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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 12F91C4338F for ; Thu, 5 Aug 2021 11:37:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EF16960C51 for ; Thu, 5 Aug 2021 11:37:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240975AbhHELhP (ORCPT ); Thu, 5 Aug 2021 07:37:15 -0400 Received: from bilbo.ozlabs.org ([203.11.71.1]:53891 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240857AbhHELhO (ORCPT ); Thu, 5 Aug 2021 07:37:14 -0400 Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4GgRQx6y6Wz9sRR; Thu, 5 Aug 2021 21:36:57 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ellerman.id.au; s=201909; t=1628163418; bh=LUuDWZ6QjdYX5SUcL0rg4SU99LJt8O7kFIHfniH4Wkg=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=SF7x/1BvF/du6tR1e3AqhoEFXeAMJ23q3ppFOuDYEK6+ht3SZq2BGm0VpBTQhnKiX c69CtfwbXEyopOpWkMlhoaZaNy7MBcjvFgi441GQPs8JoNSbaypcrSiMU40xfYUL8t f9mZrC/0/S9Sd0Sks9Q6ztffcNH3z15sejK3Mrq6GIC9o5cgKjNUdNCU7s+JyZXP+k m7V2vyizjbFsWr3PDpb/VJj0/lHDkB5dWIo6L1vPnRk6HtSQ+cZceBM9r0fWUQuSIl t/rcwuCY/XD4brZ4tPPAIPKwBGgNhCg1BsOkubGmrACsiPv8a+bTpGKspwCElp7iAD /yfmCkkp5M+aw== From: Michael Ellerman To: Kees Cook , linux-hardening@vger.kernel.org Cc: Kees Cook , "Gustavo A. R. Silva" , Keith Packard , Greg Kroah-Hartman , Andrew Morton , linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-staging@lists.linux.dev, linux-block@vger.kernel.org, linux-kbuild@vger.kernel.org, clang-built-linux@googlegroups.com Subject: Re: [PATCH 58/64] powerpc: Split memset() to avoid multi-field overflow In-Reply-To: <20210727205855.411487-59-keescook@chromium.org> References: <20210727205855.411487-1-keescook@chromium.org> <20210727205855.411487-59-keescook@chromium.org> Date: Thu, 05 Aug 2021 21:36:54 +1000 Message-ID: <87czqsnmw9.fsf@mpe.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Kees Cook writes: > In preparation for FORTIFY_SOURCE performing compile-time and run-time > field bounds checking for memset(), avoid intentionally writing across > neighboring fields. > > Instead of writing across a field boundary with memset(), move the call > to just the array, and an explicit zeroing of the prior field. > > Signed-off-by: Kees Cook > --- > drivers/macintosh/smu.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/macintosh/smu.c b/drivers/macintosh/smu.c > index 94fb63a7b357..59ce431da7ef 100644 > --- a/drivers/macintosh/smu.c > +++ b/drivers/macintosh/smu.c > @@ -848,7 +848,8 @@ int smu_queue_i2c(struct smu_i2c_cmd *cmd) > cmd->read = cmd->info.devaddr & 0x01; > switch(cmd->info.type) { > case SMU_I2C_TRANSFER_SIMPLE: > - memset(&cmd->info.sublen, 0, 4); > + cmd->info.sublen = 0; > + memset(&cmd->info.subaddr, 0, 3); > break; > case SMU_I2C_TRANSFER_COMBINED: > cmd->info.devaddr &= 0xfe; > -- > 2.30.2 Reviewed-by: Michael Ellerman cheers