From: Cong Wang <xiyou.wangcong@gmail.com>
To: Richard Guy Briggs <rgb@redhat.com>
Cc: Linux Kernel Network Developers <netdev@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Eric Dumazet <edumazet@google.com>,
linux-audit@redhat.com, Dmitry Vyukov <dvyukov@google.com>
Subject: Re: [RFC PATCH v3] audit: use proper refcount locking on audit_sock
Date: Tue, 13 Dec 2016 21:36:37 -0800 [thread overview]
Message-ID: <CAM_iQpVuzYRAb4qFj1kPduxCUsAjkyik=qXriQcP6g7gPgyXRQ@mail.gmail.com> (raw)
In-Reply-To: <20161214040005.GL22660@madcap2.tricolour.ca>
On Tue, Dec 13, 2016 at 8:00 PM, Richard Guy Briggs <rgb@redhat.com> wrote:
> On 2016-12-13 16:19, Cong Wang wrote:
>> On Tue, Dec 13, 2016 at 7:03 AM, Richard Guy Briggs <rgb@redhat.com> wrote:
>> > @@ -1283,8 +1299,10 @@ static void __net_exit audit_net_exit(struct net *net)
>> > {
>> > struct audit_net *aunet = net_generic(net, audit_net_id);
>> > struct sock *sock = aunet->nlsk;
>> > + mutex_lock(&audit_cmd_mutex);
>> > if (sock == audit_sock)
>> > auditd_reset();
>> > + mutex_unlock(&audit_cmd_mutex);
>>
>> This still doesn't look correct to me, b/c here we release the audit_sock
>> refcnt twice:
>>
>> 1) inside audit_reset()
>
> The audit_reset() refcount decrement corresponds to a setting of
> audit_sock only if audit_sock is still non-NULL.
>
Hmm, thinking about it again, looks like the sock == audit_sock
and audit_sock != NULL checks can guarantee we are safe. So,
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
next prev parent reply other threads:[~2016-12-14 6:37 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CACT4Y+aG1+91U1PWMTwpE_6vbEuqG7CdLCM1H=3WVJWtz=>
[not found] ` <CAM_iQpVeLvfYV+1jX1ZKOntZim4roof4=>
2016-11-29 16:48 ` netlink: GPF in sock_sndtimeo Richard Guy Briggs
2016-11-29 23:13 ` Cong Wang
2016-11-30 4:52 ` Richard Guy Briggs
2016-12-09 6:02 ` Richard Guy Briggs
2016-12-09 6:57 ` Cong Wang
2016-12-09 11:01 ` Richard Guy Briggs
2016-12-10 4:13 ` Cong Wang
2016-12-10 7:40 ` Cong Wang
2016-12-12 10:07 ` Dmitry Vyukov
2016-12-13 7:51 ` Richard Guy Briggs
2016-12-13 8:28 ` Richard Guy Briggs
2016-12-12 10:02 ` Richard Guy Briggs
2016-12-12 10:03 ` [PATCH v2] audit: use proper refcount locking on audit_sock Richard Guy Briggs
2016-12-12 17:10 ` Paul Moore
2016-12-13 4:49 ` Richard Guy Briggs
2016-12-12 20:18 ` Paul Moore
2016-12-13 5:10 ` Richard Guy Briggs
2016-12-13 15:01 ` Richard Guy Briggs
2016-12-12 23:58 ` Cong Wang
2016-12-13 14:55 ` Richard Guy Briggs
2016-12-13 0:10 ` netlink: GPF in sock_sndtimeo Cong Wang
2016-12-13 10:52 ` Richard Guy Briggs
2016-12-14 0:17 ` Cong Wang
2016-12-14 4:17 ` Richard Guy Briggs
2016-12-13 15:03 ` [RFC PATCH v3] audit: use proper refcount locking on audit_sock Richard Guy Briggs
2016-12-13 20:50 ` Paul Moore
2016-12-14 0:19 ` Cong Wang
2016-12-14 4:00 ` Richard Guy Briggs
2016-12-14 5:36 ` Cong Wang [this message]
2016-12-09 10:49 ` netlink: GPF in sock_sndtimeo Dmitry Vyukov
2016-12-09 11:48 ` Richard Guy Briggs
2016-12-09 11:53 ` Dmitry Vyukov
2016-12-09 12:12 ` Richard Guy Briggs
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