From df6c9d4656d0793cb2198b3d5f2d36e283486e55 Mon Sep 17 00:00:00 2001 From: Jesper Dangaard Brouer Date: Fri, 8 Jan 2021 12:44:33 +0100 Subject: [PATCH] netfilter: conntrack: fix reading nf_conntrack_buckets commit f6351c3f1c27c80535d76cac2299aec44c36291e upstream. The old way of changing the conntrack hashsize runtime was through changing the module param via file /sys/module/nf_conntrack/parameters/hashsize. This was extended to sysctl change in commit 3183ab8997a4 ("netfilter: conntrack: allow increasing bucket size via sysctl too"). The commit introduced second "user" variable nf_conntrack_htable_size_user which shadow actual variable nf_conntrack_htable_size. When hashsize is changed via module param this "user" variable isn't updated. This results in sysctl net/netfilter/nf_conntrack_buckets shows the wrong value when users update via the old way. This patch fix the issue by always updating "user" variable when reading the proc file. This will take care of changes to the actual variable without sysctl need to be aware. Fixes: 3183ab8997a4 ("netfilter: conntrack: allow increasing bucket size via sysctl too") Reported-by: Yoel Caspersen Signed-off-by: Jesper Dangaard Brouer Acked-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman --- net/netfilter/nf_conntrack_standalone.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c index 5f446cd9f3fd4..0dbd17137dee6 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -458,6 +458,9 @@ nf_conntrack_hash_sysctl(struct ctl_table *table, int write, { int ret; + /* module_param hashsize could have changed value */ + nf_conntrack_htable_size_user = nf_conntrack_htable_size; + ret = proc_dointvec(table, write, buffer, lenp, ppos); if (ret < 0 || !write) return ret; -- 2.47.2