From d5c175f4cea65bcb7cadc715390fae690bfe842b Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 22 Oct 2023 22:25:18 +0200 Subject: [PATCH] gtp: fix fragmentation needed check with gso [ Upstream commit 4530e5b8e2dad63dcad2206232dd86e4b1489b6c ] 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 Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- drivers/net/gtp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c index a3878aef0ea4..69bbc868b947 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -543,8 +543,9 @@ static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev, 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));