[kbuild-all] [linux-next:master 4586/5417] include/linux/fortify-string.h:336:4: error: call to __read_overflow2_field declared with 'warning' attribute: detected read beyond size of field (2nd parameter); maybe use struct_group()?

tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 6d9bd4ad4ca08b1114e814c2c42383b8b13be631 commit: e9ebe9d15a978c03dbf5a1d091399d77b893a0bd [4586/5417] fortify: Add Clang support config: arm-randconfig-c002-20220213 (https://download.01.org/0day-ci/archive/20220213/202202132020.DM0CzXLY-lk...) compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project 478c237e21b2c3a83e46f26fcbeb3876682f9b14) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install arm cross compiling tool for clang build # apt-get install binutils-arm-linux-gnueabi # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commi... git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout e9ebe9d15a978c03dbf5a1d091399d77b893a0bd # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash drivers/nfc/pn533/ drivers/scsi/libfc/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): In file included from drivers/nfc/pn533/pn533.c:9: In file included from include/linux/device.h:15: In file included from include/linux/dev_printk.h:16: In file included from include/linux/ratelimit.h:6: In file included from include/linux/sched.h:14: In file included from include/linux/pid.h:5: In file included from include/linux/rculist.h:11: In file included from include/linux/rcupdate.h:29: In file included from include/linux/lockdep.h:14: In file included from include/linux/smp.h:13: In file included from include/linux/cpumask.h:12: In file included from include/linux/bitmap.h:11: In file included from include/linux/string.h:253: __read_overflow2_field(q_size_field, size); ^ 2 errors generated. -- In file included from drivers/scsi/libfc/fc_elsct.c:17: In file included from include/scsi/libfc.h:11: In file included from include/linux/timer.h:8: In file included from include/linux/debugobjects.h:6: In file included from include/linux/spinlock.h:62: In file included from include/linux/lockdep.h:14: In file included from include/linux/smp.h:13: In file included from include/linux/cpumask.h:12: In file included from include/linux/bitmap.h:11: In file included from include/linux/string.h:253: __write_overflow_field(p_size_field, size); ^ 2 errors generated. vim +/warning +336 include/linux/fortify-string.h 45e31710b1ca2b Kees Cook 2021-06-16 267 45e31710b1ca2b Kees Cook 2021-06-16 268 /* 45e31710b1ca2b Kees Cook 2021-06-16 269 * __builtin_object_size() must be captured here to avoid evaluating argument 45e31710b1ca2b Kees Cook 2021-06-16 270 * side-effects further into the macro layers. 45e31710b1ca2b Kees Cook 2021-06-16 271 */ 45e31710b1ca2b Kees Cook 2021-06-16 272 #define memset(p, c, s) __fortify_memset_chk(p, c, s, \ 45e31710b1ca2b Kees Cook 2021-06-16 273 __builtin_object_size(p, 0), __builtin_object_size(p, 1)) a28a6e860c6cf2 Francis Laniel 2021-02-25 274 9b106a9037d705 Kees Cook 2021-04-20 275 /* 9b106a9037d705 Kees Cook 2021-04-20 276 * To make sure the compiler can enforce protection against buffer overflows, 9b106a9037d705 Kees Cook 2021-04-20 277 * memcpy(), memmove(), and memset() must not be used beyond individual 9b106a9037d705 Kees Cook 2021-04-20 278 * struct members. If you need to copy across multiple members, please use 9b106a9037d705 Kees Cook 2021-04-20 279 * struct_group() to create a named mirror of an anonymous struct union. 9b106a9037d705 Kees Cook 2021-04-20 280 * (e.g. see struct sk_buff.) Read overflow checking is currently only 9b106a9037d705 Kees Cook 2021-04-20 281 * done when a write overflow is also present, or when building with W=1. 9b106a9037d705 Kees Cook 2021-04-20 282 * 9b106a9037d705 Kees Cook 2021-04-20 283 * Mitigation coverage matrix 9b106a9037d705 Kees Cook 2021-04-20 284 * Bounds checking at: 9b106a9037d705 Kees Cook 2021-04-20 285 * +-------+-------+-------+-------+ 9b106a9037d705 Kees Cook 2021-04-20 286 * | Compile time | Run time | 9b106a9037d705 Kees Cook 2021-04-20 287 * memcpy() argument sizes: | write | read | write | read | 9b106a9037d705 Kees Cook 2021-04-20 288 * dest source length +-------+-------+-------+-------+ 9b106a9037d705 Kees Cook 2021-04-20 289 * memcpy(known, known, constant) | y | y | n/a | n/a | 9b106a9037d705 Kees Cook 2021-04-20 290 * memcpy(known, unknown, constant) | y | n | n/a | V | 9b106a9037d705 Kees Cook 2021-04-20 291 * memcpy(known, known, dynamic) | n | n | B | B | 9b106a9037d705 Kees Cook 2021-04-20 292 * memcpy(known, unknown, dynamic) | n | n | B | V | 9b106a9037d705 Kees Cook 2021-04-20 293 * memcpy(unknown, known, constant) | n | y | V | n/a | 9b106a9037d705 Kees Cook 2021-04-20 294 * memcpy(unknown, unknown, constant) | n | n | V | V | 9b106a9037d705 Kees Cook 