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  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]
Date:   Thu, 17 Sep 2020 09:32:03 -0700
From:   Florian Fainelli <f.fainelli@...il.com>
To:     Andrew Lunn <andrew@...n.ch>
Cc:     netdev@...r.kernel.org, hkallweit1@...il.com, kuba@...nel.org,
        davem@...emloft.net
Subject: Re: [PATCH net 1/2] net: phy: Avoid NPD upon phy_detach() when driver
 is unbound



On 9/17/2020 6:15 AM, Andrew Lunn wrote:
> On Wed, Sep 16, 2020 at 08:43:09PM -0700, Florian Fainelli wrote:
>> If we have unbound the PHY driver prior to calling phy_detach() (often
>> via phy_disconnect()) then we can cause a NULL pointer de-reference
>> accessing the driver owner member. The steps to reproduce are:
>>
>> echo unimac-mdio-0:01 > /sys/class/net/eth0/phydev/driver/unbind
>> ip link set eth0 down
> 
> Hi Florian
> 
> How forceful is this unbind? Can we actually block it while the
> interface is up? Or returning -EBUSY would make sense.

It it not forceful, you can unbind the PHY driver from underneath the 
net_device and nothing bad happens, really. This is not a very realistic 
or practical use case, but several years ago, I went into making sure we 
would not create NPD if that happened.
-- 
Florian

Powered by blists - more mailing lists