From 643bb5dbaef7d01f9bcf2a495bef855e81fd5714 Mon Sep 17 00:00:00 2001 From: Alexander Mikhalitsyn Date: Mon, 6 May 2024 16:14:43 +0200 Subject: [PATCH] ipvs: add READ_ONCE barrier for ipvs->sysctl_amemthresh Cc: Julian Anastasov Cc: Simon Horman Cc: Pablo Neira Ayuso Cc: Jozsef Kadlecsik Cc: Florian Westphal Suggested-by: Julian Anastasov Signed-off-by: Alexander Mikhalitsyn Acked-by: Julian Anastasov Signed-off-by: David S. Miller --- net/netfilter/ipvs/ip_vs_ctl.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c index 50b5dbe40eb8..e122fa367b81 100644 --- a/net/netfilter/ipvs/ip_vs_ctl.c +++ b/net/netfilter/ipvs/ip_vs_ctl.c @@ -94,6 +94,7 @@ static void update_defense_level(struct netns_ipvs *ipvs) { struct sysinfo i; int availmem; + int amemthresh; int nomem; int to_change = -1; @@ -105,7 +106,8 @@ static void update_defense_level(struct netns_ipvs *ipvs) /* si_swapinfo(&i); */ /* availmem = availmem - (i.totalswap - i.freeswap); */ - nomem = (availmem < ipvs->sysctl_amemthresh); + amemthresh = max(READ_ONCE(ipvs->sysctl_amemthresh), 0); + nomem = (availmem < amemthresh); local_bh_disable(); @@ -145,9 +147,8 @@ static void update_defense_level(struct netns_ipvs *ipvs) break; case 1: if (nomem) { - ipvs->drop_rate = ipvs->drop_counter - = ipvs->sysctl_amemthresh / - (ipvs->sysctl_amemthresh-availmem); + ipvs->drop_counter = amemthresh / (amemthresh - availmem); + ipvs->drop_rate = ipvs->drop_counter; ipvs->sysctl_drop_packet = 2; } else { ipvs->drop_rate = 0; @@ -155,9 +156,8 @@ static void update_defense_level(struct netns_ipvs *ipvs) break; case 2: if (nomem) { - ipvs->drop_rate = ipvs->drop_counter - = ipvs->sysctl_amemthresh / - (ipvs->sysctl_amemthresh-availmem); + ipvs->drop_counter = amemthresh / (amemthresh - availmem); + ipvs->drop_rate = ipvs->drop_counter; } else { ipvs->drop_rate = 0; ipvs->sysctl_drop_packet = 1;