534fc31d09
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.
Fixes: ad7f402ae4f4 ("xen/netback: Ensure protocol headers don't fall in the non-linear area")
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Juergen Gross <jgross@suse.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.