From 2a50d805e59ed18265fca44825719f35927af8af Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 6 Jan 2014 13:54:30 +0100 Subject: [PATCH] Revert "netfilter: avoid get_random_bytes calls" This reverts commit a42b99a6e329654d376b330de057eff87686d890. Hannes Frederic Sowa reported some problems with this patch, more specifically that prandom_u32() may not be ready at boot time, see: http://marc.info/?l=linux-netdev&m=138896532403533&w=2 Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nfnetlink_log.c | 8 ++++++++ net/netfilter/nft_hash.c | 2 +- net/netfilter/xt_RATEEST.c | 2 +- net/netfilter/xt_connlimit.c | 2 +- net/netfilter/xt_hashlimit.c | 2 +- net/netfilter/xt_recent.c | 2 +- 6 files changed, 13 insertions(+), 5 deletions(-) diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index 7d4254b0dc6b..3c4b69e5fe17 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -28,6 +28,8 @@ #include #include #include +#include +#include #include #include #include @@ -73,6 +75,7 @@ struct nfulnl_instance { }; #define INSTANCE_BUCKETS 16 +static unsigned int hash_init; static int nfnl_log_net_id __read_mostly; @@ -1063,6 +1066,11 @@ static int __init nfnetlink_log_init(void) { int status = -ENOMEM; + /* it's not really all that important to have a random value, so + * we can do this from the init function, even if there hasn't + * been that much entropy yet */ + get_random_bytes(&hash_init, sizeof(hash_init)); + netlink_register_notifier(&nfulnl_rtnl_notifier); status = nfnetlink_subsys_register(&nfulnl_subsys); if (status < 0) { diff --git a/net/netfilter/nft_hash.c b/net/netfilter/nft_hash.c index 6aae699aeb46..3d3f8fce10a5 100644 --- a/net/netfilter/nft_hash.c +++ b/net/netfilter/nft_hash.c @@ -164,7 +164,7 @@ static int nft_hash_init(const struct nft_set *set, unsigned int cnt, i; if (unlikely(!nft_hash_rnd_initted)) { - nft_hash_rnd = prandom_u32(); + get_random_bytes(&nft_hash_rnd, 4); nft_hash_rnd_initted = true; } diff --git a/net/netfilter/xt_RATEEST.c b/net/netfilter/xt_RATEEST.c index 190854be7629..370adf622cef 100644 --- a/net/netfilter/xt_RATEEST.c +++ b/net/netfilter/xt_RATEEST.c @@ -100,7 +100,7 @@ static int xt_rateest_tg_checkentry(const struct xt_tgchk_param *par) int ret; if (unlikely(!rnd_inited)) { - jhash_rnd = prandom_u32(); + get_random_bytes(&jhash_rnd, sizeof(jhash_rnd)); rnd_inited = true; } diff --git a/net/netfilter/xt_connlimit.c b/net/netfilter/xt_connlimit.c index 7671e8214919..c40b2695633b 100644 --- a/net/netfilter/xt_connlimit.c +++ b/net/netfilter/xt_connlimit.c @@ -229,7 +229,7 @@ static int connlimit_mt_check(const struct xt_mtchk_param *par) u_int32_t rand; do { - rand = prandom_u32(); + get_random_bytes(&rand, sizeof(rand)); } while (!rand); cmpxchg(&connlimit_rnd, 0, rand); } diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c index d819f62b3b7c..a3910fc2122b 100644 --- a/net/netfilter/xt_hashlimit.c +++ b/net/netfilter/xt_hashlimit.c @@ -177,7 +177,7 @@ dsthash_alloc_init(struct xt_hashlimit_htable *ht, /* initialize hash with random val at the time we allocate * the first hashtable entry */ if (unlikely(!ht->rnd_initialized)) { - ht->rnd = prandom_u32(); + get_random_bytes(&ht->rnd, sizeof(ht->rnd)); ht->rnd_initialized = true; } diff --git a/net/netfilter/xt_recent.c b/net/netfilter/xt_recent.c index bfdc29f1a04a..1e657cf715c4 100644 --- a/net/netfilter/xt_recent.c +++ b/net/netfilter/xt_recent.c @@ -334,7 +334,7 @@ static int recent_mt_check(const struct xt_mtchk_param *par, size_t sz; if (unlikely(!hash_rnd_inited)) { - hash_rnd = prandom_u32(); + get_random_bytes(&hash_rnd, sizeof(hash_rnd)); hash_rnd_inited = true; } if (info->check_set & ~XT_RECENT_VALID_FLAGS) { -- 2.30.2