netfilter: nf_ct_helper: unlink helper again when hash resize happen

From: Liping Zhang <liping.zhang@spreadtrum.com>

Similar to ctnl_untimeout, when hash resize happened, we should try
to do unhelp from the 0# bucket again.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 13 insertions, 6 deletions

diff --git a/net/netfilter/nf_conntrack_helper.c b/net/netfilter/nf_conntrack_helper.c
index 3a1a88b9bafa..a4294e949cdc 100644
--- a/net/netfilter/nf_conntrack_helper.c
+++ b/net/netfilter/nf_conntrack_helper.c
@@ -409,6 +409,8 @@ void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me)
         struct nf_conntrack_expect *exp;
         const struct hlist_node *next;
         const struct hlist_nulls_node *nn;
+        unsigned int last_hsize;
+        spinlock_t *lock;
         struct net *net;
         unsigned int i;
 
@@ -446,13 +448,18 @@ void nf_conntrack_helper_unregister(struct nf_conntrack_helper *me)
         rtnl_unlock();
 
         local_bh_disable();
-        for (i = 0; i < nf_conntrack_htable_size; i++) {
-                nf_conntrack_lock(&nf_conntrack_locks[i % CONNTRACK_LOCKS]);
-                if (i < nf_conntrack_htable_size) {
-                        hlist_nulls_for_each_entry(h, nn, &nf_conntrack_hash[i], hnnode)
-                                unhelp(h, me);
+restart:
+        last_hsize = nf_conntrack_htable_size;
+        for (i = 0; i < last_hsize; i++) {
+                lock = &nf_conntrack_locks[i % CONNTRACK_LOCKS];
+                nf_conntrack_lock(lock);
+                if (last_hsize != nf_conntrack_htable_size) {
+                        spin_unlock(lock);
+                        goto restart;
                 }
-                spin_unlock(&nf_conntrack_locks[i % CONNTRACK_LOCKS]);
+                hlist_nulls_for_each_entry(h, nn, &nf_conntrack_hash[i], hnnode)
+                        unhelp(h, me);
+                spin_unlock(lock);
         }
         local_bh_enable();
 }