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,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 E2879C2D0A3 for ; Thu, 12 Nov 2020 11:18:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 67AA32220B for ; Thu, 12 Nov 2020 11:18:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=cirrus.com header.i=@cirrus.com header.b="aODBeVhf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727805AbgKLLSh (ORCPT ); Thu, 12 Nov 2020 06:18:37 -0500 Received: from mx0a-001ae601.pphosted.com ([67.231.149.25]:3464 "EHLO mx0b-001ae601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727147AbgKLLSg (ORCPT ); Thu, 12 Nov 2020 06:18:36 -0500 Received: from pps.filterd (m0077473.ppops.net [127.0.0.1]) by mx0a-001ae601.pphosted.com (8.16.0.43/8.16.0.43) with SMTP id 0ACB6r11012339; Thu, 12 Nov 2020 05:18:05 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cirrus.com; h=from : to : cc : subject : date : message-id : mime-version : content-transfer-encoding : content-type; s=PODMain02222019; bh=0JXW40qNmOIXAMSKQ/j6loVZ/s0nO8nx+m2h3QbPDUw=; b=aODBeVhfvqpSrCBbB8JiVzT3eaXCn8nLOM5KC6fIRIN6FtwQ4cnZLAyIj9+ME4S5yrBl YnDYC+4C4NQJ2BEDQXJg1tDLil4gC12PTvQly0utrtqZL9ISTHoa32M9zNlz7ICuU+bD o9ijTQONQGGMb99wzAi9wJQRJbZV2ZKIvX6JjThEEa4SuV+QfnSh6l4UQ9AhANbJCMy5 6MiwUj52pRiW2/vjgTlRmsj37S02mtXKvT3iGdJ14S1azXf8RhP+T0SGcZFUVY9h/r2i lV2YKuD2oVFnbjkE0BnTZaVvt4phar4bKcUCkNr4y+G1ubGVY0FofgEKjCzD7kzSgRwM zQ== Received: from ediex01.ad.cirrus.com ([5.172.152.52]) by mx0a-001ae601.pphosted.com with ESMTP id 34rn2yh4u6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Thu, 12 Nov 2020 05:18:04 -0600 Received: from EDIEX01.ad.cirrus.com (198.61.84.80) by EDIEX01.ad.cirrus.com (198.61.84.80) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1913.5; Thu, 12 Nov 2020 11:18:02 +0000 Received: from ediswmail.ad.cirrus.com (198.61.86.93) by EDIEX01.ad.cirrus.com (198.61.84.80) with Microsoft SMTP Server id 15.1.1913.5 via Frontend Transport; Thu, 12 Nov 2020 11:18:02 +0000 Received: from AUSNPC0LSNW1-debian.cirrus.com (ausnpc0lsnw1.ad.cirrus.com [198.61.64.168]) by ediswmail.ad.cirrus.com (Postfix) with ESMTP id EAA9845; Thu, 12 Nov 2020 11:18:01 +0000 (UTC) From: Richard Fitzgerald To: , , CC: , , Richard Fitzgerald Subject: [PATCH] lib: vsprintf: Avoid 32-bit truncation in vsscanf number parsing Date: Thu, 12 Nov 2020 11:17:59 +0000 Message-ID: <20201112111759.16377-1-rf@opensource.cirrus.com> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 lowpriorityscore=0 spamscore=0 mlxscore=0 priorityscore=1501 bulkscore=0 impostorscore=0 phishscore=0 malwarescore=0 clxscore=1011 adultscore=0 mlxlogscore=999 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011120067 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Number conversion in vsscanf converts a whole string of digits and then extracts the field width part from the converted value. The maximum run of digits is limited by overflow. Conversion was using either simple_strto[u]l or simple_strto[u]ll based on the 'L' qualifier. This created a difference in truncation between builds where long is 32-bit and builds where it is 64-bit. This especially affects parsing a run of contiguous digits into separate fields - the maximum length of the run is 16 digits if long is 64-bit but only 8 digits if long is 32-bits. For example a conversion "%6x%6x" would convert both fields correctly if long is 64-bit but not if long is 32-bit. It is undesirable for vsscanf to parse numbers differently depending on the size of long on the target build. As simple_strto[u]l just calls simple_strto[u]ll anyway the conversion is always 64-bit, and the result is manipulated as a u64, so this is an avoidable behaviour difference between 32-bit and 64-bit builds. The conversion can call simple_strto[u]ll directly and preserve the full 64-bits that were parsed out of the string. Signed-off-by: Richard Fitzgerald --- lib/vsprintf.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) diff --git a/lib/vsprintf.c b/lib/vsprintf.c index 14c9a6af1b23..63b6cddfa7f7 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -3444,13 +3444,9 @@ int vsscanf(const char *buf, const char *fmt, va_list args) break; if (is_sign) - val.s = qualifier != 'L' ? - simple_strtol(str, &next, base) : - simple_strtoll(str, &next, base); + val.s = simple_strtoll(str, &next, base); else - val.u = qualifier != 'L' ? - simple_strtoul(str, &next, base) : - simple_strtoull(str, &next, base); + val.u = simple_strtoull(str, &next, base); if (field_width > 0 && next - str > field_width) { if (base == 0) -- 2.20.1