[PATCH 5.15 129/201] tcp: Fix a data-race around sysctl_tcp_abort_on_overflow.

Greg Kroah-Hartman
2022-07-27T17:16:13Z

From: Kuniyuki Iwashima <kuniyu@amazon.com>

[ Upstream commit 2d17d9c7382327d00aeaea35af44e9b26d53206e ]

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

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: Sasha Levin <sashal@kernel.org>
---
net/ipv4/tcp_minisocks.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 39d8101e8f99..41368e77fbb8 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -789,7 +789,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
if (sk != req->rsk_listener)
__NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMIGRATEREQFAILURE);

- if (!sock_net(sk)->ipv4.sysctl_tcp_abort_on_overflow) {
+ if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_abort_on_overflow)) {
inet_rsk(req)->acked = 1;
return NULL;
}
--
2.35.1