This is a note to let you know that I've just added the patch titled
tcp: Fix data-races around sysctl_tcp_moderate_rcvbuf.
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-sysctl_tcp_moderate_rcvbuf.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 b3a4a46c8114c2565fd8b6758f66f760b12588da
Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Date: Wed Jul 20 09:50:18 2022 -0700
tcp: Fix data-races around sysctl_tcp_moderate_rcvbuf.
[ Upstream commit 780476488844e070580bfc9e3bc7832ec1cea883 ]
While reading sysctl_tcp_moderate_rcvbuf, it can be changed
concurrently. Thus, we need to add READ_ONCE() to its readers.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
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 b9fd51826aea..426f8fe02850 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -716,7 +716,7 @@ void tcp_rcv_space_adjust(struct sock *sk)
* <prev RTT . ><current RTT .. ><next RTT .... >
*/
- if (sock_net(sk)->ipv4.sysctl_tcp_moderate_rcvbuf &&
+ if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_moderate_rcvbuf) &&
!(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) {
int rcvmem, rcvbuf;
u64 rcvwin, grow;
diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index d6def23b8cba..01ede89e3c46 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -1881,7 +1881,7 @@ static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied)
if (msk->rcvq_space.copied <= msk->rcvq_space.space)
goto new_measure;
- if (sock_net(sk)->ipv4.sysctl_tcp_moderate_rcvbuf &&
+ if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_moderate_rcvbuf) &&
!(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) {
int rcvmem, rcvbuf;
u64 rcvwin, grow;
