diff options
| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2022-07-13 23:52:02 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-07-29 18:19:14 +0300 |
| commit | 97992e8feff33b3ae154a113ec398546bbacda80 (patch) | |
| tree | b4b9e2b23e1279dde084e9eec24246652e59b937 /net | |
| parent | 514d2254c7b8aa2d257f5ffc79f0d96be2d6bfda (diff) | |
| download | linux-97992e8feff33b3ae154a113ec398546bbacda80.tar.xz | |
tcp: Fix data-races around sysctl_tcp_min_snd_mss.
[ Upstream commit 78eb166cdefcc3221c8c7c1e2d514e91a2eb5014 ]
While reading sysctl_tcp_min_snd_mss, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.
Fixes: 5f3e2bf008c2 ("tcp: add tcp_min_snd_mss 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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/tcp_output.c | 3 | ||||
| -rw-r--r-- | net/ipv4/tcp_timer.c | 2 |
2 files changed, 3 insertions, 2 deletions
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 9f3eec8e7e4c..b0d49317b221 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -1720,7 +1720,8 @@ static inline int __tcp_mtu_to_mss(struct sock *sk, int pmtu) mss_now -= icsk->icsk_ext_hdr_len; /* Then reserve room for full set of TCP options and 8 bytes of data */ - mss_now = max(mss_now, sock_net(sk)->ipv4.sysctl_tcp_min_snd_mss); + mss_now = max(mss_now, + READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_min_snd_mss)); return mss_now; } diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c index 795716fd3761..953f36868369 100644 --- a/net/ipv4/tcp_timer.c +++ b/net/ipv4/tcp_timer.c @@ -173,7 +173,7 @@ static void tcp_mtu_probing(struct inet_connection_sock *icsk, struct sock *sk) 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, net->ipv4.sysctl_tcp_min_snd_mss); + mss = max(mss, READ_ONCE(net->ipv4.sysctl_tcp_min_snd_mss)); icsk->icsk_mtup.search_low = tcp_mss_to_mtu(sk, mss); } tcp_sync_mss(sk, icsk->icsk_pmtu_cookie); |