Re: [PATCH v4 5/9] pcie_sriov: Validate NumVFs

[Akihiko Odaki]

On 2024/02/14 17:58, Michael Tokarev wrote:
> 14.02.2024 08:13, Akihiko Odaki wrote:
> > The guest may write NumVFs greater than TotalVFs and that can lead
> > to buffer overflow in VF implementations.
>
> This seems to be stable-worthy (Cc'd), and maybe even CVE-worthy?

Perhaps so. The scope of the bug is limited to emulated SR-IOV devices, 
and I think nobody use them except for development, but it may be still 
nice to have a CVE.

Can anyone help assign a CVE? I don't know the procedure.

Regards,
Akihiko Odaki

> Thanks,
>
> /mjt
>
> > Fixes: 7c0fa8dff811 ("pcie: Add support for Single Root I/O 
> > Virtualization (SR/IOV)")
> > Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
> > ---
> >   hw/pci/pcie_sriov.c | 3 +++
> >   1 file changed, 3 insertions(+)
> >
> > diff --git a/hw/pci/pcie_sriov.c b/hw/pci/pcie_sriov.c
> > index a1fe65f5d801..da209b7f47fd 100644
> > --- a/hw/pci/pcie_sriov.c
> > +++ b/hw/pci/pcie_sriov.c
> > @@ -176,6 +176,9 @@ static void register_vfs(PCIDevice *dev)
> >       assert(sriov_cap > 0);
> >       num_vfs = pci_get_word(dev->config + sriov_cap + PCI_SRIOV_NUM_VF);
> > +    if (num_vfs > pci_get_word(dev->config + sriov_cap + 
> > PCI_SRIOV_TOTAL_VF)) {
> > +        return;
> > +    }
> >       dev->exp.sriov_pf.vf = g_new(PCIDevice *, num_vfs);