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=-8.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 67AA1C4338F for ; Tue, 10 Aug 2021 13:37:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3CB6960F41 for ; Tue, 10 Aug 2021 13:37:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241558AbhHJNha (ORCPT ); Tue, 10 Aug 2021 09:37:30 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:47886 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237223AbhHJNh1 (ORCPT ); Tue, 10 Aug 2021 09:37:27 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1628602625; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2LDlPss9QRTaBr474xlXhjE3rgK4GGCgbW9ZnFPF4VA=; b=Wnq1QCh5gHGKKekL/hvFPHiVmg3zyicHZrN/pX8y0Fu0LP9I2thhpAL8WoX/dphEqkHKTP ApFPEjjcsnKzknZQAtVuMCOroq69X8sTW5K6tYJFXVA6Mlf7v2AZlZRV4AVY2lJGE17q7g iadaLBQcaS90DNfgxfM8ppG7BL0YVmo= Received: from mail-qv1-f70.google.com (mail-qv1-f70.google.com [209.85.219.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-286-DHu_JRabNtWV-7h44uxBDw-1; Tue, 10 Aug 2021 09:37:04 -0400 X-MC-Unique: DHu_JRabNtWV-7h44uxBDw-1 Received: by mail-qv1-f70.google.com with SMTP id b8-20020a0562141148b02902f1474ce8b7so15383296qvt.20 for ; Tue, 10 Aug 2021 06:37:04 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=2LDlPss9QRTaBr474xlXhjE3rgK4GGCgbW9ZnFPF4VA=; b=Cp+GwRczCkdLhQv0HzMv6x7TWiYXWVU4lhvKZLAmHTLPYomcCOsiAta1WT5frg4eKg bslQQO0C2Cg/lD18ek6VtZLupdeXHSxkxKY8izPOfrd+dyl73JNgTLnq9mHTB8xYTwcd Qz1GsMn/WEn1Rn7Cf6G3maR+UmwDM1kxzTvgkrHmpffKXbsyk/RmuwbjcogLys8T4xPA WUh4cLmuRNdIKoA+E6KsoY8sgQh92/C6nAQHQ0gya/lyzPrDAUBlqBhqLl8B02SBLGfR mgGl1N6H8/MeeUHk2GCSlgUjsJqYuL1KTxFJwoVX7nQK3f28hWoORvVYjYOCVPUX5QJa UTVQ== X-Gm-Message-State: AOAM530AeLBZFss6s5cjhA/INNLTCdFUxHmvqkZC7/ARZgWP8UJUr+uK S5QuqD9nFGlQvxmENH51DnaPQ8MR1Kzn+oULRh9K6AwwpeBGU9ui4To/VQUQPkvmTO76nPB+owX ZKB04ysw4toPieFTja4FQsVFX X-Received: by 2002:ac8:665a:: with SMTP id j26mr8267053qtp.173.1628602623923; Tue, 10 Aug 2021 06:37:03 -0700 (PDT) X-Google-Smtp-Source: ABdhPJweRWFo+H68Fj3T4T7Iatetn7HaR/6adb+j5+Nf6P0/km/pU4GuQrXekeo83c8dya9bo80j0A== X-Received: by 2002:ac8:665a:: with SMTP id j26mr8267031qtp.173.1628602623592; Tue, 10 Aug 2021 06:37:03 -0700 (PDT) Received: from crecklin.bos.csb (c-24-60-53-55.hsd1.nh.comcast.net. [24.60.53.55]) by smtp.gmail.com with ESMTPSA id z12sm7894678qtw.90.2021.08.10.06.37.02 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 10 Aug 2021 06:37:03 -0700 (PDT) Subject: Re: [PATCH] fix UBSAN splat in test_scanf To: Andy Shevchenko Cc: pmladek@suse.com, rostedt@goodmis.org, senozhatsky@chromium.org, linux@rasmusvillemoes.dk, linux-kernel@vger.kernel.org References: <20210809102013.525671-1-crecklin@redhat.com> From: Christoph von Recklinghausen Message-ID: <1f4aa937-8e5d-33db-6479-e9b2011be147@redhat.com> Date: Tue, 10 Aug 2021 09:37:01 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8/10/21 9:31 AM, Andy Shevchenko wrote: > On Mon, Aug 09, 2021 at 06:20:13AM -0400, Chris von Recklinghausen wrote: > > Thanks for the report and fix! > > First of all, have you seen this: > https://lore.kernel.org/lkml/20210727150132.28920-1-andriy.shevchenko@linux.intel.com/T/#u > ? No I hadn't seen it. I'll defer to this fix then. Thanks, Chris > >> On a system with CONFIG_UBSAN_SHIFT=y, the following splat was observed: >> [ 104.676826] test_scanf: loaded. >> [ 104.680862] ================================================================================ >> [ 104.690304] UBSAN: shift-out-of-bounds in lib/test_scanf.c:274:51 >> [ 104.697144] shift exponent 32 is too large for 32-bit type 'unsigned int' > As you may see in the above the rule of thumb is to include only meaningful > parts of the oops. >