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 32025C4167B for ; Wed, 28 Dec 2022 16:43:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234977AbiL1Qn5 (ORCPT ); Wed, 28 Dec 2022 11:43:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36452 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234979AbiL1Qn2 (ORCPT ); Wed, 28 Dec 2022 11:43:28 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 696ECEE19 for ; Wed, 28 Dec 2022 08:37:51 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 15D2BB8171E for ; Wed, 28 Dec 2022 16:37:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 75962C433D2; Wed, 28 Dec 2022 16:37:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672245468; bh=SUJBw4+DYl7yZy510RN/erYq4QOUqjRd4IEOBFkRAfE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Tze70jmO4G4ODsHorvZ4t1I0A+qfyhiHYwKpdURZrqqNEIBoQULLeuzs67i5JmSvI kFqzsYxJEtO9YwybkdrUjG2Zfh+AQ3OtaqHHiX7AQTxDMd9LLTlsCi7bKJI9oYAlRc Nt1wh5J18RqDxIsUiwyUQU2ERbGw1DerSzfqfXb8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zheng Yejian , Hanjun Guo , Randy Dunlap , Vlastimil Babka , Zhang Jinhao , Andrew Morton , Sasha Levin Subject: [PATCH 6.0 0901/1073] acct: fix potential integer overflow in encode_comp_t() Date: Wed, 28 Dec 2022 15:41:29 +0100 Message-Id: <20221228144352.503504102@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144328.162723588@linuxfoundation.org> References: <20221228144328.162723588@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Zheng Yejian [ Upstream commit c5f31c655bcc01b6da53b836ac951c1556245305 ] The integer overflow is descripted with following codes: > 317 static comp_t encode_comp_t(u64 value) > 318 { > 319 int exp, rnd; ...... > 341 exp <<= MANTSIZE; > 342 exp += value; > 343 return exp; > 344 } Currently comp_t is defined as type of '__u16', but the variable 'exp' is type of 'int', so overflow would happen when variable 'exp' in line 343 is greater than 65535. Link: https://lkml.kernel.org/r/20210515140631.369106-3-zhengyejian1@huawei.com Signed-off-by: Zheng Yejian Cc: Hanjun Guo Cc: Randy Dunlap Cc: Vlastimil Babka Cc: Zhang Jinhao Signed-off-by: Andrew Morton Signed-off-by: Sasha Levin --- kernel/acct.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/acct.c b/kernel/acct.c index 13706356ec54..67bde1633d8f 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -350,6 +350,8 @@ static comp_t encode_comp_t(unsigned long value) exp++; } + if (exp > (((comp_t) ~0U) >> MANTSIZE)) + return (comp_t) ~0U; /* * Clean it up and polish it off. */ -- 2.35.1