From: Cong Wang <cong.wang@xxxxxxxxxxxxx>
[ Upstream commit c88f8d5cd95fd039cff95d682b8e71100c001df0 ]
When a tunnel device is bound with the underlying device, its
dev->needed_headroom needs to be updated properly. IPv4 tunnels
already do the same in ip_tunnel_bind_dev(). Otherwise we may
not have enough header room for skb, especially after commit
b17f709a2401 ("gue: TX support for using remote checksum offload option").
Fixes: 32b8a8e59c9c ("sit: add IPv4 over IPv4 support")
Reported-by: Palash Oswal <oswalpalash@xxxxxxxxx>
Link: https://lore.kernel.org/netdev/CAGyP=7fDcSPKu6nttbGwt7RXzE3uyYxLjCSE97J64pRxJP8jPA@xxxxxxxxxxxxxx/
Cc: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: Cong Wang <cong.wang@xxxxxxxxxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reviewed-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/ipv6/sit.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 70d81bba50939..3ffb6a5b1f82a 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -1095,12 +1095,13 @@ static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
static void ipip6_tunnel_bind_dev(struct net_device *dev)
{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ int t_hlen = tunnel->hlen + sizeof(struct iphdr);
struct net_device *tdev = NULL;
- struct ip_tunnel *tunnel;
+ int hlen = LL_MAX_HEADER;
const struct iphdr *iph;
struct flowi4 fl4;
- tunnel = netdev_priv(dev);
iph = &tunnel->parms.iph;
if (iph->daddr) {
@@ -1123,14 +1124,15 @@ static void ipip6_tunnel_bind_dev(struct net_device *dev)
tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
if (tdev && !netif_is_l3_master(tdev)) {
- int t_hlen = tunnel->hlen + sizeof(struct iphdr);
int mtu;
mtu = tdev->mtu - t_hlen;
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
WRITE_ONCE(dev->mtu, mtu);
+ hlen = tdev->hard_header_len + tdev->needed_headroom;
}
+ dev->needed_headroom = t_hlen + hlen;
}
static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p,
--
2.39.2
