!1682 netfilter: nft_set_pipapo: fix improper element removal

Merge Pull Request from: @ci-robot 
 
PR sync from: Lu Wei <luwei32@huawei.com>
https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/XHWCN4LVCI4W4ZNP4NXSYHBEYGDNGBUG/ 
 
https://gitee.com/src-openeuler/kernel/issues/I7P3TK 
 
Link:https://gitee.com/openeuler/kernel/pulls/1682 

Reviewed-by: Yue Haibing <yuehaibing@huawei.com> 
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com> 

net/netfilter/nft_set_pipapo.c

@@ -1904,7 +1904,11 @@ static void nft_pipapo_remove(const struct net *net, const struct nft_set *set,
 		int i, start, rules_fx;
 
 		match_start = data;
-		match_end = (const u8 *)nft_set_ext_key_end(&e->ext)->data;
+
+		if (nft_set_ext_exists(&e->ext, NFT_SET_EXT_KEY_END))
+			match_end = (const u8 *)nft_set_ext_key_end(&e->ext)->data;
+		else
+			match_end = data;
 
 		start = first_rule;
 		rules_fx = rules_f0;