Re: CVE-2023-53502: xen/netback: Fix buffer overrun triggered by unusual packet

[Greg KH]

On Wed, Oct 01, 2025 at 02:05:47PM +0200, Juergen Gross wrote:
> On 01.10.25 13:45, Greg Kroah-Hartman wrote:
> > From: Greg Kroah-Hartman <gregkh@xxxxxxxxxx>
> > 
> > Description
> > ===========
> > 
> > In the Linux kernel, the following vulnerability has been resolved:
> > 
> > xen/netback: Fix buffer overrun triggered by unusual packet
> > 
> > It is possible that a guest can send a packet that contains a head + 18
> > slots and yet has a len <= XEN_NETBACK_TX_COPY_LEN. This causes nr_slots
> > to underflow in xenvif_get_requests() which then causes the subsequent
> > loop's termination condition to be wrong, causing a buffer overrun of
> > queue->tx_map_ops.
> > 
> > Rework the code to account for the extra frag_overflow slots.
> > 
> > This is CVE-2023-34319 / XSA-432.
> > 
> > The Linux kernel CVE team has assigned CVE-2023-53502 to this issue.
> 
> As can be seen right above your line "The Linux kernel CVE team ..."
> this issue has been handled by the Xen security team already and a
> CVE is assigned since then.

Ugh, then why doesn't that CVE reference this commit properly?  I do
sweep all old CVE assignments when doing this old-rereview.  Any chance
you can go and update these CVE entries with the proper git ids?

> Please revoke your CVE assignment.

Will go do so now, thanks for catching this.

greg k-h