2023-12-26 12:11:03

by Matthieu Baerts (NGI0)

[permalink] [raw]
Subject: [PATCH net 0/2] mptcp: new reviewer and prevent a warning

Patch 1 adds MPTCP long time contributor -- Geliang Tang -- as a new
reviewer for the project. Thanks!

Patch 2 prevents a warning when TCP Diag is used to close internal MPTCP
listener subflows. This is a correction for a patch introduced in v6.4
which was fixing an issue from v5.17.

Signed-off-by: Matthieu Baerts <[email protected]>
---
Matthieu Baerts (1):
MAINTAINERS: add Geliang as reviewer for MPTCP

Paolo Abeni (1):
mptcp: prevent tcp diag from closing listener subflows

MAINTAINERS | 1 +
net/mptcp/subflow.c | 13 +++++++++++++
2 files changed, 14 insertions(+)
---
base-commit: dff90e4a092b771354287fbe55e557467c9da620
change-id: 20231226-upstream-net-20231226-mptcp-prevent-warn-24f9494bb2a0

Best regards,
--
Matthieu Baerts <[email protected]>



2023-12-26 12:11:20

by Matthieu Baerts (NGI0)

[permalink] [raw]
Subject: [PATCH net 1/2] MAINTAINERS: add Geliang as reviewer for MPTCP

For a long time now, Geliang has contributed to a lot of code and
reviews related to MPTCP. So let's reflect that in the MAINTAINERS file.

This should also encourage patch submitters to add him to the CC list.

Acked-by: Geliang Tang <[email protected]>
Acked-by: Mat Martineau <[email protected]>
Signed-off-by: Matthieu Baerts <[email protected]>
---
MAINTAINERS | 1 +
1 file changed, 1 insertion(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 7cef2d2ef8d7..cc9e2dc4ad9a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15078,6 +15078,7 @@ K: \bmdo_
NETWORKING [MPTCP]
M: Matthieu Baerts <[email protected]>
M: Mat Martineau <[email protected]>
+R: Geliang Tang <[email protected]>
L: [email protected]
L: [email protected]
S: Maintained

--
2.43.0


2023-12-26 12:11:39

by Matthieu Baerts (NGI0)

[permalink] [raw]
Subject: [PATCH net 2/2] mptcp: prevent tcp diag from closing listener subflows

From: Paolo Abeni <[email protected]>

The MPTCP protocol does not expect that any other entity could change
the first subflow status when such socket is listening.
Unfortunately the TCP diag interface allows aborting any TCP socket,
including MPTCP listeners subflows. As reported by syzbot, that trigger
a WARN() and could lead to later bigger trouble.

The MPTCP protocol needs to do some MPTCP-level cleanup actions to
properly shutdown the listener. To keep the fix simple, prevent
entirely the diag interface from stopping such listeners.

We could refine the diag callback in a later, larger patch targeting
net-next.

Fixes: 57fc0f1ceaa4 ("mptcp: ensure listener is unhashed before updating the sk status")
Cc: [email protected]
Reported-by: <[email protected]>
Closes: https://lore.kernel.org/netdev/[email protected]/
Signed-off-by: Paolo Abeni <[email protected]>
Reviewed-by: Mat Martineau <[email protected]>
Signed-off-by: Matthieu Baerts <[email protected]>
---
net/mptcp/subflow.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 6d7684c35e93..852b3f4af000 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -1982,6 +1982,17 @@ static void tcp_release_cb_override(struct sock *ssk)
tcp_release_cb(ssk);
}

+static int tcp_abort_override(struct sock *ssk, int err)
+{
+ /* closing a listener subflow requires a great deal of care.
+ * keep it simple and just prevent such operation
+ */
+ if (inet_sk_state_load(ssk) == TCP_LISTEN)
+ return -EINVAL;
+
+ return tcp_abort(ssk, err);
+}
+
static struct tcp_ulp_ops subflow_ulp_ops __read_mostly = {
.name = "mptcp",
.owner = THIS_MODULE,
@@ -2026,6 +2037,7 @@ void __init mptcp_subflow_init(void)

tcp_prot_override = tcp_prot;
tcp_prot_override.release_cb = tcp_release_cb_override;
+ tcp_prot_override.diag_destroy = tcp_abort_override;

#if IS_ENABLED(CONFIG_MPTCP_IPV6)
/* In struct mptcp_subflow_request_sock, we assume the TCP request sock
@@ -2061,6 +2073,7 @@ void __init mptcp_subflow_init(void)

tcpv6_prot_override = tcpv6_prot;
tcpv6_prot_override.release_cb = tcp_release_cb_override;
+ tcpv6_prot_override.diag_destroy = tcp_abort_override;
#endif

mptcp_diag_subflow_init(&subflow_ulp_ops);

--
2.43.0


2024-01-03 00:20:46

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [PATCH net 0/2] mptcp: new reviewer and prevent a warning

Hello:

This series was applied to netdev/net.git (main)
by Jakub Kicinski <[email protected]>:

On Tue, 26 Dec 2023 13:10:16 +0100 you wrote:
> Patch 1 adds MPTCP long time contributor -- Geliang Tang -- as a new
> reviewer for the project. Thanks!
>
> Patch 2 prevents a warning when TCP Diag is used to close internal MPTCP
> listener subflows. This is a correction for a patch introduced in v6.4
> which was fixing an issue from v5.17.
>
> [...]

Here is the summary with links:
- [net,1/2] MAINTAINERS: add Geliang as reviewer for MPTCP
https://git.kernel.org/netdev/net/c/118ba479d02c
- [net,2/2] mptcp: prevent tcp diag from closing listener subflows
https://git.kernel.org/netdev/net/c/4c0288299fd0

You are awesome, thank you!
--
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