From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D17B4C43381 for ; Mon, 1 Apr 2019 14:19:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9969D2082C for ; Mon, 1 Apr 2019 14:19:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727346AbfDAOTs (ORCPT ); Mon, 1 Apr 2019 10:19:48 -0400 Received: from www262.sakura.ne.jp ([202.181.97.72]:45192 "EHLO www262.sakura.ne.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726841AbfDAOTs (ORCPT ); Mon, 1 Apr 2019 10:19:48 -0400 Received: from fsav403.sakura.ne.jp (fsav403.sakura.ne.jp [133.242.250.102]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id x31EJbW2052098; Mon, 1 Apr 2019 23:19:38 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav403.sakura.ne.jp (F-Secure/fsigk_smtp/530/fsav403.sakura.ne.jp); Mon, 01 Apr 2019 23:19:37 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/530/fsav403.sakura.ne.jp) Received: from ccsecurity.localdomain (softbank126072090247.bbtec.net [126.72.90.247]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id x31EJVPo052036 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 1 Apr 2019 23:19:37 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) From: Tetsuo Handa To: "David S. Miller" Cc: netdev@vger.kernel.org, Tetsuo Handa , syzbot , syzbot Subject: [PATCH] net: socket: Always initialize family field at move_addr_to_kernel(). Date: Mon, 1 Apr 2019 23:19:22 +0900 Message-Id: <1554128362-12274-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> X-Mailer: git-send-email 1.8.3.1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org syzbot is reporting uninitialized value at rds_connect [1] and rds_bind [2]. This is because syzbot is passing ulen == 0 whereas these functions expects that it is safe to access sockaddr->family field in order to determine minimal ulen size for validation. I noticed that the same problem also exists in tomoyo_check_inet_address() function. Although the right fix might be to scatter around if (ulen < sizeof(__kernel_sa_family_t)) return 0; if the function wants to become no-op when the address is too short or if (ulen < sizeof(__kernel_sa_family_t)) return -EINVAL; if the function wants to reject when the address is too short, we can avoid duplication (at e.g. LSM layer and protocol layer) if we make sure that sockaddr->family field is always accessible. [1] https://syzkaller.appspot.com/bug?id=f4e61c010416c1e6f0fa3ffe247561b60a50ad71 [2] https://syzkaller.appspot.com/bug?id=a4bf9e41b7e055c3823fdcd83e8c58ca7270e38f Reported-by: syzbot Reported-by: syzbot Signed-off-by: Tetsuo Handa --- net/socket.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/socket.c b/net/socket.c index 8255f5b..10a780b 100644 --- a/net/socket.c +++ b/net/socket.c @@ -181,6 +181,7 @@ static ssize_t sock_splice_read(struct file *file, loff_t *ppos, int move_addr_to_kernel(void __user *uaddr, int ulen, struct sockaddr_storage *kaddr) { + kaddr->ss_family = 0; if (ulen < 0 || ulen > sizeof(struct sockaddr_storage)) return -EINVAL; if (ulen == 0) -- 1.8.3.1