Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ae0f7d5f authored by David Woodhouse's avatar David Woodhouse Committed by David S. Miller
Browse files

[IPV6]: Avoid calling ip6_xmit() with NULL sk 



The ip6_xmit() function now assumes that its sk argument is non-NULL,
which isn't currently true when TCPv6 code is sending RST or ACK
packets. This fixes that code to use a socket of its own for sending
such packets, as TCPv4 does. (Thanks Andi for the pointer).

Signed-off-by: default avatarDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a7768097

net/ipv6/tcp_ipv6.c

+18 −2
Original line number Diff line number Diff line
@@ -67,6 +67,9 @@ 
#include <linux/proc_fs.h>

#include <linux/seq_file.h>



/* Socket used for sending RSTs and ACKs */

static struct socket *tcp6_socket;



static void	tcp_v6_send_reset(struct sk_buff *skb);

static void	tcp_v6_reqsk_send_ack(struct sk_buff *skb, struct request_sock *req);

static void	tcp_v6_send_check(struct sock *sk, int len,
@@ -611,7 +614,7 @@ static void tcp_v6_send_reset(struct sk_buff *skb) 
	if (!ip6_dst_lookup(NULL, &buff->dst, &fl)) {



		if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {

			ip6_xmit(NULL, buff, &fl, NULL, 0);

			ip6_xmit(tcp6_socket->sk, buff, &fl, NULL, 0);

			TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);

			TCP_INC_STATS_BH(TCP_MIB_OUTRSTS);

			return;
@@ -675,7 +678,7 @@ static void tcp_v6_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 


	if (!ip6_dst_lookup(NULL, &buff->dst, &fl)) {

		if (xfrm_lookup(&buff->dst, &fl, NULL, 0) >= 0) {

			ip6_xmit(NULL, buff, &fl, NULL, 0);

			ip6_xmit(tcp6_socket->sk, buff, &fl, NULL, 0);

			TCP_INC_STATS_BH(TCP_MIB_OUTSEGS);

			return;

		}
@@ -1600,8 +1603,21 @@ static struct inet_protosw tcpv6_protosw = { 


void __init tcpv6_init(void)

{

	int err;



	/* register inet6 protocol */

	if (inet6_add_protocol(&tcpv6_protocol, IPPROTO_TCP) < 0)

		printk(KERN_ERR "tcpv6_init: Could not register protocol\n");

	inet6_register_protosw(&tcpv6_protosw);



	err = sock_create_kern(PF_INET6, SOCK_RAW, IPPROTO_TCP, &tcp6_socket);

	if (err < 0)

		panic("Failed to create the TCPv6 control socket.\n");

	tcp6_socket->sk->sk_allocation = GFP_ATOMIC;



	/* Unhash it so that IP input processing does not even

	 * see it, we do not wish this socket to see incoming

	 * packets.

	 */

	tcp6_socket->sk->sk_prot->unhash(tcp6_socket->sk);

}