Hi Florian, I love your patch! Perhaps something to improve: [auto build test WARNING on nf-next/master] url: https://github.com/0day-ci/linux/commits/Florian-Westphal/netfilter-add-h... base: https://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next.git master config: x86_64-randconfig-r026-20210522 (attached as .config) compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project e84a9b9bb3051c35dea993cdad7b3d2575638f85) 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 # install x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://github.com/0day-ci/linux/commit/0d9a4c5b44ef1ad2d9ed5c4c8cea7eae2... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Florian-Westphal/netfilter-add-hook-dump-feature/20210522-225655 git checkout 0d9a4c5b44ef1ad2d9ed5c4c8cea7eae29560706 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): if (!nlh) ^~~~ net/netfilter/nf_tables_api.c:8006:9: note: uninitialized use occurs here return ret; ^~~ net/netfilter/nf_tables_api.c:7991:2: note: remove the 'if' if its condition is always false if (!nlh) ^~~~~~~~~ net/netfilter/nf_tables_api.c:7987:9: note: initialize the variable 'ret' to silence this warning int ret; ^ = 0 1 warning generated. vim +7991 net/netfilter/nf_tables_api.c 7979 7980 static int nf_tables_dump_one_hook(struct sk_buff *nlskb, 7981 const struct nft_dump_hooks_data *ctx, 7982 const struct nf_hook_ops *ops) 7983 { 7984 unsigned int portid = NETLINK_CB(nlskb).portid; 7985 struct net *net = sock_net(nlskb->sk); 7986 struct nlmsghdr *nlh; 7987 int ret; 7988 7989 nlh = nfnl_msg_put(nlskb, portid, ctx->seq, NFT_MSG_GETNFHOOKS, 7990 NLM_F_MULTI, ops->pf, NFNETLINK_V0, nft_base_seq(net)); 7992 goto nla_put_failure; 7993 7994 ret = nla_put_be32(nlskb, NFTA_HOOK_HOOKNUM, htonl(ops->hooknum)); 7995 if (ret) 7996 goto nla_put_failure; 7997 7998 ret = nla_put_be32(nlskb, NFTA_HOOK_PRIORITY, htonl(ops->priority)); 7999 if (ret) 8000 goto nla_put_failure; 8001 8002 nlmsg_end(nlskb, nlh); 8003 return 0; 8004 nla_put_failure: 8005 nlmsg_trim(nlskb, nlh); 8006 return ret; 8007 } 8008 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org