Re: [PATCH 4/4] net: improve the user pointer check in init_user_sockptr

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

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Hi Christoph,

I love your patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Christoph-Hellwig/sockptr_t-fixes/20200728-144019
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 5e619d73e6797ed9f2554a1bf996d52d8c91ca50
config: i386-randconfig-s031-20200728 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-14) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.2-94-geb6779f6-dirty
        # save the attached .config to linux build tree
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=i386 

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


sparse warnings: (new ones prefixed by >>)

>> net/ipv4/bpfilter/sockopt.c:68:56: sparse: sparse: dereference of noderef expression
>> net/ipv4/bpfilter/sockopt.c:68:56: sparse: sparse: dereference of noderef expression

vim +68 net/ipv4/bpfilter/sockopt.c

    59	
    60	int bpfilter_ip_get_sockopt(struct sock *sk, int optname,
    61				    char __user *user_optval, int __user *optlen)
    62	{
    63		sockptr_t optval;
    64		int err, len;
    65	
    66		if (get_user(len, optlen))
    67			return -EFAULT;
  > 68		err = init_user_sockptr(&optval, user_optval, *optlen);
    69		if (err)
    70			return err;
    71		return bpfilter_mbox_request(sk, optname, optval, len, false);
    72	}
    73	

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

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