lkml.org 
[lkml]   [2021]   [Dec]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] usb: gadget: u_ether: fix race in setting MAC address in setup phase
On Sat, Dec 04, 2021 at 08:42:52PM +0200, Marian Postevca wrote:
> Greg Kroah-Hartman <gregkh@linuxfoundation.org> writes:
>
> > On Tue, Nov 30, 2021 at 12:12:29AM +0200, Marian Postevca wrote:
> >> When listening for notifications through netlink of a new interface being
> >> registered, sporadically, it is possible for the MAC to be read as zero.
> >> The zero MAC address lasts a short period of time and then switches to a
> >> valid random MAC address.
> >>
> >> This causes problems for netd in Android, which assumes that the interface
> >> is malfunctioning and will not use it.
> >>
> >> In the good case we get this log:
> >> InterfaceController::getCfg() ifName usb0
> >> hwAddr 92:a8:f0:73:79:5b ipv4Addr 0.0.0.0 flags 0x1002
> >>
> >> In the error case we get these logs:
> >> InterfaceController::getCfg() ifName usb0
> >> hwAddr 00:00:00:00:00:00 ipv4Addr 0.0.0.0 flags 0x1002
> >>
> >> netd : interfaceGetCfg("usb0")
> >> netd : interfaceSetCfg() -> ServiceSpecificException
> >> (99, "[Cannot assign requested address] : ioctl() failed")
> >>
> >> The reason for the issue is the order in which the interface is setup,
> >> it is first registered through register_netdev() and after the MAC
> >> address is set.
> >>
> >> Fixed by first setting the MAC address of the net_device and after that
> >> calling register_netdev().
> >>
> >> Signed-off-by: Marian Postevca <posteuca@mutex.one>
> >> ---
> >> drivers/usb/gadget/function/u_ether.c | 16 ++++++----------
> >> 1 file changed, 6 insertions(+), 10 deletions(-)
> >
> > What commit does this fix? Should it go to stable kernel releases?
> >
> > thanks,
> >
> > greg k-h
>
> This fixes bcd4a1c40bee885e ("usb: gadget: u_ether: construct with
> default values and add setters/getters").
>
> I think it should go to stable kernel releases.
>
> Should I send a second version of the patch with a Fixes tag?

Yes please, and a cc: stable on the line after the fixes tag.

thanks,

greg k-h

\
 
 \ /
  Last update: 2021-12-04 19:48    [W:0.079 / U:6.584 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site