netdev - Re: [PATCH net v1] dev_ioctl: fix the type of ifr

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]

Message-ID: <20240910220016.160ed631@hermes.local>
Date: Tue, 10 Sep 2024 22:00:16 -0700
From: Stephen Hemminger <stephen@...workplumber.org>
To: Atlas Yu <atlas.yu@...onical.com>
Cc: kuba@...nel.org, edumazet@...gle.com, davem@...emloft.net,
 pabeni@...hat.com, netdev@...r.kernel.org
Subject: Re: [PATCH net v1] dev_ioctl: fix the type of ifr_flags

On Wed, 11 Sep 2024 12:17:24 +0800
Atlas Yu <atlas.yu@...onical.com> wrote:

> On Wed, Sep 11, 2024 at 11:56 AM
> Stephen Hemminger <stephen@...workplumber.org> wrote:
> 
> > On Wed, 11 Sep 2024 11:46:08 +0800
> > Atlas Yu <atlas.yu@...onical.com> wrote:  
> > > diff --git a/include/uapi/linux/if.h b/include/uapi/linux/if.h
> > > index 797ba2c1562a..b612b6cd7446 100644
> > > --- a/include/uapi/linux/if.h
> > > +++ b/include/uapi/linux/if.h
> > > @@ -244,7 +244,7 @@ struct ifreq {
> > >               struct  sockaddr ifru_broadaddr;
> > >               struct  sockaddr ifru_netmask;
> > >               struct  sockaddr ifru_hwaddr;
> > > -             short   ifru_flags;
> > > +             unsigned int    ifru_flags;
> > >               int     ifru_ivalue;
> > >               int     ifru_mtu;
> > >               struct  ifmap ifru_map;  
> >
> > NAK
> > This breaks userspace ABI. There is no guarantee that
> > older application correctly zeros the upper flag bits.  
> 
> Thanks, any suggestions though? How about introducing
> another ioctl request for these extended bits.

Doing anything with ioctl's is hard, there are so many layers to deal with.
Mostly, networking has treated ioctl's as legacy API and switched to using
netlink for any new features.