From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) (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 95AE2370 for ; Tue, 28 Jun 2022 01:02:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1656378172; x=1687914172; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=i6wITeGD2ci5ZfC2XCyuFVON6e/8N77vyd9vkqBeJqU=; b=GW4alMs//NbAeL6m715SgnHunyIf+k64/JLvtDTeEfYvkLoDGnEzU/C1 0TkTEqR/w39mRrF7A52L+NyOPK5kyB8utAsh9jDa3JrHzSLcSkNheIdBf yr6e+O8ImmIEyTFqARizVEWEQu6uhgdW4erWzGayOqAmg/z10pKw4viXa q4ltUR81u+/Yo9TGmQoY9IcSv2AWiy9XRAskU7plipeJsklcr72Oguz5g /zRYtkE5JcErzG67f9FMQ+qBfBSUejYnK6ExAthmoyLJ9Lw7yA003CZrk Farios7sazCIT0t0xPXBflLO+HLkuo+3n2tUnoyjB0KIE4dYxF5fN6cbC g==; X-IronPort-AV: E=McAfee;i="6400,9594,10391"; a="270347716" X-IronPort-AV: E=Sophos;i="5.92,227,1650956400"; d="scan'208";a="270347716" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2022 18:02:50 -0700 X-IronPort-AV: E=Sophos;i="5.92,227,1650956400"; d="scan'208";a="692867381" Received: from cgarner-mobl1.amr.corp.intel.com (HELO mjmartin-desk2.intel.com) ([10.251.0.217]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 27 Jun 2022 18:02:50 -0700 From: Mat Martineau To: netdev@vger.kernel.org Cc: Paolo Abeni , davem@davemloft.net, kuba@kernel.org, edumazet@google.com, fw@strlen.de, geliang.tang@suse.com, matthieu.baerts@tessares.net, mptcp@lists.linux.dev, Mat Martineau Subject: [PATCH net 4/9] mptcp: fix shutdown vs fallback race Date: Mon, 27 Jun 2022 18:02:38 -0700 Message-Id: <20220628010243.166605-5-mathew.j.martineau@linux.intel.com> X-Mailer: git-send-email 2.37.0 In-Reply-To: <20220628010243.166605-1-mathew.j.martineau@linux.intel.com> References: <20220628010243.166605-1-mathew.j.martineau@linux.intel.com> Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Paolo Abeni If the MPTCP socket shutdown happens before a fallback to TCP, and all the pending data have been already spooled, we never close the TCP connection. Address the issue explicitly checking for critical condition at fallback time. Fixes: 1e39e5a32ad7 ("mptcp: infinite mapping sending") Fixes: 0348c690ed37 ("mptcp: add the fallback check") Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau --- net/mptcp/options.c | 2 +- net/mptcp/protocol.c | 2 +- net/mptcp/protocol.h | 19 ++++++++++++++++--- net/mptcp/subflow.c | 2 +- 4 files changed, 19 insertions(+), 6 deletions(-) diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 2a6351d55a7d..aead331866a0 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -967,7 +967,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, goto reset; subflow->mp_capable = 0; pr_fallback(msk); - __mptcp_do_fallback(msk); + mptcp_do_fallback(ssk); return false; } diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index e6fcb61443dd..e63bc2bb7fff 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1245,7 +1245,7 @@ static void mptcp_update_infinite_map(struct mptcp_sock *msk, MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPTX); mptcp_subflow_ctx(ssk)->send_infinite_map = 0; pr_fallback(msk); - __mptcp_do_fallback(msk); + mptcp_do_fallback(ssk); } static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 1d2d71711872..9860179bfd5e 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -927,12 +927,25 @@ static inline void __mptcp_do_fallback(struct mptcp_sock *msk) set_bit(MPTCP_FALLBACK_DONE, &msk->flags); } -static inline void mptcp_do_fallback(struct sock *sk) +static inline void mptcp_do_fallback(struct sock *ssk) { - struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); - struct mptcp_sock *msk = mptcp_sk(subflow->conn); + struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); + struct sock *sk = subflow->conn; + struct mptcp_sock *msk; + msk = mptcp_sk(sk); __mptcp_do_fallback(msk); + if (READ_ONCE(msk->snd_data_fin_enable) && !(ssk->sk_shutdown & SEND_SHUTDOWN)) { + gfp_t saved_allocation = ssk->sk_allocation; + + /* we are in a atomic (BH) scope, override ssk default for data + * fin allocation + */ + ssk->sk_allocation = GFP_ATOMIC; + ssk->sk_shutdown |= SEND_SHUTDOWN; + tcp_shutdown(ssk, SEND_SHUTDOWN); + ssk->sk_allocation = saved_allocation; + } } #define pr_fallback(a) pr_debug("%s:fallback to TCP (msk=%p)", __func__, a) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 8dfea6a8a82f..b34b96fb742f 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -1279,7 +1279,7 @@ static bool subflow_check_data_avail(struct sock *ssk) return false; } - __mptcp_do_fallback(msk); + mptcp_do_fallback(ssk); } skb = skb_peek(&ssk->sk_receive_queue); -- 2.37.0