4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Pablo Neira Ayuso pablo@netfilter.org
commit 4530e5b8e2dad63dcad2206232dd86e4b1489b6c upstream.
Call skb_gso_validate_network_len() to check if packet is over PMTU.
Fixes: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/gtp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -548,8 +548,9 @@ static int gtp_build_skb_ip4(struct sk_b
rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu, false);
- if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) && - mtu < ntohs(iph->tot_len)) { + if (iph->frag_off & htons(IP_DF) && + ((!skb_is_gso(skb) && skb->len > mtu) || + (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu)))) { netdev_dbg(dev, "packet too big, fragmentation needed\n"); icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));