From: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
[ Upstream commit a11e5b3e7a59fde1a90b0eaeaa82320495cf8cae ]
While reading sysctl_tcp_max_reordering, it can be changed
concurrently. Thus, we need to add READ_ONCE() to its readers.
Fixes: dca145ffaa8d ("tcp: allow for bigger reordering level")
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/ipv4/tcp_input.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index f200dd654e05..19b186a4a8e8 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -1051,7 +1051,7 @@ static void tcp_check_sack_reordering(struct sock *sk, const u32 low_seq,
tp->undo_marker ? tp->undo_retrans : 0);
#endif
tp->reordering = min_t(u32, (metric + mss - 1) / mss,
- sock_net(sk)->ipv4.sysctl_tcp_max_reordering);
+ READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_max_reordering));
}
/* This exciting event is worth to be remembered. 8) */
@@ -2030,7 +2030,7 @@ static void tcp_check_reno_reordering(struct sock *sk, const int addend)
return;
tp->reordering = min_t(u32, tp->packets_out + addend,
- sock_net(sk)->ipv4.sysctl_tcp_max_reordering);
+ READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_max_reordering));
tp->reord_seen++;
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRENOREORDER);
}
--
2.35.1
