1 files changed, 17 insertions, 11 deletions

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 7302398f0b1f..9dd3746994a4 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1235,12 +1235,20 @@ static ssize_t tun_put_user(struct tun_struct *tun,
         struct tun_pi pi = { 0, skb->protocol };
         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;
                 }
@@ -1250,9 +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)) {
@@ -1284,7 +1292,8 @@ static ssize_t tun_put_user(struct tun_struct *tun,
 
                 if (skb->ip_summed == CHECKSUM_PARTIAL) {
                         gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-                        gso.csum_start = skb_checksum_start_offset(skb);
+                        gso.csum_start = skb_checksum_start_offset(skb) +
+                                         vlan_hlen;
                         gso.csum_offset = skb->csum_offset;
                 } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
                         gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
@@ -1293,14 +1302,13 @@ 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;
-        total += skb->len;
-        if (!vlan_tx_tag_present(skb)) {
-                len = min_t(int, skb->len, len);
-        } else {
+        len = min_t(int, skb->len + vlan_hlen, len);
+        total += skb->len + vlan_hlen;
+        if (vlan_hlen) {
                 int copy, ret;
                 struct {
                         __be16 h_vlan_proto;
@@ -1311,8 +1319,6 @@ static ssize_t tun_put_user(struct tun_struct *tun,
                 veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
 
                 vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
-                len = min_t(int, skb->len + VLAN_HLEN, len);
-                total += VLAN_HLEN;
 
                 copy = min_t(int, vlan_offset, len);
                 ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);