linux/net/packet
Willem de Bruijn 9aad13b087 packet: fix reserve calculation
Commit b84bbaf7a6 ("packet: in packet_snd start writing at link
layer allocation") ensures that packet_snd always starts writing
the link layer header in reserved headroom allocated for this
purpose.

This is needed because packets may be shorter than hard_header_len,
in which case the space up to hard_header_len may be zeroed. But
that necessary padding is not accounted for in skb->len.

The fix, however, is buggy. It calls skb_push, which grows skb->len
when moving skb->data back. But in this case packet length should not
change.

Instead, call skb_reserve, which moves both skb->data and skb->tail
back, without changing length.

Fixes: b84bbaf7a6 ("packet: in packet_snd start writing at link layer allocation")
Reported-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-24 21:55:20 -04:00
..
Kconfig packet: Diag core and basic socket info dumping 2012-08-14 16:56:33 -07:00
Makefile packet: Diag core and basic socket info dumping 2012-08-14 16:56:33 -07:00
af_packet.c packet: fix reserve calculation 2018-05-24 21:55:20 -04:00
diag.c packet: pdiag_put_ring() should return TX_RING info for TPACKET_V3 2017-01-10 21:02:42 -05:00
internal.h packet: fix bitfield update race 2018-04-24 13:17:08 -04:00