Re: BUG FIX: [PATCH RFC v3] memstick_check() memleak in kernel 6.1.0+ introduced pre 4.17

[Greg KH]

On Sat, Apr 01, 2023 at 08:33:36AM +0200, Greg KH wrote:
> On Sat, Apr 01, 2023 at 08:28:07AM +0200, Greg KH wrote:
> > On Sat, Apr 01, 2023 at 08:23:26AM +0200, Mirsad Goran Todorovac wrote:
> > > > This patch is implying that anyone who calls "dev_set_name()" also has
> > > > to do this hack, which shouldn't be the case at all.
> > > > 
> > > > thanks,
> > > > 
> > > > greg k-h
> > > 
> > > This is my best guess. Unless there is dev_free_name() or kobject_free_name(), I don't
> > > see a more sensible way to patch this up.
> > 
> > In sleeping on this, I think this has to move to the driver core.  I
> > don't understand why we haven't seen this before, except maybe no one
> > has really noticed before (i.e. we haven't had good leak detection tools
> > that run with removable devices?)
> > 
> > Anyway, let me see if I can come up with something this weekend, give me
> > a chance...
> 
> Wait, no, this already should be handled by the kobject core, look at
> kobject_cleanup(), at the bottom.  So your change should be merely
> duplicating the logic there that already runs when the struct device is
> freed, right?
> 
> So I don't understand why your change works, odd.  I need more coffee...

I think you got half of the change correctly.  This init code is a maze
of twisty passages, let me take your patch and tweak it a bit into
something that I think should work.  This looks to be only a memstick
issue, not a driver core issue (which makes me feel better.)

thanks,

greg k-h