unimore/kernel-hacking-2024-linux-steffo
unimore/kernel-hacking-2024-linux-steffo
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bareudp: Pull inner IP header in bareudp_udp_encap_recv().

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Bareudp reads the inner IP header to get the ECN value. Therefore, it
needs to ensure that it's part of the skb's linear data.

This is similar to the vxlan and geneve fixes for that same problem:
  * commit f778941913 ("vxlan: Pull inner IP header in vxlan_rcv().")
  * commit 1ca1ba465e ("geneve: make sure to pull inner header in
    geneve_rx()")

Fixes: 571912c69f ("net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/5205940067c40218a70fbb888080466b2fc288db.1726046181.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Guillaume Nault 2024-09-11 11:20:58 +02:00 committed by Jakub Kicinski
parent 5abfdfd402
commit 45fa29c851
1 changed files with 18 additions and 2 deletions
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20
drivers/net/bareudp.c
View file

@ -68,6 +68,7 @@ static int bareudp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
__be16 proto;
void *oiph;
int err;
int nh;
bareudp = rcu_dereference_sk_user_data(sk);
if (!bareudp)
@ -148,10 +149,25 @@ static int bareudp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
}
skb_dst_set(skb, &tun_dst->dst);
skb->dev = bareudp->dev;
oiph = skb_network_header(skb);
skb_reset_network_header(skb);
skb_reset_mac_header(skb);
/* Save offset of outer header relative to skb->head,
* because we are going to reset the network header to the inner header
* and might change skb->head.
*/
nh = skb_network_header(skb) - skb->head;
skb_reset_network_header(skb);
if (!pskb_inet_may_pull(skb)) {
DEV_STATS_INC(bareudp->dev, rx_length_errors);
DEV_STATS_INC(bareudp->dev, rx_errors);
goto drop;
}
/* Get the outer header. */
oiph = skb->head + nh;
if (!ipv6_mod_enabled() || family == AF_INET)
err = IP_ECN_decapsulate(oiph, skb);
else