Re: [PATCH] USB: core: Use `krealloc()` in `usb_cache_string()`

[Bence Csókás]

Hi,

On 3/15/26 10:47, Greg Kroah-Hartman wrote:
> On Sun, Mar 15, 2026 at 10:40:48AM +0100, Bence Csókás wrote:
> > > Also, how was this tested?
> >
> > I just compiled and booted it on my Arch box (with the original vendor
> > config), an AthlonII X2 PC. I'm now typing this mail on a USB keyboard and
> > mouse under Plasma, running this kernel :) I also plugged in a pendrive,
> > mounted it, `ls`'d the mount, unmounted, unplugged, and did this 2 more
> > times.
> >
> > I realize I should probably put this info under the dashes. I'll prepare a
> > v2.
>
> Try looking at the USB strings in the device, as that's the path here
> that is exercised.  Just using the device doesn't actually grab them
> from the descriptor table.

Sure.

  $ sudo lsusb -vvv | grep iProduct
  can't get debug descriptor: Resource temporarily unavailable
    iProduct                2 OHCI PCI host controller
    iProduct                2 HP USB Smart Card Keyboard
  can't get device qualifier: Resource temporarily unavailable
  can't get debug descriptor: Resource temporarily unavailable
    iProduct                2 USB OPTICAL MOUSE
  can't get debug descriptor: Resource temporarily unavailable
  can't get device qualifier: Resource temporarily unavailable
  can't get debug descriptor: Resource temporarily unavailable
    iProduct                2 EHCI Host Controller
    iProduct                2 EHCI Host Controller
  can't get device qualifier: Resource temporarily unavailable
  can't get debug descriptor: Resource temporarily unavailable
  can't get debug descriptor: Resource temporarily unavailable
    iProduct                2 Disk 2.0
    iProduct                2 EHCI Host Controller
  can't get device qualifier: Resource temporarily unavailable
  can't get debug descriptor: Resource temporarily unavailable
  can't get debug descriptor: Resource temporarily unavailable
    iProduct                2 OHCI PCI host controller
    iProduct                2 OHCI PCI host controller
  can't get debug descriptor: Resource temporarily unavailable
  can't get debug descriptor: Resource temporarily unavailable
    iProduct                2 OHCI PCI host controller

Are these -EAGAINs cause for concern?

> And sorry for the extra review, I'm a bit picky about this function, it
> was my first contribution to Linux way back in 1999 or so, and happen to
> know too much about USB descriptor strings :)

A good review is a thorough review.

> thanks,
>
> greg k-h

Bence