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 18FBFC4332F for ; Sat, 17 Dec 2022 15:35:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230234AbiLQPfO (ORCPT ); Sat, 17 Dec 2022 10:35:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37940 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230288AbiLQPdm (ORCPT ); Sat, 17 Dec 2022 10:33:42 -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 A9A07167C0; Sat, 17 Dec 2022 07:29:24 -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 6BC2CB80123; Sat, 17 Dec 2022 15:29:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1228EC433F0; Sat, 17 Dec 2022 15:29:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671290962; bh=qR0vw+uQELOwhOUev5/wnJO2JEk9ykAYOvrnAJzGcKs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g5eyvnlKw8jePeaONi5vrZ4UCwL1qh1Mtu6ZqIC8hOfx9pbBjKHXXXtar1NR+UiVT yXR43aeB35nzXQ5JpYixu4gT4yGKe4S9PamHzYzSVFd5AGbB5ZdyQ7at1rIj2ebOTf Vfxnjw5rR2C4/rE94RYVhggFCP6KwJ5UWE/TNiGgphA9fRfCgrs/YPeOxq5+P57z5o RTpjB934NIWD+57n5ETVm8RxsYsec1hUUQN+CTuKg9an7w0A+okYFZkpBVMH1Em4hr +LLqfKP2gL2omOERsg9wVHfLwIKyOG16quwqMSnGAneeOTS2SarlVg8OaHQmP5QGx/ dSJtzBhpz78iQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Zheng Yejian , Hanjun Guo , Randy Dunlap , Vlastimil Babka , Zhang Jinhao , Andrew Morton , Sasha Levin , dave@stgolabs.net, tangmeng@uniontech.com, willy@infradead.org Subject: [PATCH AUTOSEL 5.15 09/10] acct: fix potential integer overflow in encode_comp_t() Date: Sat, 17 Dec 2022 10:28:59 -0500 Message-Id: <20221217152902.98870-9-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221217152902.98870-1-sashal@kernel.org> References: <20221217152902.98870-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 23a7ab8e6cbc..2b5cc63eb295 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -331,6 +331,8 @@ 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