Merge branch 'net-header-length-truncation'

Willem de Bruijn says:

====================
net: Fixes for header length truncation

Packets should not enter the stack with truncated link layer headers
and link layer headers should always be stored in the skb linear
segment.

Patch 1 ensures the first for PF_PACKET sockets
Patch 2 ensures the second for PF_PACKET GSO sockets without tx_ring
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller 2017-02-08 13:56:38 -05:00
commit 9538132a9f
4 changed files with 10 additions and 3 deletions

View File

@ -164,6 +164,7 @@ static void loopback_setup(struct net_device *dev)
{ {
dev->mtu = 64 * 1024; dev->mtu = 64 * 1024;
dev->hard_header_len = ETH_HLEN; /* 14 */ dev->hard_header_len = ETH_HLEN; /* 14 */
dev->min_header_len = ETH_HLEN; /* 14 */
dev->addr_len = ETH_ALEN; /* 6 */ dev->addr_len = ETH_ALEN; /* 6 */
dev->type = ARPHRD_LOOPBACK; /* 0x0001*/ dev->type = ARPHRD_LOOPBACK; /* 0x0001*/
dev->flags = IFF_LOOPBACK; dev->flags = IFF_LOOPBACK;

View File

@ -1511,6 +1511,7 @@ enum netdev_priv_flags {
* @max_mtu: Interface Maximum MTU value * @max_mtu: Interface Maximum MTU value
* @type: Interface hardware type * @type: Interface hardware type
* @hard_header_len: Maximum hardware header length. * @hard_header_len: Maximum hardware header length.
* @min_header_len: Minimum hardware header length
* *
* @needed_headroom: Extra headroom the hardware may need, but not in all * @needed_headroom: Extra headroom the hardware may need, but not in all
* cases can this be guaranteed * cases can this be guaranteed
@ -1728,6 +1729,7 @@ struct net_device {
unsigned int max_mtu; unsigned int max_mtu;
unsigned short type; unsigned short type;
unsigned short hard_header_len; unsigned short hard_header_len;
unsigned short min_header_len;
unsigned short needed_headroom; unsigned short needed_headroom;
unsigned short needed_tailroom; unsigned short needed_tailroom;
@ -2694,6 +2696,8 @@ static inline bool dev_validate_header(const struct net_device *dev,
{ {
if (likely(len >= dev->hard_header_len)) if (likely(len >= dev->hard_header_len))
return true; return true;
if (len < dev->min_header_len)
return false;
if (capable(CAP_SYS_RAWIO)) { if (capable(CAP_SYS_RAWIO)) {
memset(ll_header + len, 0, dev->hard_header_len - len); memset(ll_header + len, 0, dev->hard_header_len - len);

View File

@ -356,6 +356,7 @@ void ether_setup(struct net_device *dev)
dev->header_ops = &eth_header_ops; dev->header_ops = &eth_header_ops;
dev->type = ARPHRD_ETHER; dev->type = ARPHRD_ETHER;
dev->hard_header_len = ETH_HLEN; dev->hard_header_len = ETH_HLEN;
dev->min_header_len = ETH_HLEN;
dev->mtu = ETH_DATA_LEN; dev->mtu = ETH_DATA_LEN;
dev->min_mtu = ETH_MIN_MTU; dev->min_mtu = ETH_MIN_MTU;
dev->max_mtu = ETH_DATA_LEN; dev->max_mtu = ETH_DATA_LEN;

View File

@ -2755,7 +2755,7 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
struct virtio_net_hdr vnet_hdr = { 0 }; struct virtio_net_hdr vnet_hdr = { 0 };
int offset = 0; int offset = 0;
struct packet_sock *po = pkt_sk(sk); struct packet_sock *po = pkt_sk(sk);
int hlen, tlen; int hlen, tlen, linear;
int extra_len = 0; int extra_len = 0;
/* /*
@ -2816,8 +2816,9 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len)
err = -ENOBUFS; err = -ENOBUFS;
hlen = LL_RESERVED_SPACE(dev); hlen = LL_RESERVED_SPACE(dev);
tlen = dev->needed_tailroom; tlen = dev->needed_tailroom;
skb = packet_alloc_skb(sk, hlen + tlen, hlen, len, linear = __virtio16_to_cpu(vio_le(), vnet_hdr.hdr_len);
__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); msg->msg_flags & MSG_DONTWAIT, &err);
if (skb == NULL) if (skb == NULL)
goto out_unlock; goto out_unlock;