tuntap: correctly linearize skb when zerocopy is used

[~andy/linux] / drivers / net / tun.c

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 7eab5fcd064fa5bacc9ddc05557fc032bad327c0..5cdcf92eb310391c1684374d0c41a3147a55f762 100644 (file)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1042,7 +1042,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 {
        struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
        struct sk_buff *skb;
-       size_t len = total_len, align = NET_SKB_PAD;
+       size_t len = total_len, align = NET_SKB_PAD, linear;
        struct virtio_net_hdr gso = { 0 };
        int offset = 0;
        int copylen;
@@ -1106,10 +1106,13 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
                        copylen = gso.hdr_len;
                if (!copylen)
                        copylen = GOODCOPY_LEN;
-       } else
+               linear = copylen;
+       } else {
                copylen = len;
+               linear = gso.hdr_len;
+       }
 
-       skb = tun_alloc_skb(tfile, align, copylen, gso.hdr_len, noblock);
+       skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
        if (IS_ERR(skb)) {
                if (PTR_ERR(skb) != -EAGAIN)
                        tun->dev->stats.rx_dropped++;