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=-8.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 110DDC4363D for ; Fri, 25 Sep 2020 16:38:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B715B2344C for ; Fri, 25 Sep 2020 16:38:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601051902; bh=QGgqzYHKwLhU8qGchhG95ocnro20Uloj/gEjGanOpKI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=hgPHL5PGm+VwXORv2c1rJt7c/gVhur7kkzGSXU/8+fXXe1X3W61gKNCNGgSFOr4V2 6Z0VCzVBvZESqzkcGTiJ+q3YYl17HOf0S4EE2SLUAxKOiSsexQJOdmK4VQnze1uT3E 8mxK5fryjESq9BR4iM10Vwubhi42hYGqCGvR4wd0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729464AbgIYQiV (ORCPT ); Fri, 25 Sep 2020 12:38:21 -0400 Received: from mail.kernel.org ([198.145.29.99]:35548 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728069AbgIYQiV (ORCPT ); Fri, 25 Sep 2020 12:38:21 -0400 Received: from gmail.com (unknown [104.132.1.76]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C4E52206BE; Fri, 25 Sep 2020 16:38:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601051901; bh=QGgqzYHKwLhU8qGchhG95ocnro20Uloj/gEjGanOpKI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=WXZNV2sUi/3rDC09k4sGxhoTano9Jr5dbiDuP626WoskNDGjMd0MRTKAnMKx4XQxz nIHpWb7E/D/qUUuw2r65VKRu9FEMgK2yAyy47ShyMUlLxmwtDf7Si917sgWXqYImby QLuYCTdxfodQirmxcyN15uEStZSRHx5K10lZ3IMk= Date: Fri, 25 Sep 2020 09:38:19 -0700 From: Eric Biggers To: Chao Yu Cc: syzbot , chao@kernel.org, glider@google.com, jaegeuk@kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [f2fs-dev] KMSAN: uninit-value in f2fs_lookup Message-ID: <20200925163819.GA3315208@gmail.com> References: <000000000000f9f80905b01c7185@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 25, 2020 at 05:06:33PM +0800, Chao Yu wrote: > Hi, > > I don't see any problem here, thanks for your report. :) > > Thanks, What about if max_depth == 0 in __f2fs_find_entry()? Then __f2fs_find_entry() would return NULL without initializing *res_page. A fix could be: diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index 069f498af1e3..ceb4431b5669 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -357,16 +357,15 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, unsigned int max_depth; unsigned int level; + *res_page = NULL; + if (f2fs_has_inline_dentry(dir)) { - *res_page = NULL; de = f2fs_find_in_inline_dir(dir, fname, res_page); goto out; } - if (npages == 0) { - *res_page = NULL; + if (npages == 0) goto out; - } max_depth = F2FS_I(dir)->i_current_depth; if (unlikely(max_depth > MAX_DIR_HASH_DEPTH)) { @@ -377,7 +376,6 @@ struct f2fs_dir_entry *__f2fs_find_entry(struct inode *dir, } for (level = 0; level < max_depth; level++) { - *res_page = NULL; de = find_in_level(dir, level, fname, res_page); if (de || IS_ERR(*res_page)) break;