Commit 1e306ec4 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

tcp: fix possible sk_priority leak in tcp_v4_send_reset() 



When tcp_v4_send_reset() is called with @sk == NULL,
we do not change ctl_sk->sk_priority, which could have been
set from a prior invocation.

Change tcp_v4_send_reset() to set sk_priority and sk_mark
fields before calling ip_send_unicast_reply().

This means tcp_v4_send_reset() and tcp_v4_send_ack()
no longer have to clear ctl_sk->sk_mark after
their call to ip_send_unicast_reply().

Fixes: f6c0f5d2 ("tcp: honor SO_PRIORITY in TIME_WAIT state")
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Antoine Tenart <atenart@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6d4486ef

net/ipv4/tcp_ipv4.c

+3 −2
Original line number Diff line number Diff line
@@ -829,6 +829,9 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) 
				   inet_twsk(sk)->tw_priority : sk->sk_priority;

		transmit_time = tcp_transmit_time(sk);

		xfrm_sk_clone_policy(ctl_sk, sk);

	} else {

		ctl_sk->sk_mark = 0;

		ctl_sk->sk_priority = 0;

	}

	ip_send_unicast_reply(ctl_sk,

			      skb, &TCP_SKB_CB(skb)->header.h4.opt,
@@ -836,7 +839,6 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb) 
			      &arg, arg.iov[0].iov_len,

			      transmit_time);



	ctl_sk->sk_mark = 0;

	xfrm_sk_free_policy(ctl_sk);

	sock_net_set(ctl_sk, &init_net);

	__TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
@@ -935,7 +937,6 @@ static void tcp_v4_send_ack(const struct sock *sk, 
			      &arg, arg.iov[0].iov_len,

			      transmit_time);



	ctl_sk->sk_mark = 0;

	sock_net_set(ctl_sk, &init_net);

	__TCP_INC_STATS(net, TCP_MIB_OUTSEGS);

	local_bh_enable();