From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 64D8831352D for ; Sun, 13 Sep 2026 10:38:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789295894; cv=none; b=AX6ibEx6FZ0CW0d7ET6+b19OodqIClZOU76dpqgjSxZpCm3P0p8MSltv8gp+M6yFjDBQUE73sHMGyqsZkTZ89SOUW0qsg8n0oI6SrohRqbsMTjNBHswcBlrWOW96c0IKMPwWn3YVzz7czEelcu5lZra4biCND7uck8YHeyG5ihM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789295894; c=relaxed/simple; bh=QYBegstQV/V8Pxia/ybAXPtNqnifnh64lPMUhlgJa6w=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=d4xLx0jCiC1QcpUo79aLXN70Brev/PH/mMHUWBtepk75RCaiVpcwn5Zc3wp5UzVpmAJK0IDFE67LpoVtMXVuJ3Akl5uJIfBVPxN/p4Sad0YjdNsAi2QeSTs15OxP29sYTrknVjliDLSfp3Uad/zBvNmAZaB881XHBzrX7Uq7j/k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Nd/bT75B; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Nd/bT75B" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 029221F000FF; Sun, 13 Sep 2026 10:38:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789295891; bh=oj0GVCHKtvBKK+GA960Zqyhyiem9m2NEHMBBnnLIs5o=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Nd/bT75BZmnPquNGLp4CDHEtbXxE5ZT2eTspJO2OBA8fxFPR//qR2S/9aFoUPRcS9 hCYAVCqYiP5mGZmMfCTZwDKIJu92g786xvwxhwlLztWZAHKMYPEnFnGSjiFhC+HwpH RxN62qAKThohfzwRCYHMfV7kQYpQw6ZOKUpf/b2Jh9rl/OyOc9fNKTPPqgwh4yD4EM jwqME8Sw1aVx73DuuTmyJdngk+wx6j+xkK15oCzg5RIR6SXlzXji5Ees7fDlYwVhZx sUxTDmQNsuH9HWSWv+UWm4TE7k4ATF9dnVXaJ0NffUko0a46bZocDFYxEDGioZi4Mj z7z5TsldkgHHw== From: sashiko-bot@kernel.org Subject: Re: [PATCH mptcp-next v5 11/16] mptcp: add TCP_REPAIR sockopt support Reply-To: sashiko-reviews@lists.linux.dev To: "Geliang Tang" Cc: mptcp@lists.linux.dev In-Reply-To: <15960ae7fff68167e041400db0480e55950ea1c1.1789294365.git.tanggeliang@kylinos.cn> References: <15960ae7fff68167e041400db0480e55950ea1c1.1789294365.git.tanggeliang@kylinos.cn> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sun, 13 Sep 2026 10:38:10 +0000 Message-Id: <20260913103811.029221F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Thank you for your contribution! Sashiko AI review found 3 potential issue(= s) to consider: - [High] The check for repair mode in __mptcp_close() is placed after the f= astclose and shutdown sequences, breaking silent teardown. - [Medium] mptcp_setsockopt_sol_tcp() silently ignores error codes when set= ting TCP_REPAIR. - [Medium] TCP_REPAIR is missing from mptcp_getsockopt_sol_tcp(), causing g= etsockopt() to fail with -EOPNOTSUPP. -- commit 31eec098dfb51659558f320d2e2ec1abfdffb89c Author: Geliang Tang mptcp: add TCP_REPAIR sockopt support Add TCP_REPAIR socket option support for MPTCP, required for sockmap CRIU checkpoint/restore. When TCP_REPAIR is set on the first subflow, skip the normal connection handshake in mptcp_connect() and transition directly to TCP_ESTABLISHED. On close, skip the shutdown sequence and jump to cleanup when repair mode is active. > diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c > index c5be29767cb15..07132976016e3 100644 > --- a/net/mptcp/protocol.c > +++ b/net/mptcp/protocol.c > @@ -3560,6 +3560,11 @@ bool __mptcp_close(struct sock *sk, long timeout) > __mptcp_wr_shutdown(sk); > } > =20 > + if (msk->first && tcp_sk(msk->first)->repair) { > + mptcp_set_state(sk, TCP_CLOSE); > + goto cleanup; > + } > + [Severity: High] Does this check evaluate too late in the shutdown sequence? Since mptcp_do_fastclose() or __mptcp_wr_shutdown() can already be invoked just before this block, could closing an MPTCP socket in repair mode incorr= ectly leak RST or FIN packets to the network instead of being silently dismantled? > sk_stream_wait_close(sk, timeout); > =20 > cleanup: [ ... ] > diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c > index 922f6ae5c80cb..d2d1c9d1ed1d7 100644 > --- a/net/mptcp/sockopt.c > +++ b/net/mptcp/sockopt.c [ ... ] > @@ -918,6 +919,7 @@ static int mptcp_setsockopt_sol_tcp(struct mptcp_sock= *msk, int optname, > case TCP_CONGESTION: > return mptcp_setsockopt_sol_tcp_congestion(msk, optval, optlen); > case TCP_DEFER_ACCEPT: > + case TCP_REPAIR: > /* See tcp.c: TCP_DEFER_ACCEPT does not fail */ > mptcp_setsockopt_first_sf_only(msk, SOL_TCP, optname, optval, optlen); > return 0; [Severity: Medium] Since TCP_DEFER_ACCEPT does not fail, returning 0 unconditionally is correct for it. However, because setting TCP_REPAIR requires privileges, can the underlying tcp_setsockopt() fail and return an error like -EPERM? If so, does discarding the return value of mptcp_setsockopt_first_sf_only() cause these errors to be silently swallowed while returning 0 to the application? [Severity: Medium] Also, should TCP_REPAIR be added to mptcp_getsockopt_sol_tcp()? If it is omitted from the switch statement there, will applications queryin= g the repair state via getsockopt(SOL_TCP, TCP_REPAIR) incorrectly receive -EOPNOTSUPP? For example: net/mptcp/sockopt.c:mptcp_getsockopt_sol_tcp() { ... switch (optname) { case TCP_ULP: case TCP_CONGESTION: ... } --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/cover.1789294365.gi= t.tanggeliang@kylinos.cn?part=3D11