bgpd: EVPN crash because of incorrect nexthop for IPv6 prefix

RCA:
When we install IPv6 prefix imported from EVPN RT-5 in vrf, nexthop of the IPv6
route should be IPv4 mapped IPv6 address. In function
install_evpn_route_entry_in_vrf, we generate a new attribute with IPv4 mapped
IPv6 nexthop, but we use parent->attr while creating the actual route.
Thus, Ipv4 nexthop is assigned to this route.
Because of this incorrect nexthop, we observed a crash in function
update_ipv6nh_for_route_install.

Fix:
Pass the new attribute with Ipv4 mapped Ipv6 nexthop to
bgp_create_evpn_bgp_path_info

Signed-off-by: Ameya Dharkar <adharkar@vmware.com>

diff --git a/bgpd/bgp_evpn.c b/bgpd/bgp_evpn.c
index a93f81a8d855c34f72845340e176ff1f5e701991..76c7d93ad175b120afae4acb8d74cfcbdb720dbf 100644 (file)
--- a/bgpd/bgp_evpn.c
+++ b/bgpd/bgp_evpn.c
@@ -2526,13 +2526,13 @@ static int handle_tunnel_ip_change(struct bgp *bgp, struct bgpevpn *vpn,
 
 static struct bgp_path_info *
 bgp_create_evpn_bgp_path_info(struct bgp_path_info *parent_pi,
-                             struct bgp_node *rn)
+                             struct bgp_node *rn, struct attr *attr)
 {
        struct attr *attr_new;
        struct bgp_path_info *pi;
 
        /* Add (or update) attribute to hash. */
-       attr_new = bgp_attr_intern(parent_pi->attr);
+       attr_new = bgp_attr_intern(attr);
 
        /* Create new route with its attribute. */
        pi = info_make(parent_pi->type, BGP_ROUTE_IMPORTED, 0, parent_pi->peer,
@@ -2675,7 +2675,7 @@ static int install_evpn_route_entry_in_vrf(struct bgp *bgp_vrf,
                        break;
 
        if (!pi)
-               pi = bgp_create_evpn_bgp_path_info(parent_pi, rn);
+               pi = bgp_create_evpn_bgp_path_info(parent_pi, rn, &attr);
        else {
                if (attrhash_cmp(pi->attr, &attr)
                    && !CHECK_FLAG(pi->flags, BGP_PATH_REMOVED)) {
@@ -2744,7 +2744,8 @@ static int install_evpn_route_entry(struct bgp *bgp, struct bgpevpn *vpn,
 
        if (!pi) {
                /* Create an info */
-               (void)bgp_create_evpn_bgp_path_info(parent_pi, rn);
+               (void)bgp_create_evpn_bgp_path_info(parent_pi, rn,
+                                                   parent_pi->attr);
        } else {
                if (attrhash_cmp(pi->attr, parent_pi->attr)
                    && !CHECK_FLAG(pi->flags, BGP_PATH_REMOVED)) {