From 9c20cd200b40236ce2a24bc4d91846226de696ae Mon Sep 17 00:00:00 2001 From: Rajasekar Raja Date: Tue, 10 Dec 2024 13:45:02 -0800 Subject: [PATCH] bgpd: Fix bgp core with a possible Intf delete Although trigger unknown, based on the backtrace in one of the internal testing, we do see some delete in the Intf where we can have the peer ifp pointer null and we try to dereference it while trying to install the route leading to a crash Skip updating the ifindex in such cases and since the nexthop is not properly updated, BGP skips sending it to zebra. BackTrace: 0 0x00007faef05e7ebc in ?? () from /lib/x86_64-linux-gnu/libc.so.6 1 0x00007faef0598fb2 in raise () from /lib/x86_64-linux-gnu/libc.so.6 2 0x00007faef09900dc in core_handler (signo=11, siginfo=0x7ffdde8cb4b0, context=) at lib/sigevent.c:274 3 4 0x00005560aad4b7d8 in update_ipv6nh_for_route_install (api_nh=0x7ffdde8cbe94, is_evpn=false, best_pi=0x5560b21187d0, pi=0x5560b21187d0, ifindex=0, nexthop=0x5560b03cb0dc, nh_bgp=0x5560ace04df0, nh_othervrf=0) at bgpd/bgp_zebra.c:1273 5 bgp_zebra_announce_actual (dest=dest@entry=0x5560afcfa950, info=0x5560b21187d0, bgp=0x5560ace04df0) at bgpd/bgp_zebra.c:1521 6 0x00005560aad4bc85 in bgp_handle_route_announcements_to_zebra (e=) at bgpd/bgp_zebra.c:1896 7 0x00007faef09a1c0d in thread_call (thread=thread@entry=0x7ffdde8d7580) at lib/thread.c:2008 8 0x00007faef095a598 in frr_run (master=0x5560ac7e5190) at lib/libfrr.c:1223 9 0x00005560aac65db6 in main (argc=, argv=) at bgpd/bgp_main.c:557 (gdb) f 4 4 0x00005560aad4b7d8 in update_ipv6nh_for_route_install (api_nh=0x7ffdde8cbe94, is_evpn=false, best_pi=0x5560b21187d0, pi=0x5560b21187d0, ifindex=0, nexthop=0x5560b03cb0dc, nh_bgp=0x5560ace04df0, nh_othervrf=0) at bgpd/bgp_zebra.c:1273 1273 in bgpd/bgp_zebra.c (gdb) p pi->peer->ifp $26 = (struct interface *) 0x0 Ticket :#4203904 Signed-off-by: Rajasekar Raja --- bgpd/bgp_zebra.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/bgpd/bgp_zebra.c b/bgpd/bgp_zebra.c index ebd20c5bfece..a64eb3559170 100644 --- a/bgpd/bgp_zebra.c +++ b/bgpd/bgp_zebra.c @@ -1166,9 +1166,10 @@ static bool update_ipv6nh_for_route_install(int nh_othervrf, struct bgp *nh_bgp, ifindex = pi->peer->nexthop.ifp->ifindex; if (!ifindex) { - if (pi->peer->conf_if) - ifindex = pi->peer->ifp->ifindex; - else if (pi->peer->ifname) + if (pi->peer->conf_if) { + if (pi->peer->ifp) + ifindex = pi->peer->ifp->ifindex; + } else if (pi->peer->ifname) ifindex = ifname2ifindex( pi->peer->ifname, pi->peer->bgp->vrf_id);