--- zzzz-none-000/linux-4.9.218/net/netfilter/nf_conntrack_standalone.c	2020-04-02 15:20:41.000000000 +0000
+++ seale-7590ac-750/linux-4.9.218/net/netfilter/nf_conntrack_standalone.c	2022-11-30 09:46:20.000000000 +0000
@@ -17,6 +17,7 @@
 #include <linux/percpu.h>
 #include <linux/netdevice.h>
 #include <linux/security.h>
+#include <linux/inet.h>
 #include <net/net_namespace.h>
 #ifdef CONFIG_SYSCTL
 #include <linux/sysctl.h>
@@ -298,11 +299,67 @@
 			sizeof(struct ct_iter_state));
 }
 
+struct kill_request {
+	u16 family;
+	union nf_inet_addr addr;
+};
+
+static int kill_matching(struct nf_conn *i, void *data)
+{
+	struct kill_request *kr = data;
+	struct nf_conntrack_tuple *t1 = &i->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
+	struct nf_conntrack_tuple *t2 = &i->tuplehash[IP_CT_DIR_REPLY].tuple;
+
+	if (!kr->family)
+		return 1;
+
+	if (t1->src.l3num != kr->family)
+		return 0;
+
+	return (nf_inet_addr_cmp(&kr->addr, &t1->src.u3) ||
+		nf_inet_addr_cmp(&kr->addr, &t1->dst.u3) ||
+		nf_inet_addr_cmp(&kr->addr, &t2->src.u3) ||
+		nf_inet_addr_cmp(&kr->addr, &t2->dst.u3));
+}
+
+static ssize_t ct_file_write(struct file *file, const char __user *buf,
+			     size_t count, loff_t *ppos)
+{
+	struct seq_file *seq = file->private_data;
+	struct net *net = seq_file_net(seq);
+	struct kill_request kr = {};
+	char req[INET6_ADDRSTRLEN] = {};
+
+	if (count == 0)
+		return 0;
+
+	if (count >= INET6_ADDRSTRLEN)
+		count = INET6_ADDRSTRLEN - 1;
+
+	if (copy_from_user(req, buf, count))
+		return -EFAULT;
+
+	if (strnchr(req, count, ':')) {
+		kr.family = AF_INET6;
+		if (!in6_pton(req, count, (void *)&kr.addr, '\n', NULL))
+			return -EINVAL;
+	} else if (strnchr(req, count, '.')) {
+		kr.family = AF_INET;
+		if (!in4_pton(req, count, (void *)&kr.addr, '\n', NULL))
+			return -EINVAL;
+	}
+
+	nf_ct_iterate_cleanup(net, kill_matching, &kr, 0, 0);
+
+	return count;
+}
+
 static const struct file_operations ct_file_ops = {
-	.owner   = THIS_MODULE,
-	.open    = ct_open,
-	.read    = seq_read,
-	.llseek  = seq_lseek,
+	.owner = THIS_MODULE,
+	.open = ct_open,
+	.read = seq_read,
+	.write = ct_file_write,
+	.llseek = seq_lseek,
 	.release = seq_release_net,
 };
 
@@ -405,7 +462,7 @@
 	kuid_t root_uid;
 	kgid_t root_gid;
 
-	pde = proc_create("nf_conntrack", 0440, net->proc_net, &ct_file_ops);
+	pde = proc_create("nf_conntrack", 0660, net->proc_net, &ct_file_ops);
 	if (!pde)
 		goto out_nf_conntrack;