Re: [PATCH] HID: usbhid: sanitize hid->uniq against non-printable bytes

[Alan Stern]

On Thu, Apr 23, 2026 at 11:49:02AM +0200, Oliver Neukum wrote:
> 
> 
> On 23.04.26 11:29, Greg KH wrote:
> > On Thu, Apr 23, 2026 at 05:55:00AM +0000, Eric Naim wrote:
> > > On 4/18/26 3:14 PM, Greg KH wrote:
> 
> > > [1] https://github.com/systemd/systemd/issues/41339#issuecomment-4266429563
> > 
> > It's either up to the kernel, or every single userspace program that
> > reads the strings from a device.  Might as well do it in one place,
> > right?
> 
> No, because that puts the assumption that user space is not interested
> in what the device actually returns and uses these strings just
> for printing.
> Eg. you can no longer use this in a udev rule.

Also, the USB spec doesn't say anything about what characters are or 
aren't allowed in a string descriptor.  Anything, even a control 
character, is valid.  The kernel should not rule them and certainly 
shouldn't truncate a string descriptor.

Alan Stern