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 0FB91C433EF for ; Sun, 27 Mar 2022 16:46:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236077AbiC0Qr4 (ORCPT ); Sun, 27 Mar 2022 12:47:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37160 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233381AbiC0Qry (ORCPT ); Sun, 27 Mar 2022 12:47:54 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4A35B13CED for ; Sun, 27 Mar 2022 09:46:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1648399575; x=1679935575; h=date:from:to:cc:subject:message-id:mime-version; bh=XVjQIJQWU4zdDML3/4MxnSO2eQb5MByU3lPMrxh6eLw=; b=WhN2LRnnBVQcjkRr1faq41pOV/rolDKjLaJr8KLt128EgMv1thyqr7K4 OcwO7Kc3hx+ydLEhSYeqLAwmTFMGYCU/x3DDfXUJUeJbYNEcmTxunZmZ9 v9q8scrIdPiAMh9mY9JYN6/SL0nR0H4bocmV9qLA6kbg9bQJeXIqH2gxc Js4ChTadAdGV96rM3pFQA8jaw6+bBiZouS0jBUv2IUo/VTrNmu7ubs2fm /YZGiLl29N2cWEAjorTdMBsFNUYRoaDFfiS9rOBsK4Xgp/nzLvyerjhtl m7BIt1ThuvS7qFyL4pXrh8i4iKhV/VPWL+8++5CiL8mSfUqjJAnSRoZVM A==; X-IronPort-AV: E=McAfee;i="6200,9189,10299"; a="256437244" X-IronPort-AV: E=Sophos;i="5.90,215,1643702400"; d="scan'208";a="256437244" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Mar 2022 09:46:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,215,1643702400"; d="scan'208";a="650840098" Received: from lkp-server02.sh.intel.com (HELO 89b41b6ae01c) ([10.239.97.151]) by orsmga004.jf.intel.com with ESMTP; 27 Mar 2022 09:46:13 -0700 Received: from kbuild by 89b41b6ae01c with local (Exim 4.92) (envelope-from ) id 1nYW1s-0001FG-U3; Sun, 27 Mar 2022 16:46:12 +0000 Date: Mon, 28 Mar 2022 00:46:04 +0800 From: kernel test robot To: Kees Cook Cc: kbuild-all@lists.01.org, linux-kernel@vger.kernel.org Subject: include/linux/fortify-string.h:275:4: warning: call to '__read_overflow2_field' declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? Message-ID: <202203280039.25eZrV5Z-lkp@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Kees, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: f022814633e1c600507b3a99691b4d624c2813f0 commit: f68f2ff91512c199ec24883001245912afc17873 fortify: Detect struct member overflows in memcpy() at compile-time date: 6 weeks ago config: i386-randconfig-a003 (https://download.01.org/0day-ci/archive/20220328/202203280039.25eZrV5Z-lkp@intel.com/config) compiler: gcc-9 (Ubuntu 9.4.0-1ubuntu1~20.04.1) 9.4.0 reproduce (this is a W=1 build): # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f68f2ff91512c199ec24883001245912afc17873 git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout f68f2ff91512c199ec24883001245912afc17873 # save the config file to linux build tree mkdir build_dir make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash net/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>): In file included from include/linux/string.h:253, from arch/x86/include/asm/page_32.h:22, from arch/x86/include/asm/page.h:14, from arch/x86/include/asm/processor.h:19, from arch/x86/include/asm/timex.h:5, from include/linux/timex.h:65, from include/linux/time32.h:13, from include/linux/time.h:60, from include/linux/skbuff.h:15, from net/core/flow_dissector.c:3: In function 'fortify_memcpy_chk', inlined from '__skb_flow_dissect' at net/core/flow_dissector.c:1034:3: >> include/linux/fortify-string.h:275:4: warning: call to '__read_overflow2_field' declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Wattribute-warning] 275 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ vim +/__read_overflow2_field +275 include/linux/fortify-string.h 213 214 /* 215 * To make sure the compiler can enforce protection against buffer overflows, 216 * memcpy(), memmove(), and memset() must not be used beyond individual 217 * struct members. If you need to copy across multiple members, please use 218 * struct_group() to create a named mirror of an anonymous struct union. 219 * (e.g. see struct sk_buff.) Read overflow checking is currently only 220 * done when a write overflow is also present, or when building with W=1. 221 * 222 * Mitigation coverage matrix 223 * Bounds checking at: 224 * +-------+-------+-------+-------+ 225 * | Compile time | Run time | 226 * memcpy() argument sizes: | write | read | write | read | 227 * dest source length +-------+-------+-------+-------+ 228 * memcpy(known, known, constant) | y | y | n/a | n/a | 229 * memcpy(known, unknown, constant) | y | n | n/a | V | 230 * memcpy(known, known, dynamic) | n | n | B | B | 231 * memcpy(known, unknown, dynamic) | n | n | B | V | 232 * memcpy(unknown, known, constant) | n | y | V | n/a | 233 * memcpy(unknown, unknown, constant) | n | n | V | V | 234 * memcpy(unknown, known, dynamic) | n | n | V | B | 235 * memcpy(unknown, unknown, dynamic) | n | n | V | V | 236 * +-------+-------+-------+-------+ 237 * 238 * y = perform deterministic compile-time bounds checking 239 * n = cannot perform deterministic compile-time bounds checking 240 * n/a = no run-time bounds checking needed since compile-time deterministic 241 * B = can perform run-time bounds checking (currently unimplemented) 242 * V = vulnerable to run-time overflow (will need refactoring to solve) 243 * 244 */ 245 __FORTIFY_INLINE void fortify_memcpy_chk(__kernel_size_t size, 246 const size_t p_size, 247 const size_t q_size, 248 const size_t p_size_field, 249 const size_t q_size_field, 250 const char *func) 251 { 252 if (__builtin_constant_p(size)) { 253 /* 254 * Length argument is a constant expression, so we 255 * can perform compile-time bounds checking where 256 * buffer sizes are known. 257 */ 258 259 /* Error when size is larger than enclosing struct. */ 260 if (p_size > p_size_field && p_size < size) 261 __write_overflow(); 262 if (q_size > q_size_field && q_size < size) 263 __read_overflow2(); 264 265 /* Warn when write size argument larger than dest field. */ 266 if (p_size_field < size) 267 __write_overflow_field(p_size_field, size); 268 /* 269 * Warn for source field over-read when building with W=1 270 * or when an over-write happened, so both can be fixed at 271 * the same time. 272 */ 273 if ((IS_ENABLED(KBUILD_EXTRA_WARN1) || p_size_field < size) && 274 q_size_field < size) > 275 __read_overflow2_field(q_size_field, size); 276 } 277 /* 278 * At this point, length argument may not be a constant expression, 279 * so run-time bounds checking can be done where buffer sizes are 280 * known. (This is not an "else" because the above checks may only 281 * be compile-time warnings, and we want to still warn for run-time 282 * overflows.) 283 */ 284 285 /* 286 * Always stop accesses beyond the struct that contains the 287 * field, when the buffer's remaining size is known. 288 * (The -1 test is to optimize away checks where the buffer 289 * lengths are unknown.) 290 */ 291 if ((p_size != (size_t)(-1) && p_size < size) || 292 (q_size != (size_t)(-1) && q_size < size)) 293 fortify_panic(func); 294 } 295 -- 0-DAY CI Kernel Test Service https://01.org/lkp