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=-8.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,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 65B78C43216 for ; Thu, 26 Aug 2021 05:32:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4AA956108D for ; Thu, 26 Aug 2021 05:32:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238759AbhHZFd0 (ORCPT ); Thu, 26 Aug 2021 01:33:26 -0400 Received: from home.keithp.com ([63.227.221.253]:59102 "EHLO elaine.keithp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235822AbhHZFdZ (ORCPT ); Thu, 26 Aug 2021 01:33:25 -0400 X-Greylist: delayed 493 seconds by postgrey-1.27 at vger.kernel.org; Thu, 26 Aug 2021 01:33:24 EDT Received: from localhost (localhost [127.0.0.1]) by elaine.keithp.com (Postfix) with ESMTP id 5899F3F3072E; Wed, 25 Aug 2021 22:24:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=keithp.com; s=mail; t=1629955441; bh=9PZ6q0rR03ga0cJLlX7wkSjnkm2X7nPpg5xxJCy9RtY=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=V8ZHAWsNxg4cKzN6mnE+JjdKstvoz5QndsaHqm/0JKqtYHx7qf+sik19WnSbpeZ6Q AjEX1Klqm4x12oAgQH8lJrLC6u/4pXIci4EaQ4RxiiP5jw2kJ+Wr1BlcxY8C2Wy4Fb jWWcjACtFjQ8oJwH37HJ6c1VpqU7hCwsS5ybTnP5lAV/3zY5d1sdDagmQ9vi3jIuy+ +aNC6ttZBX0IIhNSuXRK8/CLxra6k3qQh4vmIkuBLdI1dM2E+Madd2GgJ1+vrteow/ mf12Ssnv9TySnCx3Kuw4vVdulBma/XNZ1AJsO0j9bHMsWffgJiNgYOkatDiua0iEHW KwBc5Fi629JHw== X-Virus-Scanned: Debian amavisd-new at keithp.com Received: from elaine.keithp.com ([127.0.0.1]) by localhost (elaine.keithp.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id d8LHxscT6hWs; Wed, 25 Aug 2021 22:23:56 -0700 (PDT) Received: from keithp.com (koto.keithp.com [192.168.11.2]) by elaine.keithp.com (Postfix) with ESMTPSA id C066C3F3072D; Wed, 25 Aug 2021 22:23:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=keithp.com; s=mail; t=1629955436; bh=9PZ6q0rR03ga0cJLlX7wkSjnkm2X7nPpg5xxJCy9RtY=; h=From:To:Cc:Subject:In-Reply-To:References:Date:From; b=oucPIc+p1TEr9jHm30BEh6nsSTrl/DjfKsV2qOrmVf1DMQG6349VUmW+3mP9GkPUL I83NAfeJdVNAQulPEjD7Ix9GtzkxVOtuCnS0CPRIYVo9SJp4x3PsZAV1p6NNDeHXq/ Pvkro7bsTJKioLnocCmT9z4E0ITr88YmjIXCsx4OjlbFg31K5rB1VNwJFPKdtbo5B+ wgAwhV3gKYrPc9G+VvgOJO5hAdM4ZTbw91d0PzSsU+T1k5fE3VrZWyO/aC9xvXNFSi KVrT1uAFAENSHmXt2n1lMtYd2RbyVO6pV2gORcBCJ0iIFawEM3Cwmy0/lQqQH6aom9 27qjOJbYQhByQ== Received: by keithp.com (Postfix, from userid 1000) id E3F3E1E6011A; Wed, 25 Aug 2021 22:24:18 -0700 (PDT) From: Keith Packard To: Kees Cook , linux-kernel@vger.kernel.org Cc: Kees Cook , "Gustavo A. R. Silva" , Arnd Bergmann , Kalle Valo , "David S. Miller" , Jakub Kicinski , Nilesh Javali , Manish Rangankar , GR-QLogic-Storage-Upstream@marvell.com, "James E.J. Bottomley" , "Martin K. Petersen" , Larry Finger , Phillip Potter , Greg Kroah-Hartman , Florian Schilhabel , Johannes Berg , Christophe JAILLET , Fabio Aiuto , Ross Schmidt , Marco Cesati , ath10k@lists.infradead.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-scsi@vger.kernel.org, linux-staging@lists.linux.dev, Rasmus Villemoes , Dan Williams , Daniel Vetter , clang-built-linux@googlegroups.com, linux-hardening@vger.kernel.org Subject: Re: [PATCH v2 3/5] treewide: Replace 0-element memcpy() destinations with flexible arrays In-Reply-To: <20210826050458.1540622-4-keescook@chromium.org> References: <20210826050458.1540622-1-keescook@chromium.org> <20210826050458.1540622-4-keescook@chromium.org> Date: Wed, 25 Aug 2021 22:24:18 -0700 Message-ID: <87r1egpym5.fsf@keithp.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable Kees Cook writes: > In some cases, use of the flex_array() helper is needed when a flexible > array is part of a union. The code below seems to show that the helper is also needed when the flexible array is the only member of a struct? Or is this just an extension of the 'part of a union' clause? > @@ -160,7 +160,7 @@ struct bmi_cmd { >=20=20 > union bmi_resp { > struct { > - u8 payload[0]; > + DECLARE_FLEX_ARRAY(u8, payload); > } read_mem; > struct { > __le32 result; =2D-=20 =2Dkeith --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEw4O3eCVWE9/bQJ2R2yIaaQAAABEFAmEnJYIACgkQ2yIaaQAA ABFJwg/9HnuEf5sIRlyVndEk8XKVsPy1mM63I9dwsOPTB031099GdKund7uEfybJ 1kjf3GQv9nMAM0Cq3Uoiqfqv2liuTW2dGKBY2wHAVOtWjQXyTiN3NP3iNx1kVd7X txLF08RakTjjbca72QM9P47VuaJMHchiiYQfGrUxaQY9/lUuyR1DawpZLomXT9kV fUuBUpYUO/Xta1zs/e6IudCJRL0h6Hlk2nLqV+zrjTNsbEhI+Ztd0Lv40VrIVfUJ ZXMCNHomviUCwybnTodcUdtWYU5JqokjGWqYZawyErshiEew6AiM1e5CHkl0fDQU OUSteni1sY0nJ32L74MN0A2vjPcOeY3lzE8FTxeY7BzbAorxELYD4jBXhopA0+MW CPXS0xfn6crMm2vyFH+6YB2udPlLr1+n0qfxaYr36Tr+dZ81D0lJ5g5UjX4J6q3G nqx/vxHjWYvTQpHVZCstuABCHad/J/0X9SRS4xwu4983bMwDOCfKCkF+RNitHfpO /m+mzWJYEQokqKtj/V8i1PDUYhpWO9Kx7G2zQZ31le75zrcfKmBccid3m65Z0OAD e0w8NfJ1NDwSFTl4duKB8gE5gNKuppuzLlDBQWhrqIK+5mKCapZ0sCjSqJjVxNjK Q41Bm6/blVaF0IaP2fnjEbyQYhy9tbuVEwYZ630P5ctqCHxsZ40= =cojg -----END PGP SIGNATURE----- --=-=-=--