From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 A14E6C742B9 for ; Fri, 12 Jul 2019 12:22:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7AFEF208E4 for ; Fri, 12 Jul 2019 12:22:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562934138; bh=RGqaMnUl8fu5VGTAT/EWM2D/EJZuaOJplXwUWrI4ww0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=x93De8GLDnHSlCuEIe1G1LAheJvFj4p/QSC0wS+k9iJMgi5snbEwBqP0ppgqoxE0j kVQzh4CNKkQHof1bq5vSq/rr2iFdIQMZanaK7frmVDRINRr7V9K7PQaBwAkkkiQZJ8 0bdb4o+fKY1LLUX0poRpyi7V4q6YcEZbNjQUzAvk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727587AbfGLMVb (ORCPT ); Fri, 12 Jul 2019 08:21:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:55656 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727574AbfGLMV3 (ORCPT ); Fri, 12 Jul 2019 08:21:29 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 64E91216E3; Fri, 12 Jul 2019 12:21:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562934088; bh=RGqaMnUl8fu5VGTAT/EWM2D/EJZuaOJplXwUWrI4ww0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Q4kxAfcammzUKPyjruQB+SosiMiJ6mdLTTiWrc3n9/EiuU0Y6R8HP+bARvhwrDd/1 QfNn7IZ4+V+HtIDKOX+cWSvTmW1gYOO5L4iJMOSTCRb/tYhKCNhJnI8Q4BveU42wpo p4X8gyYgM/4kFvCv0H3r5TCrtE3MHdTDVfQqLM/k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, David Ahern , Toshiaki Makita , Daniel Borkmann , Sasha Levin Subject: [PATCH 4.19 40/91] bpf, devmap: Add missing RCU read lock on flush Date: Fri, 12 Jul 2019 14:18:43 +0200 Message-Id: <20190712121623.602025258@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190712121621.422224300@linuxfoundation.org> References: <20190712121621.422224300@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit 86723c8640633bee4b4588d3c7784ee7a0032f65 ] .ndo_xdp_xmit() assumes it is called under RCU. For example virtio_net uses RCU to detect it has setup the resources for tx. The assumption accidentally broke when introducing bulk queue in devmap. Fixes: 5d053f9da431 ("bpf: devmap prepare xdp frames for bulking") Reported-by: David Ahern Signed-off-by: Toshiaki Makita Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- kernel/bpf/devmap.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 357d456d57b9..fc500ca464d0 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -282,6 +282,7 @@ void __dev_map_flush(struct bpf_map *map) unsigned long *bitmap = this_cpu_ptr(dtab->flush_needed); u32 bit; + rcu_read_lock(); for_each_set_bit(bit, bitmap, map->max_entries) { struct bpf_dtab_netdev *dev = READ_ONCE(dtab->netdev_map[bit]); struct xdp_bulk_queue *bq; @@ -297,6 +298,7 @@ void __dev_map_flush(struct bpf_map *map) __clear_bit(bit, bitmap); } + rcu_read_unlock(); } /* rcu_read_lock (from syscall and BPF contexts) ensures that if a delete and/or @@ -389,6 +391,7 @@ static void dev_map_flush_old(struct bpf_dtab_netdev *dev) int cpu; + rcu_read_lock(); for_each_online_cpu(cpu) { bitmap = per_cpu_ptr(dev->dtab->flush_needed, cpu); __clear_bit(dev->bit, bitmap); @@ -396,6 +399,7 @@ static void dev_map_flush_old(struct bpf_dtab_netdev *dev) bq = per_cpu_ptr(dev->bulkq, cpu); bq_xmit_all(dev, bq, XDP_XMIT_FLUSH, false); } + rcu_read_unlock(); } } -- 2.20.1