[ammarfaizi2-block:crng/random/jd/getrandom-batch 9/9] include/linux/fortify-string.h:47:33: warning: '__builtin_memset' pointer overflow between offset [0, 255] and size [2147483648, 4294967295]

[kernel test robot <lkp@intel.com>]

tree:   https://github.com/ammarfaizi2/linux-block crng/random/jd/getrandom-batch
head:   99a314f603c9cd173e6db2e3776eb76477283e1a
commit: 99a314f603c9cd173e6db2e3776eb76477283e1a [9/9] random: batch getrandom() output per-task
config: i386-allyesconfig (https://download.01.org/0day-ci/archive/20220803/202208030326.kgXt6SdF-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-3) 11.3.0
reproduce (this is a W=1 build):
        # https://github.com/ammarfaizi2/linux-block/commit/99a314f603c9cd173e6db2e3776eb76477283e1a
        git remote add ammarfaizi2-block https://github.com/ammarfaizi2/linux-block
        git fetch --no-tags ammarfaizi2-block crng/random/jd/getrandom-batch
        git checkout 99a314f603c9cd173e6db2e3776eb76477283e1a
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/char/

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <lkp@intel.com>

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/thread_info.h:12,
                    from include/linux/thread_info.h:60,
                    from arch/x86/include/asm/preempt.h:7,
                    from include/linux/preempt.h:78,
                    from include/linux/rcupdate.h:27,
                    from include/linux/rculist.h:11,
                    from include/linux/pid.h:5,
                    from include/linux/sched.h:14,
                    from include/linux/utsname.h:6,
                    from drivers/char/random.c:28:
   drivers/char/random.c: In function 'get_random_bytes_user':
>> include/linux/fortify-string.h:47:33: warning: '__builtin_memset' pointer overflow between offset [0, 255] and size [2147483648, 4294967295] [-Warray-bounds]
      47 | #define __underlying_memset     __builtin_memset
         |                                 ^
   include/linux/fortify-string.h:281:9: note: in expansion of macro '__underlying_memset'
     281 |         __underlying_memset(p, c, __fortify_size);                      \
         |         ^~~~~~~~~~~~~~~~~~~
   include/linux/fortify-string.h:288:25: note: in expansion of macro '__fortify_memset_chk'
     288 | #define memset(p, c, s) __fortify_memset_chk(p, c, s,                   \
         |                         ^~~~~~~~~~~~~~~~~~~~
   drivers/char/random.c:425:17: note: in expansion of macro 'memset'
     425 |                 memset(current->rng_batch.buf + current->rng_batch.position, 0, batch_len);
         |                 ^~~~~~


vim +/__builtin_memset +47 include/linux/fortify-string.h

3009f891bb9f32 Kees Cook      2021-08-02  30  
a28a6e860c6cf2 Francis Laniel 2021-02-25  31  #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
a28a6e860c6cf2 Francis Laniel 2021-02-25  32  extern void *__underlying_memchr(const void *p, int c, __kernel_size_t size) __RENAME(memchr);
a28a6e860c6cf2 Francis Laniel 2021-02-25  33  extern int __underlying_memcmp(const void *p, const void *q, __kernel_size_t size) __RENAME(memcmp);
a28a6e860c6cf2 Francis Laniel 2021-02-25  34  extern void *__underlying_memcpy(void *p, const void *q, __kernel_size_t size) __RENAME(memcpy);
a28a6e860c6cf2 Francis Laniel 2021-02-25  35  extern void *__underlying_memmove(void *p, const void *q, __kernel_size_t size) __RENAME(memmove);
a28a6e860c6cf2 Francis Laniel 2021-02-25  36  extern void *__underlying_memset(void *p, int c, __kernel_size_t size) __RENAME(memset);
a28a6e860c6cf2 Francis Laniel 2021-02-25  37  extern char *__underlying_strcat(char *p, const char *q) __RENAME(strcat);
a28a6e860c6cf2 Francis Laniel 2021-02-25  38  extern char *__underlying_strcpy(char *p, const char *q) __RENAME(strcpy);
a28a6e860c6cf2 Francis Laniel 2021-02-25  39  extern __kernel_size_t __underlying_strlen(const char *p) __RENAME(strlen);
a28a6e860c6cf2 Francis Laniel 2021-02-25  40  extern char *__underlying_strncat(char *p, const char *q, __kernel_size_t count) __RENAME(strncat);
a28a6e860c6cf2 Francis Laniel 2021-02-25  41  extern char *__underlying_strncpy(char *p, const char *q, __kernel_size_t size) __RENAME(strncpy);
a28a6e860c6cf2 Francis Laniel 2021-02-25  42  #else
a28a6e860c6cf2 Francis Laniel 2021-02-25  43  #define __underlying_memchr	__builtin_memchr
a28a6e860c6cf2 Francis Laniel 2021-02-25  44  #define __underlying_memcmp	__builtin_memcmp
a28a6e860c6cf2 Francis Laniel 2021-02-25  45  #define __underlying_memcpy	__builtin_memcpy
a28a6e860c6cf2 Francis Laniel 2021-02-25  46  #define __underlying_memmove	__builtin_memmove
a28a6e860c6cf2 Francis Laniel 2021-02-25 @47  #define __underlying_memset	__builtin_memset
a28a6e860c6cf2 Francis Laniel 2021-02-25  48  #define __underlying_strcat	__builtin_strcat
a28a6e860c6cf2 Francis Laniel 2021-02-25  49  #define __underlying_strcpy	__builtin_strcpy
a28a6e860c6cf2 Francis Laniel 2021-02-25  50  #define __underlying_strlen	__builtin_strlen
a28a6e860c6cf2 Francis Laniel 2021-02-25  51  #define __underlying_strncat	__builtin_strncat
a28a6e860c6cf2 Francis Laniel 2021-02-25  52  #define __underlying_strncpy	__builtin_strncpy
a28a6e860c6cf2 Francis Laniel 2021-02-25  53  #endif
a28a6e860c6cf2 Francis Laniel 2021-02-25  54  

:::::: The code at line 47 was first introduced by commit
:::::: a28a6e860c6cf231cf3c5171c75c342adcd00406 string.h: move fortified functions definitions in a dedicated header.

:::::: TO: Francis Laniel <laniel_francis@privacyrequired.com>
:::::: CC: Linus Torvalds <torvalds@linux-foundation.org>

-- 
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