From patchwork Sat Sep 11 13:19:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Len Baker X-Patchwork-Id: 12537679 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=-13.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 1DF11C433EF for ; Sat, 11 Sep 2021 13:22:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0690C611CC for ; Sat, 11 Sep 2021 13:22:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236543AbhIKNXR (ORCPT ); Sat, 11 Sep 2021 09:23:17 -0400 Received: from mout.gmx.net ([212.227.17.20]:35509 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237507AbhIKNVO (ORCPT ); Sat, 11 Sep 2021 09:21:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1631366392; bh=l59PM1Fs/cmKt8wqLqgWL72Gp/GHOpUwGSncn3oSEoI=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date; b=DbfOkvwS3dekgjP8N2b55KrobJfb9Wtz0XuFCJ0wvmVQGokNhYim4sRlDwnHf77LC g97myHz+QKVoaoJaTyK2Iy2ng7XFXPWLUmTST16Fxg+UhGRsq5tIeziMfXJpQtHvC4 +9aHVkh4ntkozBjXWKbzZY4lN3S6sOWpQxWTx81s= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from localhost.localdomain ([79.150.72.99]) by mail.gmx.net (mrgmx105 [212.227.17.174]) with ESMTPSA (Nemesis) id 1MZTqg-1mSwdd49xe-00WTYB; Sat, 11 Sep 2021 15:19:52 +0200 From: Len Baker To: Maxim Levitsky , Alex Dubov , Ulf Hansson Cc: Len Baker , Kees Cook , Tom Rix , linux-hardening@vger.kernel.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] memstick: jmb38x_ms: Prefer struct_size over open coded arithmetic Date: Sat, 11 Sep 2021 15:19:33 +0200 Message-Id: <20210911131933.2089-1-len.baker@gmx.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Provags-ID: V03:K1:c6Ig4Obe3Q3j3moUxcfS+LciEA5uOCXmbpNQ8tM6qr3ju/cJ2W9 QIOASDqowAyl+AetKcDTc3JOINMJkkUpBM9J1A5SYl5bXG9+P6nIWCtLkl/HY+C3XTvlgtt UAzLQI5lfOjt9S/pA4DixRbsIdzZ6zfirD8i7fiRgF/xYmVYhex4k+90eKsfi01mtg37P+F uBayeLNE/hFg+D1h50gTA== X-UI-Out-Filterresults: notjunk:1;V03:K0:rfH7G68vj+E=:8NkfttQKabHCymCsDppJ5q LpnweXmrTNuhOjN3P6qEadw0eQNs4XWOvtmEGY5SmbZivKA6KzGAk0hP+4XnM9Mluh8U14hLX 98/zOEOsZD1OOm3OhkN/mdPeVIn+wqst1TQp0xZ2fa51yHsRqV+lXlnu03TNqnWE9osdPsKmX DVeaX5wFt9XhGAyLwvjTIPMCihgK2sIAMnW5WnN5Gl1zZAzziQiNtBEFFv1WWoQU+IhPgxfZg C7dJASxOxf8m8MJ99Judu2Iur8p7jRP9Xzm/WWTn97ZiCxjBqN+NHtqsXbXQDhHUCtX1YHSPw HL0kHh7PGhlncIlfE9NMDUapRB95T/Tj/Nuv09y5WW5/BvSpZaGYWCf2b1aVmRBbGV3u6SD4h I3w8yoThdyxb2OaSWTx//FKid/qkTlD8qv28HlG6th4Q0dTHMx6jf/9bDf44ihcv6WN1Ov/Ae HkBlOnDV7X1si9+LIlh7+cNR1RIA8A0R8r70if7jcYdOoSDRc+eNhKNb4uOW0n4Sr8nNgVw6y 11zSnNt2skpEVANmdGmRhUXrt7aoI8YmvjjArvsY/Gg5v9viHfItVGqvcWauY1GPiUFNC6GIO V/F8SQRwXO8MZcaev7ctUdDcOFADBROhT2rr4oUip98M1NIP0NDw0wrQIhDak56JGQiPiffG8 ZVckQsCbHAH8ksswXYChsCyRNmBzwGptpd5mOh+ZGxUxhakwNrNwoLys+q41Q2n8V/Pu0Z06p VGiNvvbyeTRlYCA44luOoDjBCuA/yXuZTtWBkH1/sISu33QkL8cV1lEPM9yvLKngcr2iIKFBN lELm+KuV1U2rC2Rhia8fDLzxz6nA53HhozcFCK5ig+N0GSym1Im/d85EO5NRY9m0kXnRnKC0z tYg3ZOWa057N99J2EqqfCRFCbYXLbTwLmNSiprov0XeiJBgJ88Exr7IegGKanDKGwqFBrSydN U+oFOnVhkNrbbVpLwyAjK6Wzo7FTVzlRo5kfkiG1Qtsxrb8c6p3APxt8gjsnOTld2NSiVhKxg zyNhrkFVtOS3lUNTtokFx33ZJzxWoj5yxV0YnECevhuuBlfnJyxLAb/cdlUbXduriT6DMLxEX mV+Hty3Ya5mo7g= Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org As noted in the "Deprecated Interfaces, Language Features, Attributes, and Conventions" documentation [1], size calculations (especially multiplication) should not be performed in memory allocator (or similar) function arguments due to the risk of them overflowing. This could lead to values wrapping around and a smaller allocation being made than the caller was expecting. Using those allocations could lead to linear overflows of heap memory and other misbehaviors. So, use the struct_size() helper to do the arithmetic instead of the argument "size + count * size" in the kzalloc() function. [1] https://www.kernel.org/doc/html/v5.14/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments Signed-off-by: Len Baker --- drivers/memstick/host/jmb38x_ms.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) -- 2.25.1 diff --git a/drivers/memstick/host/jmb38x_ms.c b/drivers/memstick/host/jmb38x_ms.c index f9a93b0565e1..a7a0f0caea15 100644 --- a/drivers/memstick/host/jmb38x_ms.c +++ b/drivers/memstick/host/jmb38x_ms.c @@ -927,8 +927,7 @@ static int jmb38x_ms_probe(struct pci_dev *pdev, goto err_out_int; } - jm = kzalloc(sizeof(struct jmb38x_ms) - + cnt * sizeof(struct memstick_host *), GFP_KERNEL); + jm = kzalloc(struct_size(jm, hosts, cnt), GFP_KERNEL); if (!jm) { rc = -ENOMEM; goto err_out_int;