2021-04-20 295 * memcpy(unknown, known, dynamic) | n | n | V | B | 9b106a9037d705 Kees Cook 2021-04-20 296 * memcpy(unknown, unknown, dynamic) | n | n | V | V | 9b106a9037d705 Kees Cook 2021-04-20 297 * +-------+-------+-------+-------+ 9b106a9037d705 Kees Cook 2021-04-20 298 * 9b106a9037d705 Kees Cook 2021-04-20 299 * y = perform deterministic compile-time bounds checking 9b106a9037d705 Kees Cook 2021-04-20 300 * n = cannot perform deterministic compile-time bounds checking 9b106a9037d705 Kees Cook 2021-04-20 301 * n/a = no run-time bounds checking needed since compile-time deterministic 9b106a9037d705 Kees Cook 2021-04-20 302 * B = can perform run-time bounds checking (currently unimplemented) 9b106a9037d705 Kees Cook 2021-04-20 303 * V = vulnerable to run-time overflow (will need refactoring to solve) 9b106a9037d705 Kees Cook 2021-04-20 304 * 9b106a9037d705 Kees Cook 2021-04-20 305 */ 9b106a9037d705 Kees Cook 2021-04-20 306 __FORTIFY_INLINE void fortify_memcpy_chk(__kernel_size_t size, 9b106a9037d705 Kees Cook 2021-04-20 307 const size_t p_size, 9b106a9037d705 Kees Cook 2021-04-20 308 const size_t q_size, 9b106a9037d705 Kees Cook 2021-04-20 309 const size_t p_size_field, 9b106a9037d705 Kees Cook 2021-04-20 310 const size_t q_size_field, 9b106a9037d705 Kees Cook 2021-04-20 311 const char *func) a28a6e860c6cf2 Francis Laniel 2021-02-25 312 { a28a6e860c6cf2 Francis Laniel 2021-02-25 313 if (__builtin_constant_p(size)) { 9b106a9037d705 Kees Cook 2021-04-20 314 /* 9b106a9037d705 Kees Cook 2021-04-20 315 * Length argument is a constant expression, so we 9b106a9037d705 Kees Cook 2021-04-20 316 * can perform compile-time bounds checking where 9b106a9037d705 Kees Cook 2021-04-20 317 * buffer sizes are known. 9b106a9037d705 Kees Cook 2021-04-20 318 */ 9b106a9037d705 Kees Cook 2021-04-20 319 9b106a9037d705 Kees Cook 2021-04-20 320 /* Error when size is larger than enclosing struct. */ 9b106a9037d705 Kees Cook 2021-04-20 321 if (p_size > p_size_field && p_size < size) a28a6e860c6cf2 Francis Laniel 2021-02-25 322 __write_overflow(); 9b106a9037d705 Kees Cook 2021-04-20 323 if (q_size > q_size_field && q_size < size) a28a6e860c6cf2 Francis Laniel 2021-02-25 324 __read_overflow2(); 9b106a9037d705 Kees Cook 2021-04-20 325 9b106a9037d705 Kees Cook 2021-04-20 326 /* Warn when write size argument larger than dest field. */ 9b106a9037d705 Kees Cook 2021-04-20 327 if (p_size_field < size) 9b106a9037d705 Kees Cook 2021-04-20 @328 __write_overflow_field(p_size_field, size); 9b106a9037d705 Kees Cook 2021-04-20 329 /* 9b106a9037d705 Kees Cook 2021-04-20 330 * Warn for source field over-read when building with W=1 9b106a9037d705 Kees Cook 2021-04-20 331 * or when an over-write happened, so both can be fixed at 9b106a9037d705 Kees Cook 2021-04-20 332 * the same time. 9b106a9037d705 Kees Cook 2021-04-20 333 */ 9b106a9037d705 Kees Cook 2021-04-20 334 if ((IS_ENABLED(KBUILD_EXTRA_WARN1) || p_size_field < size) && 9b106a9037d705 Kees Cook 2021-04-20 335 q_size_field < size) 9b106a9037d705 Kees Cook 2021-04-20 @336 __read_overflow2_field(q_size_field, size); a28a6e860c6cf2 Francis Laniel 2021-02-25 337 } 9b106a9037d705 Kees Cook 2021-04-20 338 /* 9b106a9037d705 Kees Cook 2021-04-20 339 * At this point, length argument may not be a constant expression, 9b106a9037d705 Kees Cook 2021-04-20 340 * so run-time bounds checking can be done where buffer sizes are 9b106a9037d705 Kees Cook 2021-04-20 341 * known. (This is not an "else" because the above checks may only 9b106a9037d705 Kees Cook 2021-04-20 342 * be compile-time warnings, and we want to still warn for run-time 9b106a9037d705 Kees Cook 2021-04-20 343 * overflows.) 9b106a9037d705 Kees Cook 2021-04-20 344 */ 9b106a9037d705 Kees Cook 2021-04-20 345 9b106a9037d705 Kees Cook 2021-04-20 346 /* 9b106a9037d705 Kees Cook 2021-04-20 347 * Always stop accesses beyond the struct that contains the 9b106a9037d705 Kees Cook 2021-04-20 348 * field, when the buffer's remaining size is known. 9b106a9037d705 Kees Cook 2021-04-20 349 * (The -1 test is to optimize away checks where the buffer 9b106a9037d705 Kees Cook 2021-04-20 350 * lengths are unknown.) 9b106a9037d705 Kees Cook 2021-04-20 351 */ 9b106a9037d705 Kees Cook 2021-04-20 352 if ((p_size != (size_t)(-1) && p_size < size) || 9b106a9037d705 Kees Cook 2021-04-20 353 (q_size != (size_t)(-1) && q_size < size)) 9b106a9037d705 Kees Cook 2021-04-20 354 fortify_panic(func); a28a6e860c6cf2 Francis Laniel 2021-02-25 355 } a28a6e860c6cf2 Francis Laniel 2021-02-25 356 :::::: The code at line 336 was first introduced by commit :::::: 9b106a9037d705d0c5cbc747b6fed7cbb33b0e00 fortify: Detect struct member overflows in memcpy() at compile-time :::::: TO: Kees Cook <keescook(a)chromium.org&gt; :::::: CC: Kees Cook <keescook(a)chromium.org&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org