Hello, I am proposing a fix for a segfault encountered in bird6, in the nexthop_compare_node function.
This patch adds checks for validating that x->iface and y->iface are not null before accessing their index field. I initially proposed a fix on calico's bird fork : https://github.com/projectcalico/bird/pull/117 but I was asked to propose it to the official repo. Please find the full patch attached. Best regards, Mathieu.
From e66d69d4fa9cb10362c5f4ba7e7d3c1cd4005973 Mon Sep 17 00:00:00 2001 From: Mathieu <[email protected]> Date: Mon, 16 Feb 2026 14:25:14 +0100 Subject: [PATCH] Add null checks for iface before accessing index in mpnh_compare_node --- nest/rt-attr.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/nest/rt-attr.c b/nest/rt-attr.c index e10e1ecb..1fb93f8e 100644 --- a/nest/rt-attr.c +++ b/nest/rt-attr.c @@ -255,6 +255,12 @@ nexthop_compare_node(const struct nexthop *x, const struct nexthop *y) return r; } + if (!x->iface) + return 1; + + if (!y->iface) + return -1; + return ((int) x->iface->index) - ((int) y->iface->index); } -- 2.34.1
