From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BEB3522E405; Mon, 3 Mar 2025 16:32:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741019527; cv=none; b=RJxEIe8//HAbdFCwzqh68iTdypUVmjHINoqyESDt+5EFl48xRghjSRis1bC+u71/fWE4FN9Klwr7Jez2jeYmycZZs7GgF3MSZPIVXbafYquHufcVp3IfJjkzzzqxMHbGvx+3V3+nfw5X4EdEV7km4YygvaznOhhTfF/2ifaDp8M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741019527; c=relaxed/simple; bh=4LlMWS7unNjrr4UO9L6/YFDaJLbN0Pbn3aVKgAkooS4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=F9WsRLn9xIjNj885TTk4K+vg4cAuyMqt75EO7SBGBz+hyDYNL9hG9yBkxjycHzye+hwkZBtHVd7/ZA32+41LA8AoBToF/4fzpAP1q9J0kwPbg0z7e9BGl1dQyaLgdX86DgynMaEu2DWG9UVPpv96TidfoUNP/LvySgPim959e+A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dCZk50QK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="dCZk50QK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68CDBC4CED6; Mon, 3 Mar 2025 16:32:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1741019527; bh=4LlMWS7unNjrr4UO9L6/YFDaJLbN0Pbn3aVKgAkooS4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dCZk50QKQklRygiHfqvmd9YQC+lJIg7B5J/OzLJuldIakCbTs9o5+a/4cDJLlpNHN 3rTe+pbI9EYFS6Z580FFwtk/3UVUIKWCodDzFnL6u+cc7DP6wHarUQu1sO3ivZtfe5 ysYabUuSk27ocgJBt7RejRhhXCk5oiDEjENiZttaEwiZYFDn0uXjEnQiKmg49dmw5F xqItIzcz/Xdv1Fcj24Cn5v1MiAhtgq/Pv7QK9uqdXk0V5O48fhcEaPYB2WK8JewW0e OCOABoFrJlL5Zvvs/j/cfrWMTWfcWxmdHJzdd6cFQw5OesCqjHtmQKOwINKJGgWzJi ebVfVVHC6BdHQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Matthieu Baerts (NGI0)" , Paolo Abeni , Jakub Kicinski , Sasha Levin , martineau@kernel.org, davem@davemloft.net, edumazet@google.com, netdev@vger.kernel.org, mptcp@lists.linux.dev Subject: [PATCH AUTOSEL 5.15 7/9] mptcp: safety check before fallback Date: Mon, 3 Mar 2025 11:31:50 -0500 Message-Id: <20250303163152.3764156-7-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250303163152.3764156-1-sashal@kernel.org> References: <20250303163152.3764156-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.178 Content-Transfer-Encoding: 8bit From: "Matthieu Baerts (NGI0)" [ 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 Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20250224-net-mptcp-misc-fixes-v1-3-f550f636b435@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- 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); } -- 2.39.5