[NETFILTER]: ctnetlink: fix deadlock in table dumping
ip_conntrack_put must not be called while holding ip_conntrack_lock
since destroy_conntrack takes it again.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index af48459..6527d4e 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -429,9 +429,9 @@
cb->args[0], *id);
read_lock_bh(&nf_conntrack_lock);
+ last = (struct nf_conn *)cb->args[1];
for (; cb->args[0] < nf_conntrack_htable_size; cb->args[0]++) {
restart:
- last = (struct nf_conn *)cb->args[1];
list_for_each_prev(i, &nf_conntrack_hash[cb->args[0]]) {
h = (struct nf_conntrack_tuple_hash *) i;
if (DIRECTION(h) != IP_CT_DIR_ORIGINAL)
@@ -442,13 +442,10 @@
* then dump everything. */
if (l3proto && L3PROTO(ct) != l3proto)
continue;
- if (last != NULL) {
- if (ct == last) {
- nf_ct_put(last);
- cb->args[1] = 0;
- last = NULL;
- } else
+ if (cb->args[1]) {
+ if (ct != last)
continue;
+ cb->args[1] = 0;
}
if (ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq,
@@ -459,17 +456,17 @@
goto out;
}
}
- if (last != NULL) {
- nf_ct_put(last);
+ if (cb->args[1]) {
cb->args[1] = 0;
goto restart;
}
}
out:
read_unlock_bh(&nf_conntrack_lock);
+ if (last)
+ nf_ct_put(last);
DEBUGP("leaving, last bucket=%lu id=%u\n", cb->args[0], *id);
-
return skb->len;
}