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 5FA5FC433FE for ; Wed, 30 Mar 2022 02:57:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242167AbiC3C7H convert rfc822-to-8bit (ORCPT ); Tue, 29 Mar 2022 22:59:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60862 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241180AbiC3C7H (ORCPT ); Tue, 29 Mar 2022 22:59:07 -0400 Received: from eu-smtp-delivery-151.mimecast.com (eu-smtp-delivery-151.mimecast.com [185.58.85.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6300C637D for ; Tue, 29 Mar 2022 19:57:20 -0700 (PDT) Received: from AcuMS.aculab.com (156.67.243.121 [156.67.243.121]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id uk-mta-260-sKBCBKFINtqPnd_8YrB5ZA-1; Wed, 30 Mar 2022 03:57:17 +0100 X-MC-Unique: sKBCBKFINtqPnd_8YrB5ZA-1 Received: from AcuMS.Aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) by AcuMS.aculab.com (fd9f:af1c:a25b:0:994c:f5c2:35d6:9b65) with Microsoft SMTP Server (TLS) id 15.0.1497.32; Wed, 30 Mar 2022 03:57:16 +0100 Received: from AcuMS.Aculab.com ([fe80::994c:f5c2:35d6:9b65]) by AcuMS.aculab.com ([fe80::994c:f5c2:35d6:9b65%12]) with mapi id 15.00.1497.033; Wed, 30 Mar 2022 03:57:15 +0100 From: David Laight To: 'Michael Walle' , Xu Yilun , Tom Rix , Jean Delvare , Guenter Roeck , Andrew Lunn , Heiner Kallweit , Russell King , "David S . Miller" , Jakub Kicinski , Paolo Abeni CC: "linux-hwmon@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "netdev@vger.kernel.org" Subject: RE: [PATCH v2 1/5] hwmon: introduce hwmon_sanitize_name() Thread-Topic: [PATCH v2 1/5] hwmon: introduce hwmon_sanitize_name() Thread-Index: AQHYQ4dUrIB0cQMH/kajVzJ0H3I8wazXOSsg Date: Wed, 30 Mar 2022 02:57:15 +0000 Message-ID: <16d8b45eba7b44e78fa8205e6666f2bd@AcuMS.aculab.com> References: <20220329160730.3265481-1-michael@walle.cc> <20220329160730.3265481-2-michael@walle.cc> In-Reply-To: <20220329160730.3265481-2-michael@walle.cc> Accept-Language: en-GB, en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.202.205.107] MIME-Version: 1.0 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=C51A453 smtp.mailfrom=david.laight@aculab.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: aculab.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org From: Michael Walle > Sent: 29 March 2022 17:07 > > More and more drivers will check for bad characters in the hwmon name > and all are using the same code snippet. Consolidate that code by adding > a new hwmon_sanitize_name() function. I'm assuming these 'bad' hwmon names come from userspace? Like ethernet interface names?? Is silently changing the name of the hwmon entries the right thing to do at all? What happens if the user tries to create both "foo_bar" and "foo-bar"? I'm sure that is going to go horribly wrong somewhere. It would certainly make sense to have a function to verify the name is actually valid. Then bad names can be rejected earlier on. I'm also intrigued about the list of invalid characters: +static bool hwmon_is_bad_char(const char ch) +{ + switch (ch) { + case '-': + case '*': + case ' ': + case '\t': + case '\n': + return true; + default: + return false; + } +} If '\t' and '\n' are invalid why are all the other control characters allowed? I'm guessing '*' is disallowed because it is the shell wildcard? So what about '?'. Then I'd expect '/' to be invalid - but that isn't checked. Never mind all the values 0x80 to 0xff - they are probably worse than whitespace. OTOH why are any characters invalid at all - except '/'? David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)