This is a note to let you know that I've just added the patch titled
tcp: Fix data-races around sk_pacing_rate.
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tcp-fix-data-races-around-sk_pacing_rate.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 4f19f4db66e4df97f9b37509bbe6497cffa150c7
Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Date: Fri Jul 22 11:21:59 2022 -0700
tcp: Fix data-races around sk_pacing_rate.
[ Upstream commit 59bf6c65a09fff74215517aecffbbdcd67df76e3 ]
While reading sysctl_tcp_pacing_(ss|ca)_ratio, they can be changed
concurrently. Thus, we need to add READ_ONCE() to their readers.
Fixes: 43e122b014c9 ("tcp: refine pacing rate determination")
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 018be3f346e6..566745f527fe 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -902,9 +902,9 @@ 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);
