ad7f402ae4
In some cases, the frontend may send a packet where the protocol headers
are spread across multiple slots. This would result in netback creating
an skb where the protocol headers spill over into the non-linear area.
Some drivers and NICs don't handle this properly resulting in an
interface reset or worse.
This issue was introduced by the removal of an unconditional skb pull in
the tx path to improve performance. Fix this without reintroducing the
pull by setting up grant copy ops for as many slots as needed to reach
the XEN_NETBACK_TX_COPY_LEN size. Adjust the rest of the code to handle
multiple copy operations per skb.
This is XSA-423 / CVE-2022-3643.
Fixes: 7e5d7753956b ("xen-netback: remove unconditional __pskb_pull_tail() in guest Tx path")
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Reviewed-by: Paul Durrant <paul@xen.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.