Re: [PATCH net v2] ipvs: fix MTU check for GSO packets in tunnel mode

kernel test robot <[email protected]> Tue, 7 Apr 2026 18:38:32 +0800
Newsgroups org.kernel.vger.lvs-devel,dev.linux.lists.llvm,dev.linux.lists.oe-kbuild-all,org.kernel.vger.linux-kernel,org.kernel.vger.netdev,org.kernel.vger.netfilter-devel
Message-ID <[email protected]>
Hi Yingnan,

kernel test robot noticed the following build errors:

[auto build test ERROR on net/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Yingnan-Zhang/ipvs-fix-MTU-check-for-GSO-packets-in-tunnel-mode/20260407-141549
base:   net/main
patch link:    https://lore.kernel.org/r/tencent_CA2C1C219C99D315086BE55E8654AF7E6009%40qq.com
patch subject: [PATCH net v2] ipvs: fix MTU check for GSO packets in tunnel mode
config: x86_64-rhel-9.4-rust (https://download.01.org/0day-ci/archive/20260407/[email protected]/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
rustc: rustc 1.88.0 (6b00bc388 2025-06-23)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260407/[email protected]/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 <[email protected]>
| Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/

All error/warnings (new ones prefixed by >>):

>> net/netfilter/ipvs/ip_vs_xmit.c:115:2: warning: non-void function does not return a value in all control paths [-Wreturn-type]
     115 |         } else if (skb->len > mtu &&
         |         ^
>> net/netfilter/ipvs/ip_vs_xmit.c:115:4: error: expected identifier or '('
     115 |         } else if (skb->len > mtu &&
         |           ^
   net/netfilter/ipvs/ip_vs_xmit.c:119:2: error: expected identifier or '('
     119 |         return false;
         |         ^
>> net/netfilter/ipvs/ip_vs_xmit.c:120:1: error: extraneous closing brace ('}')
     120 | }
         | ^
   1 warning and 3 errors generated.


vim +115 net/netfilter/ipvs/ip_vs_xmit.c

   104	
   105	static inline bool
   106	__mtu_check_toobig_v6(const struct sk_buff *skb, u32 mtu)
   107	{
   108		if (IP6CB(skb)->frag_max_size) {
   109			/* frag_max_size tell us that, this packet have been
   110			 * defragmented by netfilter IPv6 conntrack module.
   111			 */
   112			if (IP6CB(skb)->frag_max_size > mtu)
   113				return true; /* largest fragment violate MTU */
   114		}
 > 115		} else if (skb->len > mtu &&
   116			   !(skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))) {
   117			return true; /* Packet size violate MTU size */
   118		}
   119		return false;
 > 120	}
   121	

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