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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,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 20388C433ED for ; Fri, 21 May 2021 04:39:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E90F86138C for ; Fri, 21 May 2021 04:39:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239169AbhEUElI (ORCPT ); Fri, 21 May 2021 00:41:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:49836 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239163AbhEUElH (ORCPT ); Fri, 21 May 2021 00:41:07 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 79DC161261; Fri, 21 May 2021 04:39:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621571984; bh=LIXtOlzou89RhBkeHHOcUBK4LV9zHewt22Q/WA5LUm4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uDh77wLLV88u+gdWd0xTEl0KdZloBBLcCu7NyCgMPOy7OnFlWfUTZPNXP+O/pBuyA 4ziBo/uB76Elsn0QfYpExrXr5m90e5TnUvzSIB9XLwVuN3kClSDEN5PSuO0e0nnMRR SXHj/+QnDiIkH0gsx3gyMDaay0nJIbmPN2nhE+CU= Date: Fri, 21 May 2021 06:39:40 +0200 From: Greg KH To: Austin Kim Cc: tj@kernel.org, neilb@suse.de, linux-kernel@vger.kernel.org, austin.kim@lge.com Subject: Re: [PATCH] kernfs: move return value check after kmalloc() Message-ID: References: <20210521025525.GA1379@raspberrypi> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210521025525.GA1379@raspberrypi> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 21, 2021 at 03:55:25AM +0100, Austin Kim wrote: > With 414985ae23c0 ("sysfs, kernfs: move file core code to fs/kernfs/file.c"), > 'return -ENOMEM' is executed when kmalloc() returns NULL. > > Since 'commit 4ef67a8c95f3 ("sysfs/kernfs: make read requests on pre-alloc > files use the buffer.")', 'return -ENOMEM' statement is not properly located. > > Fix it by moving 'return -ENOMEM' after return from kmalloc(). > > Fixes: 4ef67a8c95f3 ("sysfs/kernfs: make read requests on pre-alloc files use the buffer.") > Signed-off-by: Austin Kim > --- > fs/kernfs/file.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c > index c75719312147..c5e2429af836 100644 > --- a/fs/kernfs/file.c > +++ b/fs/kernfs/file.c > @@ -191,10 +191,11 @@ static ssize_t kernfs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) > buf = of->prealloc_buf; > if (buf) > mutex_lock(&of->prealloc_mutex); > - else > + else { > buf = kmalloc(len, GFP_KERNEL); > - if (!buf) > - return -ENOMEM; > + if (!buf) > + return -ENOMEM; > + } > > /* > * @of->mutex nests outside active ref and is used both to ensure that > -- > 2.20.1 > Like Neil said, I don't see the "bug" you are fixing here. What is currently wrong with the existing code? thanks, greg k-h