Re: [PATCH v5 6/7] vdpa: solidrun: Fix UB bug with devres

[Philipp Stanner <pstanner@xxxxxxxxxx>]

On Thu, 2024-08-29 at 11:10 -0400, Michael S. Tsirkin wrote:
> On Thu, Aug 29, 2024 at 04:49:50PM +0200, Philipp Stanner wrote:
> > On Thu, 2024-08-29 at 10:41 -0400, Michael S. Tsirkin wrote:
> > > On Thu, Aug 29, 2024 at 05:26:39PM +0300, Andy Shevchenko wrote:
> > > > On Thu, Aug 29, 2024 at 5:23 PM Michael S. Tsirkin
> > > > <mst@xxxxxxxxxx>
> > > > wrote:
> > > > > 
> > > > > On Thu, Aug 29, 2024 at 04:16:25PM +0200, Philipp Stanner
> > > > > wrote:
> > > > > > In psnet_open_pf_bar() and snet_open_vf_bar() a string
> > > > > > later
> > > > > > passed to
> > > > > > pcim_iomap_regions() is placed on the stack. Neither
> > > > > > pcim_iomap_regions() nor the functions it calls copy that
> > > > > > string.
> > > > > > 
> > > > > > Should the string later ever be used, this, consequently,
> > > > > > causes
> > > > > > undefined behavior since the stack frame will by then have
> > > > > > disappeared.
> > > > > > 
> > > > > > Fix the bug by allocating the strings on the heap through
> > > > > > devm_kasprintf().
> > > > > > 
> > > > > > Cc: stable@xxxxxxxxxxxxxxx    # v6.3
> > > > > > Fixes: 51a8f9d7f587 ("virtio: vdpa: new SolidNET DPU
> > > > > > driver.")
> > > > > > Reported-by: Christophe JAILLET
> > > > > > <christophe.jaillet@xxxxxxxxxx>
> > > > > > Closes:
> > > > > > https://lore.kernel.org/all/74e9109a-ac59-49e2-9b1d-d825c9c9f891@xxxxxxxxxx/
> > > > > > Suggested-by: Andy Shevchenko <andy@xxxxxxxxxx>
> > > > > > Signed-off-by: Philipp Stanner <pstanner@xxxxxxxxxx>
> > > > > 
> > > > > Post this separately, so I can apply?
> > > > 
> > > > Don't you use `b4`? With it it as simple as
> > > > 
> > > >   b4 am -P 6 $MSG_ID_OF_THIS_SERIES
> > > > 
> > > > -- 
> > > > With Best Regards,
> > > > Andy Shevchenko
> > > 
> > > I can do all kind of things, but if it's posted as part of a
> > > patchset,
> > > it is not clear to me this has been tested outside of the
> > > patchset.
> > > 
> > 
> > Separating it from the series would lead to merge conflicts,
> > because
> > patch 7 depends on it.
> > 
> > If you're responsible for vdpa in general I could send patches 6
> > and 7
> > separately to you.
> > 
> > But number 7 depends on number 1, because pcim_iounmap_region()
> > needs
> > to be public. So if patches 1-5 enter through a different tree than
> > yours, that could be a problem.
> > 
> > 
> > P.
> 
> Defer 1/7 until after the merge window, this is what is normally
> done.

1 cannot be deferred. Take a look what 1 does.

Your message is not comprehensible. Be so kind and write some more
sentences.
*What* is normally done? Sending patches? It's up to subsystem
maintainers to queue them for the right cycle.

> Adding new warnings is not nice, anyway.

What?



>