linux-kernel - Re: uhid: broken interface: 32/64-bit compatibility

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

Date:	Fri, 15 Feb 2013 14:00:22 +0200
From:	Johan Hedberg <johan.hedberg@...il.com>
To:	David Herrmann <dh.herrmann@...glemail.com>
Cc:	"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
	linux-api@...r.kernel.org, linux-input@...r.kernel.org,
	Jiri Kosina <jkosina@...e.cz>,
	RavindranathX Doddi <ravindranathx.doddi@...el.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	linux-kernel@...r.kernel.org, Marcel Holtmann <marcel@...tmann.org>
Subject: Re: uhid: broken interface: 32/64-bit compatibility

Hi David,

On Fri, Feb 15, 2013, David Herrmann wrote:
> On Fri, Feb 15, 2013 at 12:29 PM, Kirill A. Shutemov
> <kirill.shutemov@...ux.intel.com> wrote:
> > Hi David and all,
> >
> > There's claim in uhid.h that the interface is "compatible even between
> > architectures". But it obviously is not true: struct uhid_create_req
> > contains pointer which breaks everything.
> >
> > The easy way to demonstrate the issue is compile uhid-example.c with -m32
> > and try to run it on 64 bit kernel. Creating of the device will fail.
> 
> Indeed, we missed that. We should probably also notify the HIDP
> developers as "struct hidp_connadd_req" suffers from the same
> problems. (CC'ed)
> 
> > I don't see an easy way to fix this. Few options:
> >
> > 1. Replace the pointer with u64. It will fix the issue, but it breaks ABI
> >    which is never a good idea. Not sure how many users interface already
> >    has.
> 
> The only users I am aware of is an HID debugging tool and experimental
> HoG Bluetooth support (bluez). Maybe Marcel or Johan can comment
> whether this is already used by bluez-5? If it is, then we shouldn't
> break ABI and go with #2+#3. Otherwise, I think changing to u64 should
> be ok.
> On the other hand, it would break any future build for older stable
> kernels so not breaking ABI is probably the best idea. Any comments? I
> can add a COMPAT fix and a comment to fix this in the next version of
> UHID_CREATE.

The HoG code in BlueZ 5 does indeed use this API and it's also not
anymore behind any kind of experimental flag (i.e. it is an officially
supported feature).

Johan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/