5.4-stable review patch. If anyone has any objections, please let me know.
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From: Pablo Neira Ayuso pablo@netfilter.org
[ 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 pablo@netfilter.org Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 0409afe9a53d6..c2e649a4f1bf4 100644 --- a/drivers/net/gtp.c +++ b/drivers/net/gtp.c @@ -544,8 +544,9 @@ 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));