diff options
| author | Willem de Bruijn <willemb@google.com> | 2017-02-07 15:57:21 -0500 |
|---|---|---|
| committer | Mister Oyster <oysterized@gmail.com> | 2017-07-04 11:51:33 +0200 |
| commit | 0458cb3e231dcab869c765a9509660383b83ff33 (patch) | |
| tree | 81d522b6ccbf53a2a3007752e7bd617454147055 /net/packet | |
| parent | 81bdc97a16cb396cc748108a5042709b00713e75 (diff) | |
packet: round up linear to header len
commit 57031eb794906eea4e1c7b31dc1e2429c0af0c66 upstream.
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.
[js] no virtio helpers in 3.12
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Diffstat (limited to 'net/packet')
| -rw-r--r-- | net/packet/af_packet.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 9cf3e2110..4dfa37b82 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2243,7 +2243,7 @@ static int packet_snd(struct socket *sock, int vnet_hdr_len; struct packet_sock *po = pkt_sk(sk); unsigned short gso_type = 0; - int hlen, tlen; + int hlen, tlen, linear; int extra_len = 0; /* @@ -2337,7 +2337,9 @@ static int packet_snd(struct socket *sock, err = -ENOBUFS; hlen = LL_RESERVED_SPACE(dev); tlen = dev->needed_tailroom; - skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, vnet_hdr.hdr_len, + linear = 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; |