[PATCH] usb: core: buffer: avoid NULL pointer dereferrence

Alan Stern
2016-04-08T15:21:05Z

On Fri, 8 Apr 2016, Greg Kroah-Hartman wrote:

> On Fri, Apr 08, 2016 at 05:08:03PM +0800, Chunfeng Yun wrote:
> > NULL pointer dereferrence will happen when class driver
> > wants to allocate zero length buffer and pool_max[0]
> > can't be used, so skip reserved pool in this case.
>
> Why would a driver want to allocate a 0 length buffer? What driver does
> this?
>
> Shouldn't we fix that issue instead?

And even if a driver does want to allocate a 0-length buffer, shouldn't
the function simply return early instead of running through all its
calculations?

Alan Stern