[stable:linux-5.4.y 2861/5186] include/linux/sunrpc/xdr.h:539:17: error: comparison is always false due to limited range of data type

From: kernel test robot
Date: Thu Aug 25 2022 - 08:45:05 EST


Hi Dan,

FYI, the error/warning still remains.

tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git linux-5.4.y
head: 684cc17be897de3b0fd2e5a021a702f68046d9fe
commit: ce1aa09cc14ed625104acc2d487bd92b9a88efe2 [2861/5186] NFSD: prevent integer overflow on 32 bit systems
config: sparc64-randconfig-r003-20220823 (https://download.01.org/0day-ci/archive/20220825/202208252033.POQoHYcN-lkp@xxxxxxxxx/config)
compiler: sparc64-linux-gcc (GCC) 12.1.0
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
# https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/?id=ce1aa09cc14ed625104acc2d487bd92b9a88efe2
git remote add stable https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git
git fetch --no-tags stable linux-5.4.y
git checkout ce1aa09cc14ed625104acc2d487bd92b9a88efe2
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=sparc64 SHELL=/bin/bash arch/sparc/kernel/

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

All errors (new ones prefixed by >>):

In file included from include/linux/sunrpc/sched.h:19,
from include/linux/sunrpc/auth.h:15,
from include/linux/nfs_fs.h:31,
from arch/sparc/kernel/sys_sparc32.c:25:
include/linux/sunrpc/xdr.h: In function 'xdr_stream_decode_uint32_array':
>> include/linux/sunrpc/xdr.h:539:17: error: comparison is always false due to limited range of data type [-Werror=type-limits]
539 | if (len > SIZE_MAX / sizeof(*p))
| ^
cc1: all warnings being treated as errors

Kconfig warnings: (for reference only)
WARNING: unmet direct dependencies detected for FRAME_POINTER
Depends on [n]: DEBUG_KERNEL [=y] && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS [=n] || MCOUNT [=n]
Selected by [y]:
- LOCKDEP [=y] && DEBUG_KERNEL [=y] && LOCK_DEBUGGING_SUPPORT [=y] && !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86


vim +539 include/linux/sunrpc/xdr.h

517
518 /**
519 * xdr_stream_decode_uint32_array - Decode variable length array of integers
520 * @xdr: pointer to xdr_stream
521 * @array: location to store the integer array or NULL
522 * @array_size: number of elements to store
523 *
524 * Return values:
525 * On success, returns number of elements stored in @array
526 * %-EBADMSG on XDR buffer overflow
527 * %-EMSGSIZE if the size of the array exceeds @array_size
528 */
529 static inline ssize_t
530 xdr_stream_decode_uint32_array(struct xdr_stream *xdr,
531 __u32 *array, size_t array_size)
532 {
533 __be32 *p;
534 __u32 len;
535 ssize_t retval;
536
537 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
538 return -EBADMSG;
> 539 if (len > SIZE_MAX / sizeof(*p))
540 return -EBADMSG;
541 p = xdr_inline_decode(xdr, len * sizeof(*p));
542 if (unlikely(!p))
543 return -EBADMSG;
544 if (array == NULL)
545 return len;
546 if (len <= array_size) {
547 if (len < array_size)
548 memset(array+len, 0, (array_size-len)*sizeof(*array));
549 array_size = len;
550 retval = len;
551 } else
552 retval = -EMSGSIZE;
553 for (; array_size > 0; p++, array++, array_size--)
554 *array = be32_to_cpup(p);
555 return retval;
556 }
557 #endif /* __KERNEL__ */
558

--
0-DAY CI Kernel Test Service
https://01.org/lkp