Re: [PATCH net] net: phy: Warn if phy is attached when removing

From: Jakub Kicinski
Date: Fri Aug 19 2022 - 19:45:33 EST


On Tue, 16 Aug 2022 12:37:01 -0400 Sean Anderson wrote:
> netdevs using phylib can be oopsed from userspace in the following
> manner:
>
> $ ip link set $iface up
> $ echo $(basename $(readlink /sys/class/net/$iface/phydev)) > \
> /sys/class/net/$iface/phydev/driver/unbind
> $ ip link set $iface down
>
> However, the traceback provided is a bit too late, since it does not
> capture the root of the problem (unbinding the driver). It's also
> possible that the memory has been reallocated if sufficient time passes
> between when the phy is detached and when the netdev touches the phy
> (which could result in silent memory corruption). Add a warning at the
> source of the problem. A future patch could make this more robust by
> calling dev_close.

FWIW, I think DaveM marked this patch as changes requested.

I don't really know enough to have an opinion.

PHY maintainers, anyone willing to cast a vote?