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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 034B8C43334 for ; Mon, 27 Jun 2022 14:06:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236677AbiF0OGT (ORCPT ); Mon, 27 Jun 2022 10:06:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44952 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236645AbiF0OGR (ORCPT ); Mon, 27 Jun 2022 10:06:17 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 102F012751 for ; Mon, 27 Jun 2022 07:06:15 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9831D60C0A for ; Mon, 27 Jun 2022 14:06:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF8CAC3411D; Mon, 27 Jun 2022 14:06:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1656338774; bh=fWEojwnmuhByQR8ln3ETFFbd1Xw1B+EJieplMRTu8zo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CWQ+W8GBo4tBpKo2Iy6letizLiAHNCg2rn2SHULXfxIHRYqlt3Ov+YNDho5gLm4Xa o7jXNNbmlDceoKj5ge8YIRwSlVB04Q90vABsU7F6Jx+A2UXJD9Ld2Yqq6+30E+ZUuW zUcIdbh8CtBQ0aE9Q25ZzvqmHCDapIvknxX1d4kc= Date: Mon, 27 Jun 2022 16:06:11 +0200 From: Greg KH To: Zhi Song Cc: vilhelm.gray@gmail.com, rafael@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] isa: put_device after failing to device_register Message-ID: References: <20220615151558.1766067-1-zhi.song@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220615151558.1766067-1-zhi.song@bytedance.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 15, 2022 at 11:15:58PM +0800, Zhi Song wrote: > device_register() is used to register a device with the system. > We need to call put_device() to give up the reference initialized > in device_register() when it returns an error and this will clean > up correctly. > > Fixes: a5117ba7da37 ("Driver model: add ISA bus") > Signed-off-by: Zhi Song > --- > V1 -> V2: Fix up the changelog text correct. > V2 -> V3: Add a fixes tag line specifying the commit where this bug was > introduced. > --- > drivers/base/isa.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/isa.c b/drivers/base/isa.c > index 55e3ee2da98f..cf88f3d77b7d 100644 > --- a/drivers/base/isa.c > +++ b/drivers/base/isa.c > @@ -173,8 +173,10 @@ static int __init isa_bus_init(void) > error = bus_register(&isa_bus_type); > if (!error) { > error = device_register(&isa_bus); > - if (error) > + if (error) { > + put_device(&isa_bus); Did you test this change and notice the kernel log error that happens when you run it? If you can really reproduce this in a real-life situation, you need to do more than just this change. thanks, greg k-h