From: Dan Carpenter <dan.carpenter@oracle.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>,
Jiri Pirko <jiri@resnulli.us>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Mohit Bhasi <mohitbhasi1998@gmail.com>,
"Mohit P. Tahiliani" <tahiliani@nitk.edu.in>,
"V. Saicharan" <vsaicharan1998@gmail.com>,
Gautam Ramakrishnan <gautamramk@gmail.com>,
Linux Kernel Network Developers <netdev@vger.kernel.org>,
kernel-janitors@vger.kernel.org
Subject: Re: [PATCH net] net: sched: prevent a use after free
Date: Mon, 3 Feb 2020 11:38:53 +0300 [thread overview]
Message-ID: <20200203083853.GH11068@kadam> (raw)
In-Reply-To: <CAM_iQpUYv9vEVpYc-WfMNfCc9QaBzmTYs66-GEfwOKiqOXHxew@mail.gmail.com>
On Sat, Feb 01, 2020 at 11:38:43AM -0800, Cong Wang wrote:
> On Thu, Jan 30, 2020 at 10:57 PM Dan Carpenter <dan.carpenter@oracle.com> wrote:
> >
> > The code calls kfree_skb(skb); and then re-uses "skb" on the next line.
> > Let's re-order these lines to solve the problem.
> >
> > Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler")
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > ---
> > net/sched/sch_fq_pie.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/net/sched/sch_fq_pie.c b/net/sched/sch_fq_pie.c
> > index bbd0dea6b6b9..78472e0773e9 100644
> > --- a/net/sched/sch_fq_pie.c
> > +++ b/net/sched/sch_fq_pie.c
> > @@ -349,9 +349,9 @@ static int fq_pie_change(struct Qdisc *sch, struct nlattr *opt,
> > while (sch->q.qlen > sch->limit) {
> > struct sk_buff *skb = fq_pie_qdisc_dequeue(sch);
> >
> > - kfree_skb(skb);
> > len_dropped += qdisc_pkt_len(skb);
> > num_dropped += 1;
> > + kfree_skb(skb);
>
> Or even better: use rtnl_kfree_skbs().
Why is that better?
regards,
dan carpenter
next prev parent reply other threads:[~2020-02-03 8:39 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-31 6:56 [PATCH net] net: sched: prevent a use after free Dan Carpenter
2020-02-01 19:38 ` Cong Wang
2020-02-03 8:38 ` Dan Carpenter [this message]
2020-02-03 19:58 ` Cong Wang
2020-02-03 20:33 ` Cong Wang
2020-02-05 11:53 ` [PATCH v2 " Dan Carpenter
2020-02-05 18:03 ` Cong Wang
2020-02-06 13:01 ` David Miller
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=20200203083853.GH11068@kadam \
--to=dan.carpenter@oracle.com \
--cc=davem@davemloft.net \
--cc=gautamramk@gmail.com \
--cc=jhs@mojatatu.com \
--cc=jiri@resnulli.us \
--cc=kernel-janitors@vger.kernel.org \
--cc=kuba@kernel.org \
--cc=mohitbhasi1998@gmail.com \
--cc=netdev@vger.kernel.org \
--cc=tahiliani@nitk.edu.in \
--cc=vsaicharan1998@gmail.com \
--cc=xiyou.wangcong@gmail.com \
/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).