Re: [PATCH net-next 5/6] ethtool: fec: sanitize ethtool_fecparam->fec

Hi Jakub,

url:    https://github.com/0day-ci/linux/commits/Jakub-Kicinski/ethtool-clarify-the-ethtool-FEC-interface/20210325-091411
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 69cdfb530f7b8b094e49555454869afc8140b1bb
config: x86_64-randconfig-m001-20210325 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <redacted>
Reported-by: Dan Carpenter <redacted>

smatch warnings:
net/ethtool/ioctl.c:2589 ethtool_set_fecparam() warn: bitwise AND condition is false here

vim +2589 net/ethtool/ioctl.c

1a5f3da20bd966 net/core/ethtool.c  Vidya Sagar Ravipati 2017-07-27  2579  static int ethtool_set_fecparam(struct net_device *dev, void __user *useraddr)
1a5f3da20bd966 net/core/ethtool.c  Vidya Sagar Ravipati 2017-07-27  2580  {
1a5f3da20bd966 net/core/ethtool.c  Vidya Sagar Ravipati 2017-07-27  2581  	struct ethtool_fecparam fecparam;
1a5f3da20bd966 net/core/ethtool.c  Vidya Sagar Ravipati 2017-07-27  2582  
1a5f3da20bd966 net/core/ethtool.c  Vidya Sagar Ravipati 2017-07-27  2583  	if (!dev->ethtool_ops->set_fecparam)
1a5f3da20bd966 net/core/ethtool.c  Vidya Sagar Ravipati 2017-07-27  2584  		return -EOPNOTSUPP;
1a5f3da20bd966 net/core/ethtool.c  Vidya Sagar Ravipati 2017-07-27  2585  
1a5f3da20bd966 net/core/ethtool.c  Vidya Sagar Ravipati 2017-07-27  2586  	if (copy_from_user(&fecparam, useraddr, sizeof(fecparam)))
1a5f3da20bd966 net/core/ethtool.c  Vidya Sagar Ravipati 2017-07-27  2587  		return -EFAULT;
1a5f3da20bd966 net/core/ethtool.c  Vidya Sagar Ravipati 2017-07-27  2588  
15beed7dba77ce net/ethtool/ioctl.c Jakub Kicinski       2021-03-24 @2589  	if (!fecparam.fec || fecparam.fec & ETHTOOL_FEC_NONE_BIT)
                                                                                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This should be if (!fecparam.fec || fecparam.fec & BIT(ETHTOOL_FEC_NONE_BIT))

15beed7dba77ce net/ethtool/ioctl.c Jakub Kicinski       2021-03-24  2590  		return -EINVAL;
15beed7dba77ce net/ethtool/ioctl.c Jakub Kicinski       2021-03-24  2591  
c405852e12f210 net/ethtool/ioctl.c Jakub Kicinski       2021-03-24  2592  	fecparam.active_fec = 0;
76d37e2ba4f23d net/ethtool/ioctl.c Jakub Kicinski       2021-03-24  2593  	fecparam.reserved = 0;
76d37e2ba4f23d net/ethtool/ioctl.c Jakub Kicinski       2021-03-24  2594  
1a5f3da20bd966 net/core/ethtool.c  Vidya Sagar Ravipati 2017-07-27  2595  	return dev->ethtool_ops->set_fecparam(dev, &fecparam);
1a5f3da20bd966 net/core/ethtool.c  Vidya Sagar Ravipati 2017-07-27  2596  }

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org