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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 6D9DEC2BA15 for ; Sat, 4 Apr 2020 15:50:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2FF3B206E6 for ; Sat, 4 Apr 2020 15:50:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586015448; bh=0Nn+EFUzUjFBB+9yzouXCkUYoa5BAhVneCkFnDND6d4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=U21gqlup7RFkMepKi0kZFSvaEgYoQ0+dScNDFSYzbGnFjH7XLXGTHpGZkBWJZ7sRc P0Yr57khzKlrnjILC8j8sVbBmaRKJQQUKC7W6e56Tc2oILpa+ZxJFd1CbqHPt1Zmaz Nl37K3PDcHa+ZsjqxJlr1ryKjl9hSfDKHIbron2M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726353AbgDDPur (ORCPT ); Sat, 4 Apr 2020 11:50:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:42380 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726130AbgDDPuq (ORCPT ); Sat, 4 Apr 2020 11:50:46 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 36704206E6; Sat, 4 Apr 2020 15:50:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586015445; bh=0Nn+EFUzUjFBB+9yzouXCkUYoa5BAhVneCkFnDND6d4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qJ2Npy7plxKmyeQJZrczC3n26CVBnACKU6IgjVyrjMQ1IyiyGSLHX4Wvw0u56uA91 k0vX8QHI1fzvN6NQBb2jxEmq+8UTfS9N8ZO+Ouecx69XxZ690RY+XApmQIR4JZ9pOd SdLiVERAxzZbwO/61tuXlG56flA5KGrBJurbt6hY= Date: Sat, 4 Apr 2020 17:50:40 +0200 From: Greg KH To: Taehee Yoo Cc: davem@davemloft.net, kuba@kernel.org, rafael@kernel.org, j.vosburgh@gmail.com, vfalico@gmail.com, andy@greyhouse.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, mitch.a.williams@intel.com Subject: Re: [PATCH net v2 1/3] class: add class_has_file_ns() helper function Message-ID: <20200404155040.GC1476305@kroah.com> References: <20200404141827.26255-1-ap420073@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200404141827.26255-1-ap420073@gmail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Apr 04, 2020 at 02:18:27PM +0000, Taehee Yoo wrote: > The new helper function is to check whether the class file is existing > or not. This function will be used by networking stack to > check "/sys/class/net/*" file. > > Reported-by: syzbot+830c6dbfc71edc4f0b8f@syzkaller.appspotmail.com > Fixes: b76cdba9cdb2 ("[PATCH] bonding: add sysfs functionality to bonding (large)") > Signed-off-by: Taehee Yoo > --- > > v1 -> v2: > - Implement class_has_file_ns() instead of class_find_and_get_file_ns(). > - Change headline. > - Add kernel documentation comment. > > drivers/base/class.c | 22 ++++++++++++++++++++++ > include/linux/device/class.h | 3 ++- > 2 files changed, 24 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/class.c b/drivers/base/class.c > index bcd410e6d70a..a2f2787f6aa7 100644 > --- a/drivers/base/class.c > +++ b/drivers/base/class.c > @@ -105,6 +105,28 @@ void class_remove_file_ns(struct class *cls, const struct class_attribute *attr, > sysfs_remove_file_ns(&cls->p->subsys.kobj, &attr->attr, ns); > } > > +/** > + * class_has_file_ns - check whether file is existing or not > + * @cls: the compatibility class > + * @name: name to look for > + * @ns: the namespace tag to use > + */ > +bool class_has_file_ns(struct class *cls, const char *name, > + const void *ns) Why would you use this? And what happens if the file shows up, or goes away, instantly after this call is made? This feels very broken. greg k-h