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  1. Aug 06, 2016
    • Ian Wienand's avatar
      OVS: Ignore negative headroom value · 5ef9f289
      Ian Wienand authored
      net_device->ndo_set_rx_headroom (introduced in
      871b642a) says
      
        "Setting a negtaive value reset the rx headroom
         to the default value".
      
      It seems that the OVS implementation in
      3a927bc7 overlooked this and sets
      dev->needed_headroom unconditionally.
      
      This doesn't have an immediate effect, but can mess up later
      LL_RESERVED_SPACE calculations, such as done in
      net/ipv6/mcast.c:mld_newpack.  For reference, this issue was found
      from a skb_panic raised there after the length calculations had given
      the wrong result.
      
      Note the other current users of this interface
      (drivers/net/tun.c:tun_set_headroom and
      drivers/net/veth.c:veth_set_rx_headroom) are both checking this
      correctly thus need no modification.
      
      Thanks to Ben for some pointers from the crash dumps!
      
      Cc: Benjamin Poirier <bpoirier@suse.com>
      Cc: Paolo Abeni <pabeni@redhat.com>
      Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1361414
      
      
      Signed-off-by: default avatarIan Wienand <iwienand@redhat.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      5ef9f289
  2. Aug 04, 2016
  3. Aug 03, 2016