From patchwork Thu Jan 5 22:15:37 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 13090596 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 E679CC3DA7A for ; Thu, 5 Jan 2023 22:15:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235750AbjAEWPr (ORCPT ); Thu, 5 Jan 2023 17:15:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50752 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235756AbjAEWPo (ORCPT ); Thu, 5 Jan 2023 17:15:44 -0500 Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 73F7D67BFF for ; Thu, 5 Jan 2023 14:15:43 -0800 (PST) Received: by mail-pl1-x635.google.com with SMTP id g16so31127489plq.12 for ; Thu, 05 Jan 2023 14:15:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=gsh4Qgz0dAZX19NkyGAdNILAtOkB8coB2LmFm1qOWdc=; b=oV/ftWoXv3dRTiE6dX1WBD6eNfMMqiCELaUuBnjdijiIdoiYax+ur+M02gXCd6s4yk 6tTWQm2p6KjtpIjdMLUnJeDQNOG5cCb9JMVL/n0ZN/4qyOnnNXvLlqNIF7OsexeBaFfk Qb9sVm1R4H9FDfZGo3RVLTklAb49inuJOUdiw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=gsh4Qgz0dAZX19NkyGAdNILAtOkB8coB2LmFm1qOWdc=; b=Csd2koMFbF+fl6+zJ1PvUwlpANjep1oCVQs5+HxK4UjsL/UvuR6ptTEAqN/ZsieX1X NTVUU5KT1GQauTkMu20GWDpfAl+c9+BmOlO9Rxc3Usly8C8v8w4SKP+oJt2LOaT0UTyr tRSCQRlDRpa1+P1mvToD/zyXMtgmisqWjbAw16lZ+nitL75qKEVGqSkvmf+TQ8DnK86D AJ8rMaamtrlAxURLAhnmqpPKb3MN9K+P2WuCu4TdHsuudeiZbI6k4dWe7IxzqiqsS7VM 1UwTs9Tf5jLzoGh932/xrvrbonEBjwY4hkMQK1JSUuJJOdr845R5rJ1V3Pxb/dgpP5S1 2sDw== X-Gm-Message-State: AFqh2krVcLePK8+gCnME5jB7CyqbrzY0xAdvpOJK8RmRCb0RjHCbGTdu XjrWlj+V1GQ9uvRFHYp3i+rYxg== X-Google-Smtp-Source: AMrXdXux4oWjJWim2VKtmkR/9QYi8fOUmvxp7vlXY4l+TZt19eWfsPAKmaCwaszvHrEZr4tLotPtMw== X-Received: by 2002:a17:902:a5c1:b0:189:62fd:140e with SMTP id t1-20020a170902a5c100b0018962fd140emr53604813plq.29.1672956942951; Thu, 05 Jan 2023 14:15:42 -0800 (PST) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id j9-20020a170902758900b00189c9f7fac1sm26604098pll.62.2023.01.05.14.15.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 05 Jan 2023 14:15:42 -0800 (PST) From: Kees Cook To: "David S. Miller" Cc: Kees Cook , Hideaki YOSHIFUJI , David Ahern , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "Gustavo A. R. Silva" , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH] net: ipv6: rpl_iptunnel: Replace 0-length arrays with flexible arrays Date: Thu, 5 Jan 2023 14:15:37 -0800 Message-Id: <20230105221533.never.711-kees@kernel.