Since nf_ct_expect_dst_hash() may be called without nf_conntrack_lock
locked, nf_ct_expect_hash_rnd should be initialized in the atomic way.
Signed-off-by: Changli Gao <xiaosuo@xxxxxxxxx>
---
net/netfilter/nf_conntrack_expect.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c
index 46e8966..e2bb3ef 100644
--- a/net/netfilter/nf_conntrack_expect.c
+++ b/net/netfilter/nf_conntrack_expect.c
@@ -34,7 +34,6 @@ EXPORT_SYMBOL_GPL(nf_ct_expect_hsize);
static unsigned int nf_ct_expect_hash_rnd __read_mostly;
unsigned int nf_ct_expect_max __read_mostly;
-static int nf_ct_expect_hash_rnd_initted __read_mostly;
static struct kmem_cache *nf_ct_expect_cachep __read_mostly;
@@ -77,10 +76,13 @@ static unsigned int nf_ct_expect_dst_hash(const struct nf_conntrack_tuple *tuple
{
unsigned int hash;
- if (unlikely(!nf_ct_expect_hash_rnd_initted)) {
- get_random_bytes(&nf_ct_expect_hash_rnd,
- sizeof(nf_ct_expect_hash_rnd));
- nf_ct_expect_hash_rnd_initted = 1;
+ if (unlikely(!nf_ct_expect_hash_rnd)) {
+ unsigned int rand;
+
+ do {
+ get_random_bytes(&rand, sizeof(rand));
+ } while (!rand);
+ cmpxchg(&nf_ct_expect_hash_rnd, 0, rand);
}
hash = jhash2(tuple->dst.u3.all, ARRAY_SIZE(tuple->dst.u3.all),
--
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