From adc8df12d91a2b8350b0cd4c7fec3e8546c9d1f8 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 22 Oct 2023 22:25:17 +0200 Subject: [PATCH 1/2] gtp: uapi: fix GTPA_MAX Subtract one to __GTPA_MAX, otherwise GTPA_MAX is off by 2. 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 --- include/uapi/linux/gtp.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/uapi/linux/gtp.h b/include/uapi/linux/gtp.h index 2f61298a7b779..3dcdb9e33cba2 100644 --- a/include/uapi/linux/gtp.h +++ b/include/uapi/linux/gtp.h @@ -33,6 +33,6 @@ enum gtp_attrs { GTPA_PAD, __GTPA_MAX, }; -#define GTPA_MAX (__GTPA_MAX + 1) +#define GTPA_MAX (__GTPA_MAX - 1) #endif /* _UAPI_LINUX_GTP_H_ */ From 4530e5b8e2dad63dcad2206232dd86e4b1489b6c Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 22 Oct 2023 22:25:18 +0200 Subject: [PATCH 2/2] gtp: fix fragmentation needed check with gso 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 --- 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 144ec626230d6..b22596b18ee8c 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -872,8 +872,9 @@ static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev, skb_dst_update_pmtu_no_confirm(skb, mtu); - 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));