On Fri, 2020-10-02 at 21:53 +0200, Guillaume Nault wrote:
> Openvswitch allows to drop a packet's Ethernet header, therefore
> skb_mpls_push() and skb_mpls_pop() might be called with ethernet=true
> and mac_len=0. In that case the pointer passed to skb_mod_eth_type()
> doesn't point to an Ethernet header and the new Ethertype is written at
> unexpected locations.
>
> Fix this by verifying that mac_len is big enough to contain an Ethernet
> header.
>
> Fixes: fa4e0f8855fc ("net/sched: fix corrupted L2 header with MPLS 'push' and
> 'pop' actions")
> Signed-off-by: Guillaume Nault <gna...@redhat.com>
> ---
> Notes:
> - Found by code inspection.
> - Using commit fa4e0f8855fc for the Fixes tag because mac_len is
> needed for the test. The problem probably exists since openvswitch
> can pop the Ethernet header though.
>
> net/core/skbuff.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
Acked-by: Davide Caratti <dcara...@redhat.com>
thanks!
--
davide
