From: Patrick McHardy <kaber@trash.net>
To: Cong Wang <cwang@twopensource.com>
Cc: John Fastabend <john.fastabend@gmail.com>,
wang.bo116@zte.com.cn, David Miller <davem@davemloft.net>,
netdev <netdev@vger.kernel.org>,
cui.yunfeng@zte.com.cn
Subject: Re: [PATCH net] net/sched: Fix use of wild pointer in mq_destroy() when qdisc_alloc fail
Date: Fri, 24 Oct 2014 20:14:19 +0100 [thread overview]
Message-ID: <20141024191418.GA8842@acer.localdomain> (raw)
In-Reply-To: <CAHA+R7P+nGXc93e_-u5Bvmr5Ri8CCg9FAgc+R7fJT7mJ5sBFwQ@mail.gmail.com>
On Fri, Oct 24, 2014 at 11:13:56AM -0700, Cong Wang wrote:
> On Fri, Oct 24, 2014 at 10:49 AM, John Fastabend
> <john.fastabend@gmail.com> wrote:
> >
> > Patch looks fine, another way to fix this would be drop the
> > mq_destroy() call in the error path. I'm not convinced one
> > is any better than the other but maybe some other folks have
> > opinions, it seems a bit wrong to call mq_destroy twice so in
> > that sense it may be a bit nicer to drop the mq_destroy().
>
> Dropping mq_destroy() in error path is indeed better,
> because upper layer does cleanup intentionally.
> Look at what other qdisc's do. :)
I would argue that the qdisc_destroy() call in qdisc_create_dflt()
is wrong, it should instead free the qdisc and release the module
reference manually as done in qdisc_create().
qdisc_destroy() should only be called for fully initialized qdiscs.
next prev parent reply other threads:[~2014-10-24 19:20 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-24 8:34 [PATCH net] net/sched: Fix use of wild pointer in mq_destroy() when qdisc_alloc fail wang.bo116
2014-10-24 17:49 ` John Fastabend
2014-10-24 18:13 ` Cong Wang
2014-10-24 18:58 ` Cong Wang
2014-10-24 19:14 ` Patrick McHardy [this message]
2014-10-24 20:52 ` Cong Wang
2014-10-24 21:45 ` Patrick McHardy
2014-10-24 22:17 ` Cong Wang
2014-10-25 0:33 ` Patrick McHardy
2014-10-25 0:57 ` Cong Wang
2014-10-25 1:33 ` Patrick McHardy
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