[PATCH] Signed-off-by: Peter Kosyh <p.kosyh@gmail.com>

vrf_process_v4_outbound() and vrf_process_v6_outbound() do routing
using ip/ipv6 addresses, but don't make sure the header is available in
skb->data[] (skb_headlen() is less then header size).

The situation may occures while forwarding from MPLS layer to vrf, for
example.

So, this patch adds pskb_may_pull() calls in is_ip_tx_frame(), just before
call to vrf_process_... functions.

Signed-off-by: Peter Kosyh <redacted>
---
 drivers/net/vrf.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 54edf8956a25..d552f29a58d1 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c

@@ -292,13 +292,16 @@ static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
 {
 	switch (skb->protocol) {
 	case htons(ETH_P_IP):
+		if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr))
+			break;
 		return vrf_process_v4_outbound(skb, dev);
 	case htons(ETH_P_IPV6):
+		if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr))
+			break;
 		return vrf_process_v6_outbound(skb, dev);
-	default:
-		vrf_tx_error(dev, skb);
-		return NET_XMIT_DROP;
 	}
+	vrf_tx_error(dev, skb);
+	return NET_XMIT_DROP;
 }
 
 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)

-- 
2.11.0

your subject line needs a proper Subject - a one-line summary of the
change starting with 'vrf:'. See examples from 'git log drivers/net/vrf.c'


On 7/18/19 3:41 AM, Peter Kosyh wrote:

vrf_process_v4_outbound() and vrf_process_v6_outbound() do routing
using ip/ipv6 addresses, but don't make sure the header is available in
skb->data[] (skb_headlen() is less then header size).

The situation may occures while forwarding from MPLS layer to vrf, for
example.

so the use case is a label pop with the nexthop as the VRF device?

that check goes in vrf_process_v4_outbound.

 		return vrf_process_v4_outbound(skb, dev);
 	case htons(ETH_P_IPV6):
+		if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr))
+			break;

that check goes in vrf_process_v6_outbound

leave this higher level sorter untouched.

 		return vrf_process_v6_outbound(skb, dev);
-	default:
-		vrf_tx_error(dev, skb);
-		return NET_XMIT_DROP;
 	}
+	vrf_tx_error(dev, skb);
+	return NET_XMIT_DROP;
 }
 
 static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)

From: David Ahern <redacted>
Date: Thu, 18 Jul 2019 08:02:45 -0600

your subject line needs a proper Subject - a one-line summary of the
change starting with 'vrf:'. See examples from 'git log drivers/net/vrf.c'

Indeed, you really need to fix this even for your second submission as it
had the same exact problem.

vrf_process_v4_outbound() and vrf_process_v6_outbound() do routing
using ip/ipv6 addresses, but don't make sure the header is available
in skb->data[] (skb_headlen() is less then header size).

Case:

1) igb driver from intel.
2) Packet size is greater then 255.
3) MPLS forwards to VRF device.

So, patch adds pskb_may_pull() calls in vrf_process_v4/v6_outbound()
functions.

Signed-off-by: Peter Kosyh <redacted>
---
 drivers/net/vrf.c | 58 +++++++++++++++++++++++++++++++++----------------------
 1 file changed, 35 insertions(+), 23 deletions(-)

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 54edf8956a25..6e84328bdd40 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c

@@ -165,23 +165,29 @@ static int vrf_ip6_local_out(struct net *net, struct sock *sk,
 static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
 					   struct net_device *dev)
 {
-	const struct ipv6hdr *iph = ipv6_hdr(skb);
+	const struct ipv6hdr *iph;
 	struct net *net = dev_net(skb->dev);
-	struct flowi6 fl6 = {
-		/* needed to match OIF rule */
-		.flowi6_oif = dev->ifindex,
-		.flowi6_iif = LOOPBACK_IFINDEX,
-		.daddr = iph->daddr,
-		.saddr = iph->saddr,
-		.flowlabel = ip6_flowinfo(iph),
-		.flowi6_mark = skb->mark,
-		.flowi6_proto = iph->nexthdr,
-		.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF,
-	};
+	struct flowi6 fl6;
 	int ret = NET_XMIT_DROP;
 	struct dst_entry *dst;
 	struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
 
