From 722fc6bd7119128dca5c3c66bfa854a5901c5844 Mon Sep 17 00:00:00 2001 From: David Lamparter Date: Wed, 22 Jan 2025 11:19:04 +0100 Subject: [PATCH] lib: guard against padding garbage in ZAPI read When reading in a nexthop from ZAPI, only set the fields that actually have meaning. While it shouldn't happen to begin with, we can otherwise carry padding garbage into the unused leftover union bytes. Signed-off-by: David Lamparter (cherry picked from commit 4a0e1419a69d07496c7adfb744beecd00e1efef2) --- lib/zclient.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) diff --git a/lib/zclient.c b/lib/zclient.c index 8ec82ab7bb..9133393d46 100644 --- a/lib/zclient.c +++ b/lib/zclient.c @@ -1788,7 +1788,27 @@ struct nexthop *nexthop_from_zapi_nexthop(const struct zapi_nexthop *znh) n->type = znh->type; n->vrf_id = znh->vrf_id; n->ifindex = znh->ifindex; - n->gate = znh->gate; + + /* only copy values that have meaning - make sure "spare bytes" are + * left zeroed for hashing (look at _nexthop_hash_bytes) + */ + switch (znh->type) { + case NEXTHOP_TYPE_BLACKHOLE: + n->bh_type = znh->bh_type; + break; + case NEXTHOP_TYPE_IPV4: + case NEXTHOP_TYPE_IPV4_IFINDEX: + n->gate.ipv4 = znh->gate.ipv4; + break; + case NEXTHOP_TYPE_IPV6: + case NEXTHOP_TYPE_IPV6_IFINDEX: + n->gate.ipv6 = znh->gate.ipv6; + break; + case NEXTHOP_TYPE_IFINDEX: + /* nothing, ifindex is always copied */ + break; + } + n->srte_color = znh->srte_color; /* -- 2.39.5