From 5191d50192ec1281e51cbcb5248cb2667ff4d896 Mon Sep 17 00:00:00 2001 From: Jan Engelhardt Date: Mon, 4 Jan 2010 16:27:25 +0100 Subject: [PATCH] netfilter: xtables: do not grab random bytes at __init "It is deliberately not done in the init function, since we might not have sufficient random while booting." Signed-off-by: Jan Engelhardt Signed-off-by: Patrick McHardy --- net/netfilter/xt_NFQUEUE.c | 6 +++++- net/netfilter/xt_RATEEST.c | 7 ++++++- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/net/netfilter/xt_NFQUEUE.c b/net/netfilter/xt_NFQUEUE.c index f28f6a5fc02d..12dcd7007c3e 100644 --- a/net/netfilter/xt_NFQUEUE.c +++ b/net/netfilter/xt_NFQUEUE.c @@ -28,6 +28,7 @@ MODULE_ALIAS("ip6t_NFQUEUE"); MODULE_ALIAS("arpt_NFQUEUE"); static u32 jhash_initval __read_mostly; +static bool rnd_inited __read_mostly; static unsigned int nfqueue_tg(struct sk_buff *skb, const struct xt_target_param *par) @@ -90,6 +91,10 @@ static bool nfqueue_tg_v1_check(const struct xt_tgchk_param *par) const struct xt_NFQ_info_v1 *info = par->targinfo; u32 maxid; + if (unlikely(!rnd_inited)) { + get_random_bytes(&jhash_initval, sizeof(jhash_initval)); + rnd_inited = true; + } if (info->queues_total == 0) { pr_err("NFQUEUE: number of total queues is 0\n"); return false; @@ -135,7 +140,6 @@ static struct xt_target nfqueue_tg_reg[] __read_mostly = { static int __init nfqueue_tg_init(void) { - get_random_bytes(&jhash_initval, sizeof(jhash_initval)); return xt_register_targets(nfqueue_tg_reg, ARRAY_SIZE(nfqueue_tg_reg)); } diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c index d80b8192e0d4..87ae97e5516f 100644 --- a/net/netfilter/xt_RATEEST.c +++ b/net/netfilter/xt_RATEEST.c @@ -23,6 +23,7 @@ static DEFINE_MUTEX(xt_rateest_mutex); #define RATEEST_HSIZE 16 static struct hlist_head rateest_hash[RATEEST_HSIZE] __read_mostly; static unsigned int jhash_rnd __read_mostly; +static bool rnd_inited __read_mostly; static unsigned int xt_rateest_hash(const char *name) { @@ -93,6 +94,11 @@ static bool xt_rateest_tg_checkentry(const struct xt_tgchk_param *par) struct gnet_estimator est; } cfg; + if (unlikely(!rnd_inited)) { + get_random_bytes(&jhash_rnd, sizeof(jhash_rnd)); + rnd_inited = true; + } + est = xt_rateest_lookup(info->name); if (est) { /* @@ -164,7 +170,6 @@ static int __init xt_rateest_tg_init(void) for (i = 0; i < ARRAY_SIZE(rateest_hash); i++) INIT_HLIST_HEAD(&rateest_hash[i]); - get_random_bytes(&jhash_rnd, sizeof(jhash_rnd)); return xt_register_target(&xt_rateest_tg_reg); } -- GitLab