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2310; h=from:subject:message-id; bh=3B/MOywRgENsLrzur8E2ezmoeoBZ65hD9wrNoefThRA=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBjt0wI3l8J5ra3VVkkOUG6RTpzyYkw1RR7xoKFAzYa p0Tz86CJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCY7dMCAAKCRCJcvTf3G3AJtwIEA CYkkz4J2J4QmdXbnf9Fo8pZkJLgIDDofSjQQ9NE1J99qMUqlm8WGrBlWXyM4o7ODi57/x0BtIE4fO9 HPrHoYVhIEGkJjAGu+cbZ8PgBGUiV5mEUMtE57mKb8MeK7ZsX9AW7ylG6p9rpVDUtWsZA8fl2Jv8XU SVi5k2/nJC0db2Te/FC7E2y5kL1eFElzP5ehag7rghhrE6U+wNcddOFyBSEsJNota3Nj77SdndPNyP dWB5P06hMy4m/b7yeL99T4fhVhLrV2COVyPmUkHZMnTqY0p86u6DFIhNQEDxkolFDRW6wzZm9ywEgT TosmoI0UEAZrMZ+SopFduZvo4rqIg7tXjzqtBcrcb0Rre1Kv+wVaFEJePRGOJThiXbTfJvx7fyULp8 qwqedHcengFduTM4ue5yNPgDJy7Qh7Sm+AhPlffpeyoyB1regG53jgHNKYvjN65/ddW/W1DVrxPPWP woTJ2ETuPrUCF7qf24ZOSl4T71Fuf0tFmUuaelJWUuXd3b7+0BoxPvCQyF4zS5awcaTt91NdV/U8Qf bDR4RH/3QxYveZKZGFqj9cq1+G/vuNb+9I2Qv4ooIIcL3HTmN56jCZ+t2rbx528HNBF8Tmu/jhMdmR kYdbWVz4h9hYNEAFf0RfvSmdObGWQe6DolgRLrFvUvkpTBYwhhT82rDt1G/A== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org Zero-length arrays are deprecated[1]. Replace struct ipv6_rpl_sr_hdr's "segments" union of 0-length arrays with flexible arrays. Detected with GCC 13, using -fstrict-flex-arrays=3: In function 'rpl_validate_srh', inlined from 'rpl_build_state' at ../net/ipv6/rpl_iptunnel.c:96:7: ../net/ipv6/rpl_iptunnel.c:60:28: warning: array subscript is outside array bounds of 'struct in6_addr[0]' [-Warray-bounds=] 60 | if (ipv6_addr_type(&srh->rpl_segaddr[srh->segments_left - 1]) & | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In file included from ../include/net/rpl.h:12, from ../net/ipv6/rpl_iptunnel.c:13: ../include/uapi/linux/rpl.h: In function 'rpl_build_state': ../include/uapi/linux/rpl.h:40:33: note: while referencing 'addr' 40 | struct in6_addr addr[0]; | ^~~~ [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays Cc: "David S. Miller" Cc: Hideaki YOSHIFUJI Cc: David Ahern Cc: Eric Dumazet Cc: Jakub Kicinski Cc: Paolo Abeni Cc: "Gustavo A. R. Silva" Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook Reviewed-by: Gustavo A. R. Silva Reviewed-by: David Ahern --- include/uapi/linux/rpl.h | 4 ++-- net/ipv6/rpl_iptunnel.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/include/uapi/linux/rpl.h b/include/uapi/linux/rpl.h index 708adddf9f13..7c8970e5b84b 100644 --- a/include/uapi/linux/rpl.h +++ b/include/uapi/linux/rpl.h @@ -37,8 +37,8 @@ struct ipv6_rpl_sr_hdr { #endif union { - struct in6_addr addr[0]; - __u8 data[0]; + __DECLARE_FLEX_ARRAY(struct in6_addr, addr); + __DECLARE_FLEX_ARRAY(__u8, data); } segments; } __attribute__((packed)); diff --git a/net/ipv6/rpl_iptunnel.c b/net/ipv6/rpl_iptunnel.c index ff691d9f4a04..b1c028df686e 100644 --- a/net/ipv6/rpl_iptunnel.c +++ b/net/ipv6/rpl_iptunnel.c @@ -13,7 +13,7 @@ #include struct rpl_iptunnel_encap { - struct ipv6_rpl_sr_hdr srh[0]; + DECLARE_FLEX_ARRAY(struct ipv6_rpl_sr_hdr, srh); }; struct rpl_lwt {