net/netfilter/nfnetlink_cthelper.c:227:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true

net/netfilter/nfnetlink_cthelper.c:227:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true

[kernel test robot]

tree:   https://github.com/intel-lab-lkp/linux/commits/Pablo-Neira-Ayuso/netfilter-nf_conntrack_helper-dynamically-allocate-struct-nf_conntrack_helper/20260602-061630
head:   739a05785415ce5213468185673fa33bae0e8306
commit: fe02ae4335b9628202025ecd6821fffb1edaed32 netfilter: nf_conntrack_helper: dynamically allocate struct nf_conntrack_helper
date:   9 days ago
config: x86_64-rhel-9.4-rust (https://download.01.org/0day-ci/archive/20260611/202606110148.Pn8XckYm-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project f43d6834093b19baf79beda8c0337ab020ac5f17)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260611/202606110148.Pn8XckYm-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202606110148.Pn8XckYm-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> net/netfilter/nfnetlink_cthelper.c:227:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
     227 |         if (!helper)
         |             ^~~~~~~
   net/netfilter/nfnetlink_cthelper.c:280:9: note: uninitialized use occurs here
     280 |         return ret;
         |                ^~~
   net/netfilter/nfnetlink_cthelper.c:227:2: note: remove the 'if' if its condition is always false
     227 |         if (!helper)
         |         ^~~~~~~~~~~~
     228 |                 goto err_cth;
         |                 ~~~~~~~~~~~~
   net/netfilter/nfnetlink_cthelper.c:217:9: note: initialize the variable 'ret' to silence this warning
     217 |         int ret;
         |                ^
         |                 = 0
   1 warning generated.


vim +227 net/netfilter/nfnetlink_cthelper.c

   209	
   210	static int
   211	nfnl_cthelper_create(const struct nlattr * const tb[],
   212			     struct nf_conntrack_tuple *tuple)
   213	{
   214		struct nf_conntrack_helper *helper;
   215		struct nfnl_cthelper *nfcth;
   216		unsigned int size;
   217		int ret;
   218	
   219		if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN])
   220			return -EINVAL;
   221	
   222		nfcth = kzalloc_obj(*nfcth, GFP_KERNEL_ACCOUNT);
   223		if (nfcth == NULL)
   224			return -ENOMEM;
   225	
   226		helper = kzalloc_obj(*helper, GFP_KERNEL_ACCOUNT);
 > 227		if (!helper)
   228			goto err_cth;
   229	
   230		nfcth->helper = helper;
   231	
   232		ret = nfnl_cthelper_parse_expect_policy(helper, tb[NFCTH_POLICY]);
   233		if (ret < 0)
   234			goto err_helper;
   235	
   236		nla_strscpy(helper->name,
   237			    tb[NFCTH_NAME], NF_CT_HELPER_NAME_LEN);
   238		size = ntohl(nla_get_be32(tb[NFCTH_PRIV_DATA_LEN]));
   239		if (size > sizeof_field(struct nf_conn_help, data)) {
   240			ret = -ENOMEM;
   241			goto err_helper;
   242		}
   243		helper->data_len = size;
   244	
   245		helper->flags |= NF_CT_HELPER_F_USERSPACE;
   246		memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple));
   247	
   248		helper->me = THIS_MODULE;
   249		helper->help = nfnl_userspace_cthelper;
   250		helper->from_nlattr = nfnl_cthelper_from_nlattr;
   251		helper->to_nlattr = nfnl_cthelper_to_nlattr;
   252	
   253		/* Default to queue number zero, this can be updated at any time. */
   254		if (tb[NFCTH_QUEUE_NUM])
   255			helper->queue_num = ntohl(nla_get_be32(tb[NFCTH_QUEUE_NUM]));
   256	
   257		if (tb[NFCTH_STATUS]) {
   258			int status = ntohl(nla_get_be32(tb[NFCTH_STATUS]));
   259	
   260			switch(status) {
   261			case NFCT_HELPER_STATUS_ENABLED:
   262				helper->flags |= NF_CT_HELPER_F_CONFIGURED;
   263				break;
   264			case NFCT_HELPER_STATUS_DISABLED:
   265				helper->flags &= ~NF_CT_HELPER_F_CONFIGURED;
   266				break;
   267			}
   268		}
   269	
   270		ret = __nf_conntrack_helper_register(helper);
   271		if (ret < 0)
   272			goto err_helper;
   273	
   274		list_add_tail(&nfcth->list, &nfnl_cthelper_list);
   275		return 0;
   276	err_helper:
   277		kfree(helper);
   278	err_cth:
   279		kfree(nfcth);
   280		return ret;
   281	}
   282	

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: net/netfilter/nfnetlink_cthelper.c:227:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is true

[Pablo Neira Ayuso]

On Thu, Jun 11, 2026 at 01:32:48AM +0200, kernel test robot wrote:
> vim +227 net/netfilter/nfnetlink_cthelper.c
> 
>    209	
>    210	static int
>    211	nfnl_cthelper_create(const struct nlattr * const tb[],
>    212			     struct nf_conntrack_tuple *tuple)
>    213	{
>    214		struct nf_conntrack_helper *helper;
>    215		struct nfnl_cthelper *nfcth;
>    216		unsigned int size;
>    217		int ret;
>    218	
>    219		if (!tb[NFCTH_TUPLE] || !tb[NFCTH_POLICY] || !tb[NFCTH_PRIV_DATA_LEN])
>    220			return -EINVAL;
>    221	
>    222		nfcth = kzalloc_obj(*nfcth, GFP_KERNEL_ACCOUNT);
>    223		if (nfcth == NULL)
>    224			return -ENOMEM;
>    225	
>    226		helper = kzalloc_obj(*helper, GFP_KERNEL_ACCOUNT);
>  > 227		if (!helper)
>    228			goto err_cth;

This seems to be running on an older patch.