Some dst_ops (e.g. md_dst_ops)) doesn't set this handler. It may result to:
"BUG: unable to handle kernel NULL pointer dereference at (null)"
Let's add a helper to check if update_pmtu is available before calling it.
Fixes: 52a589d51f10 ("geneve: update skb dst pmtu on tx path")
Fixes: a93bf0ff4490 ("vxlan: update skb dst pmtu on tx path")
CC: Roman Kapl <c...@rkapl.cz>
CC: Xin Long <lucien....@gmail.com>
Signed-off-by: Nicolas Dichtel <nicolas.dich...@6wind.com>
---
drivers/infiniband/ulp/ipoib/ipoib_cm.c | 3 +--
drivers/net/geneve.c | 4 ++--
drivers/net/vxlan.c | 6 ++----
include/net/dst.h | 8 ++++++++
net/ipv4/ip_tunnel.c | 3 +--
net/ipv4/ip_vti.c | 2 +-
net/ipv6/ip6_tunnel.c | 6 ++----
net/ipv6/ip6_vti.c | 2 +-
net/ipv6/sit.c | 4 ++--
9 files changed, 20 insertions(+), 18 deletions(-)
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
index 2c13123bfd69..71ea9e26666c 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
@@ -1456,8 +1456,7 @@ void ipoib_cm_skb_too_long(struct net_device *dev, struct
sk_buff *skb,
struct ipoib_dev_priv *priv = ipoib_priv(dev);
int e = skb_queue_empty(&priv->cm.skb_queue);
- if (skb_dst(skb))
- skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
+ skb_dst_update_pmtu(skb, mtu);
skb_queue_tail(&priv->cm.skb_queue, skb);
if (e)
diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 0a48b3073d3d..64fda2e1040e 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -829,7 +829,7 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct
net_device *dev,
int mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr) -
GENEVE_BASE_HLEN - info->options_len - 14;
- skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
+ skb_dst_update_pmtu(skb, mtu);
}
sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
@@ -875,7 +875,7 @@ static int geneve6_xmit_skb(struct sk_buff *skb, struct
net_device *dev,
int mtu = dst_mtu(dst) - sizeof(struct ipv6hdr) -
GENEVE_BASE_HLEN - info->options_len - 14;
- skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
+ skb_dst_update_pmtu(skb, mtu);
}
sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 31f4b7911ef8..c3e34e3c82a7 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -2158,8 +2158,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct
net_device *dev,
if (skb_dst(skb)) {
int mtu = dst_mtu(ndst) - VXLAN_HEADROOM;
- skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL,
- skb, mtu);
+ skb_dst_update_pmtu(skb, mtu);
}
tos = ip_tunnel_ecn_encap(tos, old_iph, skb);
@@ -2200,8 +2199,7 @@ static void vxlan_xmit_one(struct sk_buff *skb, struct
net_device *dev,
if (skb_dst(skb)) {
int mtu = dst_mtu(ndst) - VXLAN6_HEADROOM;
- skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL,
- skb, mtu);
+ skb_dst_update_pmtu(skb, mtu);
}
tos = ip_tunnel_ecn_encap(tos, old_iph, skb);
diff --git a/include/net/dst.h b/include/net/dst.h
index b091fd536098..6216edb58393 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -521,4 +521,12 @@ static inline struct xfrm_state *dst_xfrm(const struct
dst_entry *dst)
}
#endif
+static inline void skb_dst_update_pmtu(struct sk_buff *skb, u32 mtu)
+{
+ struct dst_entry *dst = skb_dst(skb);
+
+ if (dst && dst->ops->update_pmtu)
+ skb_dst(skb)->ops->update_pmtu(dst, NULL, skb, mtu);
+}
+
#endif /* _NET_DST_H */
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 5ddb1cb52bd4..6d21068f9b55 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -520,8 +520,7 @@ static int tnl_update_pmtu(struct net_device *dev, struct
sk_buff *skb,
else
mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
- if (skb_dst(skb))
- skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
+ skb_dst_update_pmtu(skb, mtu);
if (skb->protocol == htons(ETH_P_IP)) {
if (!skb_is_gso(skb) &&
diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c
index 949f432a5f04..51b1669334fe 100644
--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -200,7 +200,7 @@ static netdev_tx_t vti_xmit(struct sk_buff *skb, struct
net_device *dev,
mtu = dst_mtu(dst);
if (skb->len > mtu) {
- skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
+ skb_dst_update_pmtu(skb, mtu);
if (skb->protocol == htons(ETH_P_IP)) {
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
htonl(mtu));
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 9a7cf355bc8c..1ee5584c3555 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -642,8 +642,7 @@ ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
if (rel_info > dst_mtu(skb_dst(skb2)))
goto out;
- skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2,
- rel_info);
+ skb_dst_update_pmtu(skb2, rel_info);
}
icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
@@ -1131,8 +1130,7 @@ int ip6_tnl_xmit(struct sk_buff *skb, struct net_device
*dev, __u8 dsfield,
mtu = 576;
}
- if (skb_dst(skb) && !t->parms.collect_md)
- skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
+ skb_dst_update_pmtu(skb, mtu);
if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
*pmtu = mtu;
err = -EMSGSIZE;
diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index dbb74f3c57a7..8c184f84f353 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -483,7 +483,7 @@ vti6_xmit(struct sk_buff *skb, struct net_device *dev,
struct flowi *fl)
mtu = dst_mtu(dst);
if (!skb->ignore_df && skb->len > mtu) {
- skb_dst(skb)->ops->update_pmtu(dst, NULL, skb, mtu);
+ skb_dst_update_pmtu(skb, mtu);
if (skb->protocol == htons(ETH_P_IPV6)) {
if (mtu < IPV6_MIN_MTU)
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index d7dc23c1b2ca..3873d3877135 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -934,8 +934,8 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
df = 0;
}
- if (tunnel->parms.iph.daddr && skb_dst(skb))
- skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb,
mtu);
+ if (tunnel->parms.iph.daddr)
+ skb_dst_update_pmtu(skb, mtu);
if (skb->len > mtu && !skb_is_gso(skb)) {
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
--
2.15.1
