From: Sabrina Dubroca <sd@queasysnail.net> stable inclusion from linux-4.19.151 commit a01cb66b26a39062a3cccc6e77b3b53a737c254e -------------------------------- commit 45a36a18d01907710bad5258d81f76c18882ad88 upstream. xfrm interfaces currently test for !skb->ignore_df when deciding whether to update the pmtu on the skb's dst. Because of this, no pmtu exception is created when we do something like: ping -s 1438 <dest> By dropping this check, the pmtu exception will be created and the next ping attempt will work. Fixes: f203b76d7809 ("xfrm: Add virtual xfrm interfaces") Reported-by: Xiumei Mu <xmu@redhat.com> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: Aichun Li <liaichun@huawei.com> Reviewed-by: wangxiaopeng <wangxiaopeng7@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- net/xfrm/xfrm_interface.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c index bd24359a9136..0079e5922067 100644 --- a/net/xfrm/xfrm_interface.c +++ b/net/xfrm/xfrm_interface.c @@ -293,7 +293,7 @@ xfrmi_xmit2(struct sk_buff *skb, struct net_device *dev, struct flowi *fl) } mtu = dst_mtu(dst); - if (!skb->ignore_df && skb->len > mtu) { + if (skb->len > mtu) { skb_dst_update_pmtu_no_confirm(skb, mtu); if (skb->protocol == htons(ETH_P_IPV6)) { -- 2.25.1