[linux-stable-rc:linux-4.19.y 2019/3658] include/linux/sunrpc/xdr.h:512:17: error: comparison is always false due to limited range of data type

kernel test robot
2022-08-20T09:37:33Z

Hi Dan,

FYI, the error/warning still remains.

tree: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-4.19.y
head: deac5288db671ab8cdd05be7ee0f0601c6692c6b
commit: 3a2789e8ccb4a3e2a631f6817a2d3bb98b8c4fd8 [2019/3658] NFSD: prevent integer overflow on 32 bit systems
config: sparc64-randconfig-s052-20220820 (https://download.01.org/0day-ci/archive/20220820/202208201701.arornb8Z-lkp@intel.com/config)
compiler: sparc64-linux-gcc (GCC) 12.1.0
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# apt-get install sparse
# sparse version: v0.6.4-39-gce1a6720-dirty
# https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git/commit/?id=3a2789e8ccb4a3e2a631f6817a2d3bb98b8c4fd8
git remote add linux-stable-rc https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
git fetch --no-tags linux-stable-rc linux-4.19.y
git checkout 3a2789e8ccb4a3e2a631f6817a2d3bb98b8c4fd8
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' 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@intel.com>

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:512:17: error: comparison is always false due to limited range of data type [-Werror=type-limits]
512 | if (len > SIZE_MAX / sizeof(*p))
| ^
In file included from include/linux/ethtool.h:17,
from include/linux/netdevice.h:41,
from include/net/sock.h:51,
from include/linux/tcp.h:23,
from include/linux/ipv6.h:87,
from include/net/ipv6.h:16,
from include/linux/sunrpc/clnt.h:28,
from include/linux/nfs_fs.h:32:
include/linux/compat.h: In function 'put_compat_sigset':
include/linux/compat.h:495:58: error: this statement may fall through [-Werror=implicit-fallthrough=]
495 | case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
| ~~~~~~~~~^~~~~~~~~~~~~
include/linux/compat.h:496:9: note: here
496 | case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
| ^~~~
include/linux/compat.h:496:58: error: this statement may fall through [-Werror=implicit-fallthrough=]
496 | case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
| ~~~~~~~~~^~~~~~~~~~~~~
include/linux/compat.h:497:9: note: here
497 | case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
| ^~~~
include/linux/compat.h:497:58: error: this statement may fall through [-Werror=implicit-fallthrough=]
497 | case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
| ~~~~~~~~~^~~~~~~~~~~~~
include/linux/compat.h:498:9: note: here
498 | case 1: v.sig[1] = (set->sig[0] >> 32); v.sig[0] = set->sig[0];
| ^~~~
cc1: all warnings being treated as errors

vim +512 include/linux/sunrpc/xdr.h

490
491 /**
492 * xdr_stream_decode_uint32_array - Decode variable length array of integers
493 * @xdr: pointer to xdr_stream
494 * @array: location to store the integer array or NULL
495 * @array_size: number of elements to store
496 *
497 * Return values:
498 * On success, returns number of elements stored in @array
499 * %-EBADMSG on XDR buffer overflow
500 * %-EMSGSIZE if the size of the array exceeds @array_size
501 */
502 static inline ssize_t
503 xdr_stream_decode_uint32_array(struct xdr_stream *xdr,
504 __u32 *array, size_t array_size)
505 {
506 __be32 *p;
507 __u32 len;
508 ssize_t retval;
509
510 if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
511 return -EBADMSG;
> 512 if (len > SIZE_MAX / sizeof(*p))
513 return -EBADMSG;
514 p = xdr_inline_decode(xdr, len * sizeof(*p));
515 if (unlikely(!p))
516 return -EBADMSG;
517 if (array == NULL)
518 return len;
519 if (len <= array_size) {
520 if (len < array_size)
521 memset(array+len, 0, (array_size-len)*sizeof(*array));
522 array_size = len;
523 retval = len;
524 } else
525 retval = -EMSGSIZE;
526 for (; array_size > 0; p++, array++, array_size--)
527 *array = be32_to_cpup(p);
528 return retval;
529 }
530 #endif /* __KERNEL__ */
531

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0-DAY CI Kernel Test Service