From patchwork Thu Mar 4 21:32:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mat Martineau X-Patchwork-Id: 12116819 X-Patchwork-Delegate: kuba@kernel.org Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-21.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96E09C433E0 for ; Thu, 4 Mar 2021 21:36:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 529EB64FF1 for ; Thu, 4 Mar 2021 21:36:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239534AbhCDVfe (ORCPT ); Thu, 4 Mar 2021 16:35:34 -0500 Received: from mga12.intel.com ([192.55.52.136]:5221 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239480AbhCDVfa (ORCPT ); Thu, 4 Mar 2021 16:35:30 -0500 IronPort-SDR: kXaD578Y/2BWEwAg8QNhcdWp4nISC099BlMBA2TRlthfwkobUCjtiv8oaUtq3t9D/uEgki/4cy yf1ak48UOJBg== X-IronPort-AV: E=McAfee;i="6000,8403,9913"; a="166769414" X-IronPort-AV: E=Sophos;i="5.81,223,1610438400"; d="scan'208";a="166769414" Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Mar 2021 13:32:24 -0800 IronPort-SDR: lRSzzFIyx7PnzzMh9+e8zaWJBBwaIKqbatSHg/22N6hYnDgmXQjaO+f6kdCZGdL+tmFo3WNgPh 4buDsDCkjfTg== X-IronPort-AV: E=Sophos;i="5.81,223,1610438400"; d="scan'208";a="368329481" Received: from mjmartin-desk2.amr.corp.intel.com (HELO mjmartin-desk2.intel.com) ([10.254.105.71]) by orsmga003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Mar 2021 13:32:22 -0800 From: Mat Martineau To: netdev@vger.kernel.org Cc: Paolo Abeni , davem@davemloft.net, kuba@kernel.org, matthieu.baerts@tessares.net, mptcp@lists.01.org, Christoph Paasch , Mat Martineau Subject: [PATCH net 3/9] mptcp: fix memory accounting on allocation error Date: Thu, 4 Mar 2021 13:32:10 -0800 Message-Id: <20210304213216.205472-4-mathew.j.martineau@linux.intel.com> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210304213216.205472-1-mathew.j.martineau@linux.intel.com> References: <20210304213216.205472-1-mathew.j.martineau@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Paolo Abeni In case of memory pressure the MPTCP xmit path keeps at most a single skb in the tx cache, eventually freeing additional ones. The associated counter for forward memory is not update accordingly, and that causes the following splat: WARNING: CPU: 0 PID: 12 at net/core/stream.c:208 sk_stream_kill_queues+0x3ca/0x530 net/core/stream.c:208 Modules linked in: CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.11.0-rc2 #59 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 Workqueue: events mptcp_worker RIP: 0010:sk_stream_kill_queues+0x3ca/0x530 net/core/stream.c:208 Code: 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e 63 01 00 00 8b ab 00 01 00 00 e9 60 ff ff ff e8 2f 24 d3 fe 0f 0b eb 97 e8 26 24 d3 fe <0f> 0b eb a0 e8 1d 24 d3 fe 0f 0b e9 a5 fe ff ff 4c 89 e7 e8 0e d0 RSP: 0018:ffffc900000c7bc8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88810030ac40 RSI: ffffffff8262ca4a RDI: 0000000000000003 RBP: 0000000000000d00 R08: 0000000000000000 R09: ffffffff85095aa7 R10: ffffffff8262c9ea R11: 0000000000000001 R12: ffff888108908100 R13: ffffffff85095aa0 R14: ffffc900000c7c48 R15: 1ffff92000018f85 FS: 0000000000000000(0000) GS:ffff88811b200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa7444baef8 CR3: 0000000035ee9005 CR4: 0000000000170ef0 Call Trace: __mptcp_destroy_sock+0x4a7/0x6c0 net/mptcp/protocol.c:2547 mptcp_worker+0x7dd/0x1610 net/mptcp/protocol.c:2272 process_one_work+0x896/0x1170 kernel/workqueue.c:2275 worker_thread+0x605/0x1350 kernel/workqueue.c:2421 kthread+0x344/0x410 kernel/kthread.c:292 ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:296 At close time, as reported by syzkaller/Christoph. This change address the issue properly updating the fwd allocated memory counter in the error path. Reported-by: Christoph Paasch Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/136 Fixes: 724cfd2ee8aa ("mptcp: allocate TX skbs in msk context") Signed-off-by: Paolo Abeni Signed-off-by: Mat Martineau --- net/mptcp/protocol.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 7362a536cbc0..aa59101ffe54 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1189,6 +1189,7 @@ static bool mptcp_tx_cache_refill(struct sock *sk, int size, */ while (skbs->qlen > 1) { skb = __skb_dequeue_tail(skbs); + *total_ts -= skb->truesize; __kfree_skb(skb); } return skbs->qlen > 0;