From: Kuniyuki Iwashima kuniyu@amazon.com
commit 780476488844e070580bfc9e3bc7832ec1cea883 upstream.
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@amazon.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/tcp_input.c | 2 +- net/mptcp/protocol.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)
--- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -724,7 +724,7 @@ void tcp_rcv_space_adjust(struct sock *s * <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; --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1882,7 +1882,7 @@ static void mptcp_rcv_space_adjust(struc 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;