AF_INET family when passing address via "struct nfs_mount_data"->addr, reject if its sin_family is not AF_INET. [1] https://syzkaller.appspot.com/bug?id=599993614e7cbbf66bc2656a919ab2a95fb5d75c Reported-by: syzbot Signed-off-by: Tetsuo Handa --- fs/nfs/super.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/nfs/super.c b/fs/nfs/super.c index 23790c7..c27ac96 100644 --- a/fs/nfs/super.c +++ b/fs/nfs/super.c @@ -2041,7 +2041,8 @@ static int nfs23_validate_mount_data(void *options, memcpy(sap, &data->addr, sizeof(data->addr)); args->nfs_server.addrlen = sizeof(data->addr); args->nfs_server.port = ntohs(data->addr.sin_port); - if (!nfs_verify_server_address(sap)) + if (sap->sa_family != AF_INET || + !nfs_verify_server_address(sap)) goto out_no_address; if (!(data->flags & NFS_MOUNT_TCP))