netdev - net: phylink: supported modes set to 0 with genphy sfp module

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-next>] [day] [month] [year] [list]

Date:   Mon, 11 May 2020 17:45:02 +0200
From:   Julien Beraud <julien.beraud@...lia.com>
To:     "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
        Russell King <linux@...linux.org.uk>
Cc:     Andrew Lunn <andrew@...n.ch>,
        Florian Fainelli <f.fainelli@...il.com>,
        Heiner Kallweit <hkallweit1@...il.com>
Subject: net: phylink: supported modes set to 0 with genphy sfp module

Following commit:

commit 52c956003a9d5bcae1f445f9dfd42b624adb6e87
Author: Russell King <rmk+kernel@...linux.org.uk>
Date:   Wed Dec 11 10:56:45 2019 +0000

     net: phylink: delay MAC configuration for copper SFP modules


In function phylink_sfp_connect_phy, phylink_sfp_config is called before 
phylink_attach_phy.

In the case of a genphy, the "supported" field of the phy_device is 
filled by:
phylink_attach_phy->phy_attach_direct->phy_probe->genphy_read_abilities.

It means that:

ret = phylink_sfp_config(pl, mode, phy->supported, phy->advertising);
will have phy->supported with no bits set, and then the first call to 
phylink_validate in phylink_sfp_config will return an error:

return phylink_is_empty_linkmode(supported) ? -EINVAL : 0;

this results in putting the sfp driver in "failed" state.

Thanks,
Julien Beraud