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=-12.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 88BC6C433DB for ; Thu, 18 Feb 2021 00:48:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3525961493 for ; Thu, 18 Feb 2021 00:48:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230148AbhBRAsS (ORCPT ); Wed, 17 Feb 2021 19:48:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39958 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230021AbhBRAsR (ORCPT ); Wed, 17 Feb 2021 19:48:17 -0500 Received: from mail-pf1-x42d.google.com (mail-pf1-x42d.google.com [IPv6:2607:f8b0:4864:20::42d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AD901C061574; Wed, 17 Feb 2021 16:47:37 -0800 (PST) Received: by mail-pf1-x42d.google.com with SMTP id u143so121643pfc.7; Wed, 17 Feb 2021 16:47:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=9AQCchQC3RVaMv/Hcn0M+7TZdZEVJRof4WAPBKGbACg=; b=lmEGx+TeyVIR9oSiK4robQdT8vT9B9D2gCCx1AKSquREKfdRrdvFjot6+1PwmkMySC JGcfgQ3tzcMUP0a79XDAa8BoX9lJSTX6darSNC0HVNzhQ8ZsmcdYVVmajvpbheZqXufq 3LSlRjO4tRJJO8bO8PrN+Doduh6OH4ZotEhk55FQ9t0HEwmitwRg8S/x7JCAVZ4RaW4V uIBIRA5zeiwI0OKpUJzS/s3FGmROLTLujN/SGTDO1Cuxf52CufpFnu3WEmOqiihYDwPr /MONKVCvl+9TJxdgsSQeUPv5Tub82a0tNMPp48eut8pQCD6oOVnljXOVLe/mi0ntkUMV Ae4A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=9AQCchQC3RVaMv/Hcn0M+7TZdZEVJRof4WAPBKGbACg=; b=GNJ77woeBY7yoXJ2ZUdfZXD2v60ly3wkf0WYF3b5EQDigQEXFMqjsNT+vVzIT4Rw2Q WhJgGwakJqeAJMPWd+eCrZyxF3QOjhJ3RkPwe4hMAQ343P+gET857TRKBtB1AIM+EMs6 ETil8SR9eHfvDnxzqV/eSfVsgDbrAZ3vMsMAmpR9Ps0D9MRx8r0SQtCDa4dAlejlmppX p0oiSvdU0SIyJ/92CepWietOAuq9lFtczJQq0PQEIMHekZtKZJgzQNBLAtmbuKltTRHK dnnPMJQrCehLVYty3DwI+isa5Ke6fOhuHcqxUem3d/IjcdPhsvYG3VoJCoRviakJiSAt 2djw== X-Gm-Message-State: AOAM531auC+pRZA/lA6uScREct6joacC7THi1HyHPZrZDiZgypkWVwBx vLEFndUo4KPZH+omeflYZn0= X-Google-Smtp-Source: ABdhPJyFVk8+ypuV2LLDlViNh2a+mh0HOrRUj0ErpARIXvmeJjPbciPtcJaO663PjuaXM5qhAJ9oUg== X-Received: by 2002:a05:6a00:2353:b029:1ba:d824:f1dc with SMTP id j19-20020a056a002353b02901bad824f1dcmr1846175pfj.9.1613609257138; Wed, 17 Feb 2021 16:47:37 -0800 (PST) Received: from localhost ([2409:10:2e40:5100:6e29:95ff:fe2d:8f34]) by smtp.gmail.com with ESMTPSA id q139sm3368597pfc.2.2021.02.17.16.47.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Feb 2021 16:47:36 -0800 (PST) Date: Thu, 18 Feb 2021 09:47:34 +0900 From: Sergey Senozhatsky To: "Enrico Weigelt, metux IT consult" Cc: linux-kernel@vger.kernel.org, pmladek@suse.com, rostedt@goodmis.org, sergey.senozhatsky@gmail.com, andriy.shevchenko@linux.intel.com, linux@rasmusvillemoes.dk, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [PATCH] lib: vsprintf: check for NULL device_node name in device_node_string() Message-ID: References: <20210217121543.13010-1-info@metux.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210217121543.13010-1-info@metux.net> Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On (21/02/17 13:15), Enrico Weigelt, metux IT consult wrote: > Under rare circumstances it may happen that a device node's name is NULL > (most likely kernel bug in some other place). In such situations anything > but helpful, if the debug printout crashes, and nobody knows what actually > happened here. > > Therefore protect it by an explicit NULL check and print out an extra > warning. > > Signed-off-by: Enrico Weigelt, metux IT consult > --- > lib/vsprintf.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/lib/vsprintf.c b/lib/vsprintf.c > index 3b53c73580c5..050a60b88073 100644 > --- a/lib/vsprintf.c > +++ b/lib/vsprintf.c > @@ -2013,6 +2013,10 @@ char *device_node_string(char *buf, char *end, struct device_node *dn, > break; > case 'n': /* name */ > p = fwnode_get_name(of_fwnode_handle(dn)); > + if (!p) { > + pr_warn("device_node without name. Kernel bug ?\n"); > + p = ""; > + } > precision = str_spec.precision; > str_spec.precision = strchrnul(p, '@') - p; > buf = string(buf, end, p, str_spec); What about other fwnode_get_name() calls in vsprintf? -ss