From: Eyal Birger <eyal.birger@gmail.com> mainline inclusion from mainline-5.12-rc7 commit 4c38255892c06b9de2fb3bf6aea63f4ebdff3d11 category: bugfix issue: #I3ZXZF CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ------------------------------------------------- Frag needed should only be sent if the header enables DF. This fix allows IPv4 packets larger than MTU to pass the vti6 interface and be fragmented after encapsulation, aligning behavior with non-vti6 xfrm. Fixes: ccd740cbc6e0 ("vti6: Add pmtu handling to vti6_xmit.") Signed-off-by: Eyal Birger <eyal.birger@gmail.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Conflicts: net/ipv6/ip6_vti.c Signed-off-by: Ziyang Xuan <xuanziyang2@huawei.com> Reviewed-by: Yue Haibing <yuehaibing@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.com> Signed-off-by: Yu Changchun <yuchangchun1@huawei.com> --- net/ipv6/ip6_vti.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c index 23aeeb46f99f..2c30f142ac51 100644 --- a/net/ipv6/ip6_vti.c +++ b/net/ipv6/ip6_vti.c @@ -492,7 +492,7 @@ vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl) } if (dst->flags & DST_XFRM_QUEUE) - goto queued; + goto xmit; x = dst->xfrm; if (!vti6_state_check(x, &t->parms.raddr, &t->parms.laddr)) @@ -521,6 +521,8 @@ vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl) icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); } else { + if (!(ip_hdr(skb)->frag_off & htons(IP_DF))) + goto xmit; icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); } @@ -529,7 +531,7 @@ vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl) goto tx_err_dst_release; } -queued: +xmit: skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev))); skb_dst_set(skb, dst); skb->dev = skb_dst(skb)->dev; -- 2.22.0