p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

tun: Fix TUN_PKT_STRIP setting 

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: f43798c276 ("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>
This commit is contained in:
Herbert Xu 2014-11-03 04:30:14 +08:00 committed by David S. Miller
parent a8f9bfdf98
commit 2eb783c43e
1 changed files with 8 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/net/tun.c
View File

@ -1236,15 +1236,19 @@ static ssize_t tun_put_user(struct tun_struct *tun,
ssize_t total = 0;
int vlan_offset = 0, copied;
int vlan_hlen = 0;
int vnet_hdr_sz = 0;
if (vlan_tx_tag_present(skb))
vlan_hlen = VLAN_HLEN;
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 (len < skb->len) {
if (len < skb->len + vlan_hlen + vnet_hdr_sz) {
/* Packet will be striped */
pi.flags |= TUN_PKT_STRIP;
}
@ -1254,9 +1258,9 @@ static ssize_t tun_put_user(struct tun_struct *tun,
total += sizeof(pi);
}
if (tun->flags & TUN_VNET_HDR) {
if (vnet_hdr_sz) {
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)) {
@ -1298,7 +1302,7 @@ static ssize_t tun_put_user(struct tun_struct *tun,
if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
sizeof(gso))))
return -EFAULT;
total += tun->vnet_hdr_sz;
total += vnet_hdr_sz;
}
copied = total;