Commit 78047648 authored Jul 20, 2022 by Kuniyuki Iwashima Committed by David S. Miller Jul 22, 2022

tcp: Fix data-races around sysctl_tcp_moderate_rcvbuf.



While reading sysctl_tcp_moderate_rcvbuf, it can be changed
concurrently.  Thus, we need to add READ_ONCE() to its readers.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent ab1ba21b

net/ipv4/tcp_input.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -724,7 +724,7 @@ 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;

net/mptcp/protocol.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1908,7 +1908,7 @@ 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;