[PATCH 5.11 566/601] net: geneve: modify IP header check in geneve6_xmit_skb and geneve_xmit_skb

Greg Kroah-Hartman
2021-05-12T17:57:56Z

From: Phillip Potter <phil@philpotter.co.uk>

[ Upstream commit d13f048dd40e8577260cd43faea8ec9b77520197 ]

Modify the header size check in geneve6_xmit_skb and geneve_xmit_skb
to use pskb_inet_may_pull rather than pskb_network_may_pull. This fixes
two kernel selftest failures introduced by the commit introducing the
checks:
IPv4 over geneve6: PMTU exceptions
IPv4 over geneve6: PMTU exceptions - nexthop objects

It does this by correctly accounting for the fact that IPv4 packets may
transit over geneve IPv6 tunnels (and vice versa), and still fixes the
uninit-value bug fixed by the original commit.

Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: 6628ddfec758 ("net: geneve: check skb is large enough for IPv4/IPv6 header")
Suggested-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Acked-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/geneve.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/geneve.c b/drivers/net/geneve.c
index 040edc6fc560..0d8eb4a1dc2f 100644
--- a/drivers/net/geneve.c
+++ b/drivers/net/geneve.c
@@ -891,7 +891,7 @@ static int geneve_xmit_skb(struct sk_buff *skb, struct net_device *dev,
__be16 sport;
int err;

- if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))
+ if (!pskb_inet_may_pull(skb))
return -EINVAL;

sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
@@ -988,7 +988,7 @@ static int geneve6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
__be16 sport;
int err;

- if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
+ if (!pskb_inet_may_pull(skb))
return -EINVAL;

sport = udp_flow_src_port(geneve->net, skb, 1, USHRT_MAX, true);
--
2.30.2