From patchwork Sun Oct 20 15:46:10 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tom Rix X-Patchwork-Id: 1180030 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="bq/XcSfk"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 46x3zC3c35z9sPL for ; Mon, 21 Oct 2019 02:46:31 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726495AbfJTPqZ (ORCPT ); Sun, 20 Oct 2019 11:46:25 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:49287 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726467AbfJTPqZ (ORCPT ); Sun, 20 Oct 2019 11:46:25 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1571586383; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=NYB5YLU3InOkXCV2AcZVtukurd9BwBDSqfTnbkNJyC8=; b=bq/XcSfkXbhphf9CLs5z6dK3sKoTap6FyvaWccsshUz0wmjjMZ64ssyLZw8ZbEomNiKZAX Jkn6k4RzARE/B/zunKnBSgQcIvXcYZR8QMrzBcXVKaZi4Zz5tdAKJ6xLtLtP04Ya8FxVrN RYQ2QxhLuzmA68of5b34iDv8qM1pSSg= Received: from mail-yb1-f198.google.com (mail-yb1-f198.google.com [209.85.219.198]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-367-lbe6vLRoPcO70WN52X9t2Q-1; Sun, 20 Oct 2019 11:46:22 -0400 Received: by mail-yb1-f198.google.com with SMTP id o141so8905425yba.15 for ; Sun, 20 Oct 2019 08:46:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=Alu6ppHvSW114ed3pBahWURj9wM8iWBEEGZ8MLoKgAk=; b=J5sEhSmk3aCQDPktQJMemloe6Sf7N17a9Xlp56vce72qfZeGklKmrpMRUsjWcHjuj4 QGD7mBVAuP/HhCuikad7pFAS1NSrkh8IjpAUT4UIJje6tcG+tQjkDq8HNFymzC3Ecwgg sGQvsHeivhcKjAdQtW72nA6E6o1L2b+MW80zka+Yz4bEB9cJOPtMGdqLZUA2YVI6p836 /PmtsBo/yCa+mh1gWFPC6fyU+fW7MNxIm5SYDraZXV/fKvmxJxulTw56pDMdfH3JPy5a tz8u9zKeUgECAi5+5YD9rR+b87EBQKnP9d9mNLsgOqkMUxjSXn4Gltm+FNrMyqUezk4Q dmpA== X-Gm-Message-State: APjAAAXxyQsj8PfyyEVFfDJ5E5dWexxgaQmE3KNLj6F9LHkwuhBF7ZD+ +9TXE5BR0PsjfTpgr8NruWbQ8m7KQRLvYxJY9TikthkV/xHxjmQZFxLuM6ro8aOEdgIBY2kKt+b BMpjojWuhMhgvNhh/wcfKdHRlo/WvYFCQ X-Received: by 2002:a25:2005:: with SMTP id g5mr11581344ybg.233.1571586381778; Sun, 20 Oct 2019 08:46:21 -0700 (PDT) X-Google-Smtp-Source: APXvYqxyKemkRcFRU3wzlgi/T4+K9AZ2BopYayuoVNBd36p+ggns4HBGKTFdfgg55BfQj8iXlviOeklLwD73HIE9Azs= X-Received: by 2002:a25:2005:: with SMTP id g5mr11581330ybg.233.1571586381452; Sun, 20 Oct 2019 08:46:21 -0700 (PDT) MIME-Version: 1.0 From: Tom Rix Date: Sun, 20 Oct 2019 08:46:10 -0700 Message-ID: Subject: [PATCH] xfrm : lock input tasklet skb queue To: steffen.klassert@secunet.com, herbert@gondor.apana.org.au, davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org X-MC-Unique: lbe6vLRoPcO70WN52X9t2Q-1 X-Mimecast-Spam-Score: 0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On PREEMPT_RT_FULL while running netperf, a corruption of the skb queue causes an oops. This appears to be caused by a race condition here __skb_queue_tail(&trans->queue, skb); tasklet_schedule(&trans->tasklet); Where the queue is changed before the tasklet is locked by tasklet_schedule. The fix is to use the skb queue lock. Signed-off-by: Tom Rix --- net/xfrm/xfrm_input.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c index 9b599ed66d97..226dead86828 100644 --- a/net/xfrm/xfrm_input.c +++ b/net/xfrm/xfrm_input.c @@ -758,12 +758,16 @@ static void xfrm_trans_reinject(unsigned long data) struct xfrm_trans_tasklet *trans = (void *)data; struct sk_buff_head queue; struct sk_buff *skb; + unsigned long flags; __skb_queue_head_init(&queue); + spin_lock_irqsave(&trans->queue.lock, flags); skb_queue_splice_init(&trans->queue, &queue); while ((skb = __skb_dequeue(&queue))) XFRM_TRANS_SKB_CB(skb)->finish(dev_net(skb->dev), NULL, skb); + + spin_unlock_irqrestore(&trans->queue.lock, flags); } int xfrm_trans_queue(struct sk_buff *skb, @@ -771,15 +775,20 @@ int xfrm_trans_queue(struct sk_buff *skb, struct sk_buff *)) { struct xfrm_trans_tasklet *trans; + unsigned long flags; trans = this_cpu_ptr(&xfrm_trans_tasklet); + spin_lock_irqsave(&trans->queue.lock, flags); - if (skb_queue_len(&trans->queue) >= netdev_max_backlog) + if (skb_queue_len(&trans->queue) >= netdev_max_backlog) { + spin_unlock_irqrestore(&trans->queue.lock, flags); return -ENOBUFS; + } XFRM_TRANS_SKB_CB(skb)->finish = finish; __skb_queue_tail(&trans->queue, skb); tasklet_schedule(&trans->tasklet); + spin_unlock_irqrestore(&trans->queue.lock, flags); return 0; } EXPORT_SYMBOL(xfrm_trans_queue);