From: "Matthieu Baerts (NGI0)" matttbe@kernel.org
[ Upstream commit db75a16813aabae3b78c06b1b99f5e314c1f55d3 ]
Recently, some fallback have been initiated, while the connection was not supposed to fallback.
Add a safety check with a warning to detect when an wrong attempt to fallback is being done. This should help detecting any future issues quicker.
Acked-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org Link: https://patch.msgid.link/20250224-net-mptcp-misc-fixes-v1-3-f550f636b435@ker... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/mptcp/protocol.h | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 6026f0bcdea60..b92646ddbf077 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -870,6 +870,8 @@ static inline void __mptcp_do_fallback(struct mptcp_sock *msk) pr_debug("TCP fallback already done (msk=%p)\n", msk); return; } + if (WARN_ON_ONCE(!READ_ONCE(msk->allow_infinite_fallback))) + return; set_bit(MPTCP_FALLBACK_DONE, &msk->flags); }