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| author | Changli Gao <xiaosuo@gmail.com> | 2011-03-15 13:26:32 +0100 |
|---|---|---|
| committer | Patrick McHardy <kaber@trash.net> | 2011-03-15 13:26:32 +0100 |
| commit | 4656c4d61adb8dc3ee04c08f57a5cc7598814420 (patch) | |
| tree | 03c01d2bf4e56fa33ede99f8128839727d3878af | |
| parent | 3e0d5149e6dcbe7111a63773a07c5b33f7ca7236 (diff) | |
| download | linux-4656c4d61adb8dc3ee04c08f57a5cc7598814420.tar.bz2 | |
netfilter: xt_connlimit: remove connlimit_rnd_inited
A potential race condition when generating connlimit_rnd is also fixed.
Signed-off-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
| -rw-r--r-- | net/netfilter/xt_connlimit.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/net/netfilter/xt_connlimit.c b/net/netfilter/xt_connlimit.c index da56d6ec13c9..c6d5a83450c9 100644 --- a/net/netfilter/xt_connlimit.c +++ b/net/netfilter/xt_connlimit.c @@ -44,7 +44,6 @@ struct xt_connlimit_data { }; static u_int32_t connlimit_rnd __read_mostly; -static bool connlimit_rnd_inited __read_mostly; static inline unsigned int connlimit_iphash(__be32 addr) { @@ -226,9 +225,13 @@ static int connlimit_mt_check(const struct xt_mtchk_param *par) unsigned int i; int ret; - if (unlikely(!connlimit_rnd_inited)) { - get_random_bytes(&connlimit_rnd, sizeof(connlimit_rnd)); - connlimit_rnd_inited = true; + if (unlikely(!connlimit_rnd)) { + u_int32_t rand; + + do { + get_random_bytes(&rand, sizeof(rand)); + } while (!rand); + cmpxchg(&connlimit_rnd, 0, rand); } ret = nf_ct_l3proto_try_module_get(par->family); if (ret < 0) { |