This is a note to let you know that I've just added the patch titled net: sched: act_mirred: drop dst for the direction from egress to ingress to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-sched-act_mirred-drop-dst-for-the-direction-from.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit d4d92e545359153901471eab5657077e54c17167 Author: Xin Long <lucien.xin@xxxxxxxxx> Date: Fri Nov 12 11:33:11 2021 -0500 net: sched: act_mirred: drop dst for the direction from egress to ingress [ Upstream commit f799ada6bf2397c351220088b9b0980125c77280 ] Without dropping dst, the packets sent from local mirred/redirected to ingress will may still use the old dst. ip_rcv() will drop it as the old dst is for output and its .input is dst_discard. This patch is to fix by also dropping dst for those packets that are mirred or redirected from egress to ingress in act_mirred. Note that we don't drop it for the direction change from ingress to egress, as on which there might be a user case attaching a metadata dst by act_tunnel_key that would be used later. Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct") Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx> Acked-by: Cong Wang <cong.wang@xxxxxxxxxxxxx> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c index e3ff884a48c56..b87d2a1ee0b16 100644 --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -19,6 +19,7 @@ #include <linux/if_arp.h> #include <net/net_namespace.h> #include <net/netlink.h> +#include <net/dst.h> #include <net/pkt_sched.h> #include <net/pkt_cls.h> #include <linux/tc_act/tc_mirred.h> @@ -218,6 +219,7 @@ static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a, bool want_ingress; bool is_redirect; bool expects_nh; + bool at_ingress; int m_eaction; int mac_len; bool at_nh; @@ -253,7 +255,8 @@ static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a, * ingress - that covers the TC S/W datapath. */ is_redirect = tcf_mirred_is_act_redirect(m_eaction); - use_reinsert = skb_at_tc_ingress(skb) && is_redirect && + at_ingress = skb_at_tc_ingress(skb); + use_reinsert = at_ingress && is_redirect && tcf_mirred_can_reinsert(retval); if (!use_reinsert) { skb2 = skb_clone(skb, GFP_ATOMIC); @@ -261,10 +264,12 @@ static int tcf_mirred_act(struct sk_buff *skb, const struct tc_action *a, goto out; } + want_ingress = tcf_mirred_act_wants_ingress(m_eaction); + /* All mirred/redirected skbs should clear previous ct info */ nf_reset_ct(skb2); - - want_ingress = tcf_mirred_act_wants_ingress(m_eaction); + if (want_ingress && !at_ingress) /* drop dst for egress -> ingress */ + skb_dst_drop(skb2); expects_nh = want_ingress || !m_mac_header_xmit; at_nh = skb->data == skb_network_header(skb);