1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 2cd10b26b650..bfabe180053e 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1170,9 +1170,11 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
         }
 
         if (tun->flags & IFF_VNET_HDR) {
-                if (len < tun->vnet_hdr_sz)
+                int vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
+
+                if (len < vnet_hdr_sz)
                         return -EINVAL;
-                len -= tun->vnet_hdr_sz;
+                len -= vnet_hdr_sz;
 
                 if (!copy_from_iter_full(&gso, sizeof(gso), from))
                         return -EFAULT;
@@ -1183,7 +1185,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
 
                 if (tun16_to_cpu(tun, gso.hdr_len) > len)
                         return -EINVAL;
-                iov_iter_advance(from, tun->vnet_hdr_sz - sizeof(gso));
+                iov_iter_advance(from, vnet_hdr_sz - sizeof(gso));
         }
 
         if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
@@ -1335,7 +1337,7 @@ static ssize_t tun_put_user(struct tun_struct *tun,
                 vlan_hlen = VLAN_HLEN;
 
         if (tun->flags & IFF_VNET_HDR)
-                vnet_hdr_sz = tun->vnet_hdr_sz;
+                vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz);
 
         total = skb->len + vlan_hlen + vnet_hdr_sz;