This is a note to let you know that I've just added the patch titled
packet: round up linear to header len
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
packet-round-up-linear-to-header-len.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Tue Feb 14 17:03:08 PST 2017
From: Willem de Bruijn <willemb@xxxxxxxxxx>
Date: Tue, 7 Feb 2017 15:57:21 -0500
Subject: packet: round up linear to header len
From: Willem de Bruijn <willemb@xxxxxxxxxx>
[ Upstream commit 57031eb794906eea4e1c7b31dc1e2429c0af0c66 ]
Link layer protocols may unconditionally pull headers, as Ethernet
does in eth_type_trans. Ensure that the entire link layer header
always lies in the skb linear segment. tpacket_snd has such a check.
Extend this to packet_snd.
Variable length link layer headers complicate the computation
somewhat. Here skb->len may be smaller than dev->hard_header_len.
Round up the linear length to be at least as long as the smallest of
the two.
Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Signed-off-by: Willem de Bruijn <willemb@xxxxxxxxxx>
Acked-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/packet/af_packet.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -2813,7 +2813,7 @@ static int packet_snd(struct socket *soc
struct virtio_net_hdr vnet_hdr = { 0 };
int offset = 0;
struct packet_sock *po = pkt_sk(sk);
- int hlen, tlen;
+ int hlen, tlen, linear;
int extra_len = 0;
/*
@@ -2874,8 +2874,9 @@ static int packet_snd(struct socket *soc
err = -ENOBUFS;
hlen = LL_RESERVED_SPACE(dev);
tlen = dev->needed_tailroom;
- skb = packet_alloc_skb(sk, hlen + tlen, hlen, len,
- __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len),
+ linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
+ linear = max(linear, min_t(int, len, dev->hard_header_len));
+ skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear,
msg->msg_flags & MSG_DONTWAIT, &err);
if (skb == NULL)
goto out_unlock;
Patches currently in stable-queue which might be from willemb@xxxxxxxxxx are
queue-4.9/packet-round-up-linear-to-header-len.patch
queue-4.9/tun-read-vnet_hdr_sz-once.patch
queue-4.9/ipv6-fix-ip6_tnl_parse_tlv_enc_lim.patch
queue-4.9/net-introduce-device-min_header_len.patch
queue-4.9/macvtap-read-vnet_hdr_size-once.patch