Hi Phil,

[FYI, it's a private test report for your RFC patch.]
[auto build test WARNING on nf-next/master]

url:    https://github.com/intel-lab-lkp/linux/commits/Phil-Sutter/netfilter-nf_tables-Compatibility-interface-for-nft_rule/20221105-062055
base:   https://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next.git master
patch link:    https://lore.kernel.org/r/20221104221827.30335-1-phil%40nwl.cc
patch subject: [nf-next RFC] netfilter: nf_tables: Compatibility interface for nft_rule
config: i386-randconfig-a013
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
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://github.com/intel-lab-lkp/linux/commit/9224fbbb5432ef777c5598b3533b7637cf5e8099
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Phil-Sutter/netfilter-nf_tables-Compatibility-interface-for-nft_rule/20221105-062055
        git checkout 9224fbbb5432ef777c5598b3533b7637cf5e8099
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash net/netfilter/

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 >>):

>> net/netfilter/nf_tables_api.c:3469:17: warning: variable 'err' is uninitialized when used here [-Wuninitialized]
           return ERR_PTR(err);
                          ^~~
   net/netfilter/nf_tables_api.c:3415:9: note: initialize the variable 'err' to silence this warning
           int err, rem;
                  ^
                   = 0
   1 warning generated.


vim +/err +3469 net/netfilter/nf_tables_api.c

  3408	
  3409	static struct nft_compat_expr *
  3410	nft_parse_compat_exprs_nla(const struct nlattr *nla)
  3411	{
  3412		struct nft_compat_expr *compat_exprs, *cur;
  3413		int idx = 0, num_exprs = 0;
  3414		struct nlattr *tmp;
  3415		int err, rem;
  3416	
  3417		nla = nla_find_nested(nla, NFTA_RULE_COMPAT_EXPRESSIONS);
  3418		if (!nla)
  3419			return NULL;
  3420	
  3421		nla_for_each_nested(tmp, nla, rem)
  3422			num_exprs++;
  3423	
  3424		if (!num_exprs)
  3425			return NULL;
  3426	
  3427		compat_exprs = kvmalloc_array(num_exprs + 1,
  3428					      sizeof(*compat_exprs), GFP_KERNEL);
  3429		if (!compat_exprs)
  3430			return ERR_PTR(-ENOMEM);
  3431	
  3432		cur = compat_exprs;
  3433		nla_for_each_nested(tmp, nla, rem) {
  3434			struct nlattr *tb[NFTA_RULE_COMPAT_EXPR_MAX + 1];
  3435			int err;
  3436	
  3437			if (idx >= NFT_RULE_MAXEXPRS)
  3438				return ERR_PTR(-ENOMEM);
  3439	
  3440			err = nla_parse_nested_deprecated(tb, NFTA_RULE_COMPAT_EXPR_MAX,
  3441							  tmp, nft_rule_compat_expression_policy, NULL);
  3442			if (err < 0)
  3443				return ERR_PTR(err);
  3444	
  3445			if (!tb[NFTA_RULE_COMPAT_EXPR_POS] ||
  3446			    !tb[NFTA_RULE_COMPAT_EXPR_LEN] ||
  3447			    !tb[NFTA_RULE_COMPAT_EXPR_INFO]) {
  3448				err = -EINVAL;
  3449				goto out_free;
  3450			}
  3451	
  3452			cur->pos = nla_get_u32(tb[NFTA_RULE_COMPAT_EXPR_POS]);
  3453			cur->len = nla_get_u32(tb[NFTA_RULE_COMPAT_EXPR_LEN]);
  3454			cur->dlen = nla_len(tb[NFTA_RULE_COMPAT_EXPR_INFO]);
  3455			cur->data = kvmalloc(cur->dlen, GFP_KERNEL);
  3456			if (!cur->data) {
  3457				err = -ENOMEM;
  3458				goto out_free;
  3459			}
  3460	
  3461			nla_memcpy(cur->data,
  3462				   tb[NFTA_RULE_COMPAT_EXPR_INFO], cur->dlen);
  3463			cur++;
  3464		}
  3465		cur->len = 0;
  3466		return compat_exprs;
  3467	out_free:
  3468		kfree(compat_exprs);
> 3469		return ERR_PTR(err);
  3470	}
  3471	

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