From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [PATCH net-next] tun: fix issues of iovec iterators using in tun_put_user() Date: Thu, 13 Nov 2014 16:54:14 +0800 Message-ID: <1415868854-4913-1-git-send-email-jasowang@redhat.com> Cc: mst@redhat.com, Herbert Xu To: davem@davemloft.net, jasowang@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org This patch fixes two issues after using iovec iterators: - vlan_offset should be initialized to zero, otherwise unexpected offset will be used in skb_copy_datagram_iter() - advance iovec iterator when vnet_hdr_sz is greater than sizeof(gso), this is the case when mergeable rx buffer were enabled for a virt guest. Fixes e0b46d0ee9c240c7430a47e9b0365674d4a04522 ("tun: Use iovec iterators") Cc: Herbert Xu Signed-off-by: Jason Wang --- drivers/net/tun.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 2ff769b..e3fa65a 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1235,7 +1235,7 @@ static ssize_t tun_put_user(struct tun_struct *tun, { struct tun_pi pi = { 0, skb->protocol }; ssize_t total; - int vlan_offset; + int vlan_offset = 0; int vlan_hlen = 0; int vnet_hdr_sz = 0; @@ -1304,6 +1304,8 @@ static ssize_t tun_put_user(struct tun_struct *tun, if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso)) return -EFAULT; + + iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso)); } if (vlan_hlen) { -- 1.9.1