+	if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
+		goto err;
+
+	iph = ipv6_hdr(skb);
+
+	memset(&fl6, 0, sizeof(fl6));
+	/* needed to match OIF rule */
+	fl6.flowi6_oif = dev->ifindex;
+	fl6.flowi6_iif = LOOPBACK_IFINDEX;
+	fl6.daddr = iph->daddr;
+	fl6.saddr = iph->saddr;
+	fl6.flowlabel = ip6_flowinfo(iph);
+	fl6.flowi6_mark = skb->mark;
+	fl6.flowi6_proto = iph->nexthdr;
+	fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF;
+
 	dst = ip6_route_output(net, NULL, &fl6);
 	if (dst == dst_null)
 		goto err;

@@ -237,21 +243,27 @@ static int vrf_ip_local_out(struct net *net, struct sock *sk,
 static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
 					   struct net_device *vrf_dev)
 {
-	struct iphdr *ip4h = ip_hdr(skb);
+	struct iphdr *ip4h;
 	int ret = NET_XMIT_DROP;
-	struct flowi4 fl4 = {
-		/* needed to match OIF rule */
-		.flowi4_oif = vrf_dev->ifindex,
-		.flowi4_iif = LOOPBACK_IFINDEX,
-		.flowi4_tos = RT_TOS(ip4h->tos),
-		.flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF,
-		.flowi4_proto = ip4h->protocol,
-		.daddr = ip4h->daddr,
-		.saddr = ip4h->saddr,
-	};
+	struct flowi4 fl4;
 	struct net *net = dev_net(vrf_dev);
 	struct rtable *rt;
 
+	if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
+		goto err;
+
+	ip4h = ip_hdr(skb);
+
+	memset(&fl4, 0, sizeof(fl4));
+	/* needed to match OIF rule */
+	fl4.flowi4_oif = vrf_dev->ifindex;
+	fl4.flowi4_iif = LOOPBACK_IFINDEX;
+	fl4.flowi4_tos = RT_TOS(ip4h->tos);
+	fl4.flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_SKIP_NH_OIF;
+	fl4.flowi4_proto = ip4h->protocol;
+	fl4.daddr = ip4h->daddr;
+	fl4.saddr = ip4h->saddr;
+
 	rt = ip_route_output_flow(net, &fl4, NULL);
 	if (IS_ERR(rt))
 		goto err;

-- 
2.11.0

On 7/19/19 2:11 AM, Peter Kosyh wrote:

vrf_process_v4_outbound() and vrf_process_v6_outbound() do routing
using ip/ipv6 addresses, but don't make sure the header is available
in skb->data[] (skb_headlen() is less then header size).

Case:

1) igb driver from intel.
2) Packet size is greater then 255.
3) MPLS forwards to VRF device.

So, patch adds pskb_may_pull() calls in vrf_process_v4/v6_outbound()
functions.

Signed-off-by: Peter Kosyh <redacted>
---
 drivers/net/vrf.c | 58 +++++++++++++++++++++++++++++++++----------------------
 1 file changed, 35 insertions(+), 23 deletions(-)

Reviewed-by: David Ahern <redacted>

From: Peter Kosyh <redacted>
Date: Fri, 19 Jul 2019 11:11:47 +0300

vrf_process_v4_outbound() and vrf_process_v6_outbound() do routing
using ip/ipv6 addresses, but don't make sure the header is available
in skb->data[] (skb_headlen() is less then header size).

Case:

1) igb driver from intel.
2) Packet size is greater then 255.
3) MPLS forwards to VRF device.

So, patch adds pskb_may_pull() calls in vrf_process_v4/v6_outbound()
functions.

Signed-off-by: Peter Kosyh <redacted>

Applied and queued up for -stable, thanks.