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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2014-11-03 04:30:14 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-11-03 14:27:06 -0500 |
| commit | 2eb783c43e7cf807a45899c10ed556b6dc116625 (patch) | |
| tree | 15b3ea5b89ea7f75965d3ce1c4eba43d69c182c6 /drivers/net/tun.c | |
| parent | a8f9bfdf982e2b1fb9f094e4de9ab08c57f3d2fd (diff) | |
| download | linux-2eb783c43e7cf807a45899c10ed556b6dc116625.tar.gz linux-2eb783c43e7cf807a45899c10ed556b6dc116625.tar.bz2 linux-2eb783c43e7cf807a45899c10ed556b6dc116625.zip | |
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.c | 12 |
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; |