4.9-stable review patch. If anyone has any objections, please let me know.
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From: Matthias Schiffer mschiffer@universe-factory.net
[ Upstream commit abd6360591d3f8259f41c34e31ac4826dfe621b8 ]
eth_type_trans() internally calls skb_pull(), which does not adjust the skb checksum; skb_postpull_rcsum() is necessary to avoid log spam of the form "bat0: hw csum failure" when packets with CHECKSUM_COMPLETE are received.
Note that in usual setups, packets don't reach batman-adv with CHECKSUM_COMPLETE (I assume NICs bail out of checksumming when they see batadv's ethtype?), which is why the log messages do not occur on every system using batman-adv. I could reproduce this issue by stacking batman-adv on top of a VXLAN interface.
Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol") Tested-by: Maximilian Wilhelm max@sdn.clinic Signed-off-by: Matthias Schiffer mschiffer@universe-factory.net Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Simon Wunderlich sw@simonwunderlich.de Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/batman-adv/soft-interface.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-)
--- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -448,13 +448,7 @@ void batadv_interface_rx(struct net_devi
/* skb->dev & skb->pkt_type are set here */ skb->protocol = eth_type_trans(skb, soft_iface); - - /* should not be necessary anymore as we use skb_pull_rcsum() - * TODO: please verify this and remove this TODO - * -- Dec 21st 2009, Simon Wunderlich - */ - - /* skb->ip_summed = CHECKSUM_UNNECESSARY; */ + skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
batadv_inc_counter(bat_priv, BATADV_CNT_RX); batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,