Commit 59bf6c65 authored by Kuniyuki Iwashima's avatar Kuniyuki Iwashima Committed by David S. Miller
Browse files

tcp: Fix data-races around sk_pacing_rate. 



While reading sysctl_tcp_pacing_(ss|ca)_ratio, they can be changed
concurrently.  Thus, we need to add READ_ONCE() to their readers.

Fixes: 43e122b0 ("tcp: refine pacing rate determination")
Signed-off-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3e7d18b9

net/ipv4/tcp_input.c

+2 −2
Original line number Diff line number Diff line
@@ -910,9 +910,9 @@ static void tcp_update_pacing_rate(struct sock *sk) 
	 *	 end of slow start and should slow down.

	 */

	if (tcp_snd_cwnd(tp) < tp->snd_ssthresh / 2)

		rate *= sock_net(sk)->ipv4.sysctl_tcp_pacing_ss_ratio;

		rate *= READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_pacing_ss_ratio);

	else

		rate *= sock_net(sk)->ipv4.sysctl_tcp_pacing_ca_ratio;

		rate *= READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_pacing_ca_ratio);



	rate *= max(tcp_snd_cwnd(tp), tp->packets_out);