netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Lars Persson <lars.persson@axis.com>
To: netdev@vger.kernel.org
Cc: jhs@mojatatu.com, linux-kernel@vger.kernel.org,
	Lars Persson <larper@axis.com>
Subject: [PATCH net] net: sched: do not requeue a NULL skb
Date: Wed,  6 Apr 2016 15:10:14 +0200	[thread overview]
Message-ID: <1459948214-735-1-git-send-email-larper@axis.com> (raw)

A failure in validate_xmit_skb_list() triggered an unconditional call
to dev_requeue_skb with skb=NULL. This slowly grows the queue
discipline's qlen count until all traffic through the queue stops.

Fixes: 55a93b3ea780 ("qdisc: validate skb without holding lock")
Signed-off-by: Lars Persson <larper@axis.com>
---
 net/sched/sch_generic.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index f18c350..1031536 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -165,6 +165,9 @@ int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
 			skb = dev_hard_start_xmit(skb, dev, txq, &ret);
 
 		HARD_TX_UNLOCK(dev, txq);
+	} else {
+		spin_lock(root_lock);
+		return qdisc_qlen(q);
 	}
 	spin_lock(root_lock);
 
-- 
2.1.4

             reply	other threads:[~2016-04-06 13:10 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-04-06 13:10 Lars Persson [this message]
2016-04-06 17:14 ` [PATCH net] net: sched: do not requeue a NULL skb Cong Wang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1459948214-735-1-git-send-email-larper@axis.com \
    --to=lars.persson@axis.com \
    --cc=jhs@mojatatu.com \
    --cc=larper@axis.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).