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 774B0155333; Wed, 3 Sep 2025 22:23:33 +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=1756938213; cv=none; b=eUeKkdIEjDso4uS0UxBJXi7C8oTxW9KGvJw16Ea0Vjpt8IMrxrfXE96cMG8bRJ0cghniLlpn/XAy6aLBQWYluwsPQtTD3hjFMP5yLhLHZPw/Ghj5wpy4Zelvl3EoTjp+VKZX4oH5XPVao00+GnhOO9jpOdpUaeHFq8UCzf3bTD4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756938213; c=relaxed/simple; bh=jrkblcjGxSiHwQsBa5HDYIOJoo+Comb6dZxIOGsodJA=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Xu9VJwAdN0m5eJKzDBOXBWxS23XeTZgNjHVGornj6S4zqj/y9EHnbTSkWXMTlOqpGrLCTeatTnvtuYPI8qRhjJ+jutwyWK74Qdz79bFUn5I+okmnNF0kpzPmIUbCsZkIcTT9XogpMq4Lylyp0N1RBf//7++NtGHTxFbw9i4RjMw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Yw4W1lVd; 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="Yw4W1lVd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52122C4CEE7; Wed, 3 Sep 2025 22:23:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1756938213; bh=jrkblcjGxSiHwQsBa5HDYIOJoo+Comb6dZxIOGsodJA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Yw4W1lVdTw2HhsxWgMLW0uUb8zYiFaLgc8aN24/kXXkMu23QXcNagj1dOsAidxwaF qTlvhFhgRdidp9L3nAfegzmk2PIrP9122rriJFGB5WKpQjsdMB8dI2zAiI9UvyObzP ihCyPZfIP2Py7t4z3Ci/0MDsSuYIVg8pty36Pe0dYhna6/KmyS47cUODUsYh9+EwAk pGifHX9/Vn+fB2PaWcVApaTF8p2bYG5ZdD3wrW/PC34PXrszHd79+XIGxi//NqL/fC C2v9tf3sxs1Hce9shI9EbrJe3P5wQQv6YEtlZ6Jyjs6ZShrK6KEXVFziz8XIYfjKa0 zx0i+dqKi1u+w== Date: Wed, 3 Sep 2025 15:23:31 -0700 From: Jakub Kicinski To: Dmitry Safonov Cc: Dmitry Safonov via B4 Relay , Eric Dumazet , Neal Cardwell , Kuniyuki Iwashima , "David S. Miller" , David Ahern , Paolo Abeni , Simon Horman , Bob Gilligan , Salam Noureddine , Dmitry Safonov <0x7f454c46@gmail.com>, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH net-next v3 2/2] tcp: Free TCP-AO/TCP-MD5 info/keys without RCU Message-ID: <20250903152331.2e31b3cf@kernel.org> In-Reply-To: References: <20250830-b4-tcp-ao-md5-rst-finwait2-v3-0-9002fec37444@arista.com> <20250830-b4-tcp-ao-md5-rst-finwait2-v3-2-9002fec37444@arista.com> <20250902160858.0b237301@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Wed, 3 Sep 2025 18:41:39 +0100 Dmitry Safonov wrote: > > On Sat, 30 Aug 2025 05:31:47 +0100 Dmitry Safonov via B4 Relay wrote: > > > Now that the destruction of info/keys is delayed until the socket > > > destructor, it's safe to use kfree() without an RCU callback. > > > As either socket was yet in TCP_CLOSE state or the socket refcounter is > > > zero and no one can discover it anymore, it's safe to release memory > > > straight away. > > > Similar thing was possible for twsk already. > > > > After this patch the rcu members of struct tcp_ao* seem to no longer > > be used? > > Right. I'll remove tcp_ao_info::rcu in v4. > For tcp_ao_key it's needed for the regular key rotation, as well as > for tcp_md5sig_key. Hm, maybe I missed something. I did a test allmodconfig build yesterday and while the md5sig_key rcu was still needed, removing the ao_key didn't cause issues. But it was just a quick test I didn't even config kconfig is sane.