A potential race condition when generating connlimit_rnd is also fixed.
Signed-off-by: Changli Gao <xiaosuo@xxxxxxxxx>
---
net/netfilter/xt_connlimit.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/net/netfilter/xt_connlimit.c b/net/netfilter/xt_connlimit.c
index da56d6e..c6d5a83 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) {
--
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