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 60D92C433F5 for ; Wed, 2 Mar 2022 01:34:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236152AbiCBBey (ORCPT ); Tue, 1 Mar 2022 20:34:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39872 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234218AbiCBBew (ORCPT ); Tue, 1 Mar 2022 20:34:52 -0500 Received: from mail-pl1-x643.google.com (mail-pl1-x643.google.com [IPv6:2607:f8b0:4864:20::643]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BDCCB5748B for ; Tue, 1 Mar 2022 17:34:10 -0800 (PST) Received: by mail-pl1-x643.google.com with SMTP id q11so237670pln.11 for ; Tue, 01 Mar 2022 17:34:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :cc:references:from:in-reply-to:content-transfer-encoding; bh=WvbfaPTFctx/ZBq/LbbOp5Y1TVJ+xSqnWCCTA+Z/BLo=; b=hVDRrGDlFebSSqMoxkVgXMfbIhKd7vB31icR6jp+FDN9jEoc3/f+hhT+TfYm+yQ113 Jao9U9WNhS+eUSrPnCAgyIh2K/n4cE3RCee/HhVr1YAZqW7v4wI9fQO09xsp5BKqAD2x VsIh7Jhw6uh0B6Zv8uP635f7wJ4TgE+HGZZaGtuZLe+FWzbQPEBSVdhTgSyaCpR65IJ8 lM7+mmgMkj1OBNAHJXFgAkl1MtpMJnCX4V0v+lfSCoNKvVPpjfWPkEEj6hO0BbYzn6r8 In/Ck5es2mK8aZ5AAiOammC+fCQmE346I+zs/Xj406NX2ds9JyBk+vSgx8RvC4bhqesG SryQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=WvbfaPTFctx/ZBq/LbbOp5Y1TVJ+xSqnWCCTA+Z/BLo=; b=EkD5BNUtSu8R+iC19iWW2B7x0+gJVAeYJXAObj0gYDSj8gpVis0208bdH7aIKsluaH lT9xU8VIMI2npOtMnglRwocL/Lvm/tVP8HTwNcZMvDg2TwUAnOdN95zd5MxGE9RVzzpw 5fXGP0cpAHYIKq0PRScK8Gvn2j2inUgoWdITnOwPcsab3d4Xz1SxZyLImvYlpxv9rea5 3rMc9tezcMvwcYQDU+y36AXZN2rkZDF3GEwpRI1XjbmYahVd19Rzf4ioaQrbmxCTMuvB m4OU0lE5y3XOFTcJm3Q7pXGkdcxXmOyUK9pXoivS85yYCuoWdXltPvyRCGRut4b+NZV4 RcDw== X-Gm-Message-State: AOAM531numlevJvUX6m5cr3mVbVsrKbtcln5LL2GPstHbET2/9I2Q9uX DoHF47tiP7dwuBjujEnqukI= X-Google-Smtp-Source: ABdhPJz6zxh10Pr83NPul6JjmZR+Q9CQqGzwlbLF8IduW22KXvc3PsJaORPgaxeL5JcmWfaefjyRfg== X-Received: by 2002:a17:90b:10b:b0:1bc:6f86:b209 with SMTP id p11-20020a17090b010b00b001bc6f86b209mr24660317pjz.33.1646184850280; Tue, 01 Mar 2022 17:34:10 -0800 (PST) Received: from [10.11.37.162] ([103.84.139.54]) by smtp.gmail.com with ESMTPSA id b187-20020a621bc4000000b004f3c8f3b560sm16963844pfb.129.2022.03.01.17.34.07 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 01 Mar 2022 17:34:09 -0800 (PST) Message-ID: <43e1dba5-2af7-658b-ae45-c7a6c1c0dc6d@gmail.com> Date: Wed, 2 Mar 2022 09:34:02 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH] powerpc: kernel: fix a refcount leak in format_show() Content-Language: en-US To: Tyrel Datwyler , Michael Ellerman , benh@kernel.crashing.org, paulus@samba.org Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org References: <20220228091103.39749-1-hbh25y@gmail.com> <87o82pomrc.fsf@mpe.ellerman.id.au> <825f5cba-a62b-a691-225e-22f6bb9b10a8@linux.ibm.com> From: Hangyu Hua In-Reply-To: <825f5cba-a62b-a691-225e-22f6bb9b10a8@linux.ibm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Thanks. I will resubmit my patch latter. On 2022/3/2 03:50, Tyrel Datwyler wrote: > On 3/1/22 04:55, Michael Ellerman wrote: >> Hangyu Hua writes: >>> node needs to be dropped when of_property_read_string fails. So an earlier call >>> to of_node_put is required here. >> >> That's true but ... >> >>> diff --git a/arch/powerpc/kernel/secvar-sysfs.c b/arch/powerpc/kernel/secvar-sysfs.c >>> index a0a78aba2083..cd0fa7028d86 100644 >>> --- a/arch/powerpc/kernel/secvar-sysfs.c >>> +++ b/arch/powerpc/kernel/secvar-sysfs.c >>> @@ -30,13 +30,12 @@ static ssize_t format_show(struct kobject *kobj, struct kobj_attribute *attr, >>> return -ENODEV; >> >> There's also a reference leak there ^ >> >> So if you're going to touch this code I'd like you to fix both reference >> leaks in a single patch please. >> >> Having the error cases set rc and then goto "out" which does the >> of_node_put() is the obvious solution I think. > > update_kobj_size() in the same source file provides a good example of the > suggested solution. > > -Tyrel > >> >> cheers >> >>> rc = of_property_read_string(node, "format", &format); >>> + of_node_put(node); >>> if (rc) >>> return rc; >>> >>> rc = sprintf(buf, "%s\n", format); >>> >>> - of_node_put(node); >>> - >>> return rc; >>> } >>> >>> -- >>> 2.25.1 >