From: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
To: "David S . Miller" <davem@davemloft.net>,
Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
"Jakub Kicinski" <kuba@kernel.org>
Cc: Willem de Bruijn <willemb@google.com>,
Eric Dumazet <edumazet@google.com>,
Craig Gallek <kraig@google.com>, Paolo Abeni <pabeni@redhat.com>,
<netdev@vger.kernel.org>, Kuniyuki Iwashima <kuniyu@amazon.co.jp>,
"Kuniyuki Iwashima" <kuni1840@gmail.com>,
Benjamin Herrenschmidt <benh@amazon.com>,
<osa-contribution-log@amazon.com>
Subject: [PATCH net 1/2] udp: Copy has_conns in reuseport_grow().
Date: Tue, 21 Jul 2020 15:15:30 +0900 [thread overview]
Message-ID: <20200721061531.94236-2-kuniyu@amazon.co.jp> (raw)
In-Reply-To: <20200721061531.94236-1-kuniyu@amazon.co.jp>
If an unconnected socket in a UDP reuseport group connect()s, has_conns is
set to 1. Then, when a packet is received, udp[46]_lib_lookup2() scans all
sockets in udp_hslot looking for the connected socket with the highest
score.
However, when the number of sockets bound to the port exceeds max_socks,
reuseport_grow() resets has_conns to 0. It can cause udp[46]_lib_lookup2()
to return without scanning all sockets, resulting in that packets sent to
connected sockets may be distributed to unconnected sockets.
Therefore, reuseport_grow() should copy has_conns.
Fixes: acdcecc61285 ("udp: correct reuseport selection with connected sockets")
CC: Willem de Bruijn <willemb@google.com>
Reviewed-by: Benjamin Herrenschmidt <benh@amazon.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
---
net/core/sock_reuseport.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/core/sock_reuseport.c b/net/core/sock_reuseport.c
index adcb3aea576d..bbdd3c7b6cb5 100644
--- a/net/core/sock_reuseport.c
+++ b/net/core/sock_reuseport.c
@@ -101,6 +101,7 @@ static struct sock_reuseport *reuseport_grow(struct sock_reuseport *reuse)
more_reuse->prog = reuse->prog;
more_reuse->reuseport_id = reuse->reuseport_id;
more_reuse->bind_inany = reuse->bind_inany;
+ more_reuse->has_conns = reuse->has_conns;
memcpy(more_reuse->socks, reuse->socks,
reuse->num_socks * sizeof(struct sock *));
--
2.17.2 (Apple Git-113)
next prev parent reply other threads:[~2020-07-21 6:16 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-21 6:15 [PATCH net 0/2] udp: Fix reuseport selection with connected sockets Kuniyuki Iwashima
2020-07-21 6:15 ` Kuniyuki Iwashima [this message]
2020-07-21 12:25 ` [PATCH net 1/2] udp: Copy has_conns in reuseport_grow() Willem de Bruijn
2020-07-21 6:15 ` [PATCH net 2/2] udp: Improve load balancing for SO_REUSEPORT Kuniyuki Iwashima
2020-07-21 12:33 ` Willem de Bruijn
2020-07-21 22:32 ` [PATCH net 0/2] udp: Fix reuseport selection with connected sockets David Miller
2020-07-22 4:28 ` Kuniyuki Iwashima
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