android_kernel_oneplus_msm8998/net/packet
Willem de Bruijn 7666b7098d packet: fix reserve calculation
[ Upstream commit 9aad13b087ab0a588cd68259de618f100053360e ]

Commit b84bbaf7a6c8 ("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: b84bbaf7a6c8 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-13 16:15:28 +02:00
..
af_packet.c packet: fix reserve calculation 2018-06-13 16:15:28 +02:00
diag.c netlink: make nlmsg_end() and genlmsg_end() void 2015-01-18 01:03:45 -05:00
internal.h packet: fix bitfield update race 2018-04-29 07:50:05 +02:00
Kconfig
Makefile