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authorHerbert Xu <herbert@gondor.apana.org.au>2014-11-03 04:30:14 +0800
committerDavid S. Miller <davem@davemloft.net>2014-11-03 14:27:06 -0500
commit2eb783c43e7cf807a45899c10ed556b6dc116625 (patch)
tree15b3ea5b89ea7f75965d3ce1c4eba43d69c182c6 /drivers/net/tun.c
parenta8f9bfdf982e2b1fb9f094e4de9ab08c57f3d2fd (diff)
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: 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>
Diffstat (limited to 'drivers/net/tun.c')
-rw-r--r--drivers/net/tun.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 57e6bf75a632..9dd3746994a4 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -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;