lkml.org 
[lkml]   [2022]   [Jul]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.4 24/87] tcp: Fix a data-race around sysctl_tcp_mtu_probe_floor.
Date
From: Kuniyuki Iwashima <kuniyu@amazon.com>

[ Upstream commit 8e92d4423615a5257d0d871fc067aa561f597deb ]

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

Fixes: c04b79b6cfd7 ("tcp: add new tcp_mtu_probe_floor sysctl")
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_timer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index 0460c5deee3f..c48aeaef3ec7 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -172,7 +172,7 @@ static void tcp_mtu_probing(struct inet_connection_sock *icsk, struct sock *sk)
} else {
mss = tcp_mtu_to_mss(sk, icsk->icsk_mtup.search_low) >> 1;
mss = min(READ_ONCE(net->ipv4.sysctl_tcp_base_mss), mss);
- mss = max(mss, net->ipv4.sysctl_tcp_mtu_probe_floor);
+ mss = max(mss, READ_ONCE(net->ipv4.sysctl_tcp_mtu_probe_floor));
mss = max(mss, READ_ONCE(net->ipv4.sysctl_tcp_min_snd_mss));
icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, mss);
}
--
2.35.1


\
 
 \ /
  Last update: 2022-07-27 18:40    [W:0.387 / U:0.240 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site