From patchwork Mon Sep 19 11:05:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tetsuo Handa X-Patchwork-Id: 12980256 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ACC54C6FA82 for ; Mon, 19 Sep 2022 11:06:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229936AbiISLGG (ORCPT ); Mon, 19 Sep 2022 07:06:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42598 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229722AbiISLGF (ORCPT ); Mon, 19 Sep 2022 07:06:05 -0400 Received: from www262.sakura.ne.jp (www262.sakura.ne.jp [202.181.97.72]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 03BA0B84C; Mon, 19 Sep 2022 04:06:02 -0700 (PDT) Received: from fsav415.sakura.ne.jp (fsav415.sakura.ne.jp [133.242.250.114]) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTP id 28JB5EAU024945; Mon, 19 Sep 2022 20:05:14 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Received: from www262.sakura.ne.jp (202.181.97.72) by fsav415.sakura.ne.jp (F-Secure/fsigk_smtp/550/fsav415.sakura.ne.jp); Mon, 19 Sep 2022 20:05:14 +0900 (JST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/fsav415.sakura.ne.jp) Received: from [192.168.1.9] (M106072142033.v4.enabler.ne.jp [106.72.142.33]) (authenticated bits=0) by www262.sakura.ne.jp (8.15.2/8.15.2) with ESMTPSA id 28JB5ET3024941 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NO); Mon, 19 Sep 2022 20:05:14 +0900 (JST) (envelope-from penguin-kernel@I-love.SAKURA.ne.jp) Message-ID: <3411f396-a41e-76cb-7836-941fbade81dc@I-love.SAKURA.ne.jp> Date: Mon, 19 Sep 2022 20:05:12 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.2.2 Subject: [PATCH (urgent)] vfs: fix uninitialized uid/gid in chown_common() Content-Language: en-US To: linux-fsdevel , Christian Brauner , Alexander Viro References: <00000000000008058305e9033f85@google.com> Cc: linux-security-module@vger.kernel.org, syzbot , syzkaller-bugs@googlegroups.com From: Tetsuo Handa In-Reply-To: <00000000000008058305e9033f85@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org syzbot is reporting uninit-value in tomoyo_path_chown() [1], for chown_common() is by error passing uninitialized newattrs.ia_vfsuid to security_path_chown() via from_vfsuid() when user == -1 is passed. We must initialize newattrs.ia_vfs{u,g}id fields in order to make from_vfs{u,g}id() work. Link: https://syzkaller.appspot.com/bug?extid=541e21dcc32c4046cba9 [1] Reported-by: syzbot Signed-off-by: Tetsuo Handa --- fs/open.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/open.c b/fs/open.c index 8a813fa5ca56..0550efb7b53a 100644 --- a/fs/open.c +++ b/fs/open.c @@ -709,6 +709,8 @@ int chown_common(const struct path *path, uid_t user, gid_t group) kuid_t uid; kgid_t gid; + newattrs.ia_vfsuid = VFSUIDT_INIT(KUIDT_INIT(-1)); + newattrs.ia_vfsgid = VFSGIDT_INIT(KGIDT_INIT(-1)); uid = make_kuid(current_user_ns(), user); gid = make_kgid(current_user_ns(), group);