linux-kernel - Re: [PATCH net-next v11 07/23] ovpn: introduce the ovpn

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <587e8015-a511-4e8e-af74-337d6383fd57@openvpn.net>
Date: Thu, 21 Nov 2024 22:29:45 +0100
From: Antonio Quartulli <antonio@...nvpn.net>
To: Sergey Ryazanov <ryazanov.s.a@...il.com>
Cc: Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski <kuba@...nel.org>,
 Paolo Abeni <pabeni@...hat.com>, Donald Hunter <donald.hunter@...il.com>,
 Shuah Khan <shuah@...nel.org>, sd@...asysnail.net,
 Andrew Lunn <andrew@...n.ch>, netdev@...r.kernel.org,
 linux-kernel@...r.kernel.org, linux-kselftest@...r.kernel.org
Subject: Re: [PATCH net-next v11 07/23] ovpn: introduce the ovpn_socket object

On 21/11/2024 00:34, Sergey Ryazanov wrote:
> On 19.11.2024 15:44, Antonio Quartulli wrote:
>> On 15/11/2024 15:28, Antonio Quartulli wrote:
>> [...]
>>>>> +}
>>>>> +
>>>>> +static struct ovpn_socket *ovpn_socket_get(struct socket *sock)
>>>>> +{
>>>>> +    struct ovpn_socket *ovpn_sock;
>>>>> +
>>>>> +    rcu_read_lock();
>>>>> +    ovpn_sock = rcu_dereference_sk_user_data(sock->sk);
>>>>> +    if (!ovpn_socket_hold(ovpn_sock)) {
>>>>> +        pr_warn("%s: found ovpn_socket with ref = 0\n", __func__);
>>>>
>>>> Should we be more specific here and print warning with 
>>>> netdev_warn(ovpn_sock->ovpn->dev, ...)?
>>>
>>> ACK must be an unnoticed leftover
>>
>> I take this back.
>> If refcounter is zero, I'd avoid accessing any field of the ovpn_sock 
>> object, thus the pr_warn() without any reference to the device.
> 
> If it's such unlikely scenario, then should it be:
> 
> if (WARN_ON(!ovpn_socket_hold(ovpn_sock)))
>      ovpn_sock = NULL;
> 
> ?

Yeah, makes sense.

Thanks!

> 
> -- 
> Sergey

-- 
Antonio Quartulli
OpenVPN Inc.