Re: [PATCH v3 2/2] net: sched: act_ife: initialize struct tc_ife to fix KMSAN kernel-infoleak

Hi Ranganath,

kernel test robot noticed the following build errors:

[auto build test ERROR on net-next/main]
[also build test ERROR on net/main linus/master v6.18-rc4 next-20251107]
[cannot apply to horms-ipvs/master]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Ranganath-V-N/net-sched-act_connmark-initialize-struct-tc_ife-to-fix-kernel-leak/20251107-035911
base:   net-next/main
patch link:    https://lore.kernel.org/r/20251106195635.2438-3-vnranganath.20%40gmail.com
patch subject: [PATCH v3 2/2] net: sched: act_ife: initialize struct tc_ife to fix KMSAN kernel-infoleak
config: s390-randconfig-r073-20251108 (https://download.01.org/0day-ci/archive/20251108/202511080954.ZMCEd0sG-lkp@intel.com/config)
compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project d78e0ded5215824a63ac04fb87effd9eacf875eb)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251108/202511080954.ZMCEd0sG-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 [off-list ref]
| Closes: https://lore.kernel.org/oe-kbuild-all/202511080954.ZMCEd0sG-lkp@intel.com/ (local)

All errors (new ones prefixed by >>):

quoted

net/sched/act_ife.c:652:2: error: call to undeclared library function 'index' with type 'char *(const char *, int)'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]

     652 |         index = ife->tcf_index;
         |         ^
   net/sched/act_ife.c:652:2: note: include the header <strings.h> or explicitly provide a declaration for 'index'

quoted

net/sched/act_ife.c:652:8: error: non-object type 'char *(const char *, int)' is not assignable

     652 |         index = ife->tcf_index;
         |         ~~~~~ ^

quoted

net/sched/act_ife.c:653:2: error: use of undeclared identifier 'refcnt'

     653 |         refcnt = refcount_read(&ife->tcf_refcnt) - ref;
         |         ^~~~~~

quoted

net/sched/act_ife.c:654:2: error: use of undeclared identifier 'bindcnt'

     654 |         bindcnt = atomic_read(&ife->tcf_bindcnt) - bind;
         |         ^~~~~~~
   4 errors generated.


vim +652 net/sched/act_ife.c

   640	
   641	static int tcf_ife_dump(struct sk_buff *skb, struct tc_action *a, int bind,
   642				int ref)
   643	{
   644		unsigned char *b = skb_tail_pointer(skb);
   645		struct tcf_ife_info *ife = to_ife(a);
   646		struct tcf_ife_params *p;
   647		struct tc_ife opt;
   648		struct tcf_t t;
   649	
   650		memset(&opt, 0, sizeof(opt));
   651	
 > 652		index = ife->tcf_index;
 > 653		refcnt = refcount_read(&ife->tcf_refcnt) - ref;
 > 654		bindcnt = atomic_read(&ife->tcf_bindcnt) - bind;
   655	
   656		spin_lock_bh(&ife->tcf_lock);
   657		opt.action = ife->tcf_action;
   658		p = rcu_dereference_protected(ife->params,
   659					      lockdep_is_held(&ife->tcf_lock));
   660		opt.flags = p->flags;
   661	
   662		if (nla_put(skb, TCA_IFE_PARMS, sizeof(opt), &opt))
   663			goto nla_put_failure;
   664	
   665		tcf_tm_dump(&t, &ife->tcf_tm);
   666		if (nla_put_64bit(skb, TCA_IFE_TM, sizeof(t), &t, TCA_IFE_PAD))
   667			goto nla_put_failure;
   668	
   669		if (!is_zero_ether_addr(p->eth_dst)) {
   670			if (nla_put(skb, TCA_IFE_DMAC, ETH_ALEN, p->eth_dst))
   671				goto nla_put_failure;
   672		}
   673	
   674		if (!is_zero_ether_addr(p->eth_src)) {
   675			if (nla_put(skb, TCA_IFE_SMAC, ETH_ALEN, p->eth_src))
   676				goto nla_put_failure;
   677		}
   678	
   679		if (nla_put(skb, TCA_IFE_TYPE, 2, &p->eth_type))
   680			goto nla_put_failure;
   681	
   682		if (dump_metalist(skb, ife)) {
   683			/*ignore failure to dump metalist */
   684			pr_info("Failed to dump metalist\n");
   685		}
   686	
   687		spin_unlock_bh(&ife->tcf_lock);
   688		return skb->len;
   689	
   690	nla_put_failure:
   691		spin_unlock_bh(&ife->tcf_lock);
   692		nlmsg_trim(skb, b);
   693		return -1;
   694	}
   695	

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