commit
2eb783c43e7cf807a45899c10ed556b6dc116625 upstream.
We set the flag TUN_PKT_STRIP if the user buffer provided is too
small to contain the entire packet plus meta-data. However, this
has been broken ever since we added GSO meta-data. VLAN acceleration
also has the same problem.
This patch fixes this by taking both into account when setting the
TUN_PKT_STRIP flag.
The fact that this has been broken for six years without anyone
realising means that nobody actually uses this flag.
Fixes:
f43798c27684 ("tun: Allow GSO using virtio_net_hdr")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2:
- No VLAN acceleration support
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
{
struct tun_pi pi = { 0, skb->protocol };
ssize_t total = 0;
{
struct tun_pi pi = { 0, skb->protocol };
ssize_t total = 0;
+ int vnet_hdr_sz = 0;
+
+ if (tun->flags & TUN_VNET_HDR)
+ vnet_hdr_sz = tun->vnet_hdr_sz;
if (!(tun->flags & TUN_NO_PI)) {
if ((len -= sizeof(pi)) < 0)
return -EINVAL;
if (!(tun->flags & TUN_NO_PI)) {
if ((len -= sizeof(pi)) < 0)
return -EINVAL;
+ if (len < skb->len + vnet_hdr_sz) {
/* Packet will be striped */
pi.flags |= TUN_PKT_STRIP;
}
/* Packet will be striped */
pi.flags |= TUN_PKT_STRIP;
}
- if (tun->flags & TUN_VNET_HDR) {
struct virtio_net_hdr gso = { 0 }; /* no info leak */
struct virtio_net_hdr gso = { 0 }; /* no info leak */
- if ((len -= tun->vnet_hdr_sz) < 0)
+ if ((len -= vnet_hdr_sz) < 0)
return -EINVAL;
if (skb_is_gso(skb)) {
return -EINVAL;
if (skb_is_gso(skb)) {
if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
sizeof(gso))))
return -EFAULT;
if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
sizeof(gso))))
return -EFAULT;
- total += tun->vnet_hdr_sz;
}
len = min_t(int, skb->len, len);
}
len = min_t(int, skb->len, len);