206199412b
[ Upstream commit c769accdf3d8a103940bea2979b65556718567e9 ]
In some situation vlan packets do not have ethernet headers. One example
is packets from tun devices. Users can specify vlan protocol in tun_pi
field instead of IP protocol. When we have a vlan device with reorder_hdr
disabled on top of the tun device, such packets from tun devices are
untagged in skb_vlan_untag() and vlan headers will be inserted back in
vlan_insert_inner_tag().
vlan_insert_inner_tag() however did not expect packets without ethernet
headers, so in such a case size argument for memmove() underflowed.
We don't need to copy headers for packets which do not have preceding
headers of vlan headers, so skip memmove() in that case.
Also don't write vlan protocol in skb->data when it does not have enough
room for it.
Fixes: cbe7128c4b92 ("vlan: Fix out of order vlan headers with reorder header off")
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.