From 2a3c3de660f96865f303fd25f1285f2ffbfd521d Mon Sep 17 00:00:00 2001 From: Zhiling Zou Date: Thu, 10 Sep 2026 13:08:32 +0300 Subject: [PATCH] ipvs: bound LBLCR and LBLC cache growth ip_vs_lblcr_new() and ip_vs_lblc_new() create cache entries for every previously unseen destination address. The table max_size only tells the periodic collector to reclaim entries after the cache has already exceeded the limit. It does not reclaim entries that the attacker continues to use. Reject new cache entries once either table reaches max_size * 3 / 2. The extra headroom lets the periodic collector catch up while the existing scheduler fallback continues to use the selected destination when cache creation fails. New traffic therefore stays serviceable without growing the tables further. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Reported-by: Vega Suggested-by: Julian Anastasov Signed-off-by: Zhiling Zou Acked-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipvs/ip_vs_lblc.c | 3 +++ net/netfilter/ipvs/ip_vs_lblcr.c | 3 +++ 2 files changed, 6 insertions(+) diff --git a/net/netfilter/ipvs/ip_vs_lblc.c b/net/netfilter/ipvs/ip_vs_lblc.c index a2b574904f13..55af77a56929 100644 --- a/net/netfilter/ipvs/ip_vs_lblc.c +++ b/net/netfilter/ipvs/ip_vs_lblc.c @@ -205,6 +205,9 @@ ip_vs_lblc_new(struct ip_vs_lblc_table *tbl, const union nf_inet_addr *daddr, ip_vs_lblc_del(en); atomic_dec(&tbl->entries); } + if (atomic_read(&tbl->entries) >= tbl->max_size * 3 / 2) + return NULL; + en = kmalloc_obj(*en, GFP_ATOMIC); if (!en) return NULL; diff --git a/net/netfilter/ipvs/ip_vs_lblcr.c b/net/netfilter/ipvs/ip_vs_lblcr.c index f53f05ceea36..858393b1d2d1 100644 --- a/net/netfilter/ipvs/ip_vs_lblcr.c +++ b/net/netfilter/ipvs/ip_vs_lblcr.c @@ -363,6 +363,9 @@ ip_vs_lblcr_new(struct ip_vs_lblcr_table *tbl, const union nf_inet_addr *daddr, en = ip_vs_lblcr_get(af, tbl, daddr); if (!en) { + if (atomic_read(&tbl->entries) >= tbl->max_size * 3 / 2) + return NULL; + en = kmalloc_obj(*en, GFP_ATOMIC); if (!en) return NULL;