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

["Bence Csókás" <bence98@sch.bme.hu>]

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