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authorPablo Neira Ayuso <pablo@netfilter.org>2012-02-24 12:18:38 +0100
committerPablo Neira Ayuso <pablo@netfilter.org>2012-02-24 12:19:57 +0100
commit279072882dc0149e5740dace075e1a49f087046d (patch)
tree0a375ec930d918c2a0a622e613a59cd8b9b15486 /net
parent4a2258ddddefeef3291c0fc66437c73d84261a1e (diff)
downloadlinux-linaro-stable-279072882dc0149e5740dace075e1a49f087046d.tar.gz
Revert "netfilter: ctnetlink: fix soft lockup when netlink adds new entries"
This reverts commit af14cca162ddcdea017b648c21b9b091e4bf1fa4. This patch contains a race condition between packets and ctnetlink in the conntrack addition. A new patch to fix this issue follows up. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
-rw-r--r--net/netfilter/nf_conntrack_netlink.c43
1 files changed, 27 insertions, 16 deletions
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index cc705175765c..9307b033c0c9 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1367,12 +1367,15 @@ ctnetlink_create_conntrack(struct net *net, u16 zone,
nf_ct_protonum(ct));
if (helper == NULL) {
rcu_read_unlock();
+ spin_unlock_bh(&nf_conntrack_lock);
#ifdef CONFIG_MODULES
if (request_module("nfct-helper-%s", helpname) < 0) {
+ spin_lock_bh(&nf_conntrack_lock);
err = -EOPNOTSUPP;
goto err1;
}
+ spin_lock_bh(&nf_conntrack_lock);
rcu_read_lock();
helper = __nf_conntrack_helper_find(helpname,
nf_ct_l3num(ct),
@@ -1466,10 +1469,7 @@ ctnetlink_create_conntrack(struct net *net, u16 zone,
tstamp->start = ktime_to_ns(ktime_get_real());
add_timer(&ct->timeout);
- spin_lock_bh(&nf_conntrack_lock);
nf_conntrack_hash_insert(ct);
- nf_conntrack_get(&ct->ct_general);
- spin_unlock_bh(&nf_conntrack_lock);
rcu_read_unlock();
return ct;
@@ -1490,7 +1490,6 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
struct nf_conntrack_tuple otuple, rtuple;
struct nf_conntrack_tuple_hash *h = NULL;
struct nfgenmsg *nfmsg = nlmsg_data(nlh);
- struct nf_conn *ct;
u_int8_t u3 = nfmsg->nfgen_family;
u16 zone;
int err;
@@ -1513,22 +1512,25 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
spin_lock_bh(&nf_conntrack_lock);
if (cda[CTA_TUPLE_ORIG])
- h = nf_conntrack_find_get(net, zone, &otuple);
+ h = __nf_conntrack_find(net, zone, &otuple);
else if (cda[CTA_TUPLE_REPLY])
- h = nf_conntrack_find_get(net, zone, &rtuple);
- spin_unlock_bh(&nf_conntrack_lock);
+ h = __nf_conntrack_find(net, zone, &rtuple);
if (h == NULL) {
err = -ENOENT;
if (nlh->nlmsg_flags & NLM_F_CREATE) {
+ struct nf_conn *ct;
enum ip_conntrack_events events;
ct = ctnetlink_create_conntrack(net, zone, cda, &otuple,
&rtuple, u3);
- if (IS_ERR(ct))
- return PTR_ERR(ct);
-
+ if (IS_ERR(ct)) {
+ err = PTR_ERR(ct);
+ goto out_unlock;
+ }
err = 0;
+ nf_conntrack_get(&ct->ct_general);
+ spin_unlock_bh(&nf_conntrack_lock);
if (test_bit(IPS_EXPECTED_BIT, &ct->status))
events = IPCT_RELATED;
else
@@ -1543,19 +1545,23 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
ct, NETLINK_CB(skb).pid,
nlmsg_report(nlh));
nf_ct_put(ct);
- }
+ } else
+ spin_unlock_bh(&nf_conntrack_lock);
return err;
}
/* implicit 'else' */
+ /* We manipulate the conntrack inside the global conntrack table lock,
+ * so there's no need to increase the refcount */
err = -EEXIST;
- ct = nf_ct_tuplehash_to_ctrack(h);
if (!(nlh->nlmsg_flags & NLM_F_EXCL)) {
- spin_lock_bh(&nf_conntrack_lock);
+ struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
+
err = ctnetlink_change_conntrack(ct, cda);
- spin_unlock_bh(&nf_conntrack_lock);
if (err == 0) {
+ nf_conntrack_get(&ct->ct_general);
+ spin_unlock_bh(&nf_conntrack_lock);
nf_conntrack_eventmask_report((1 << IPCT_REPLY) |
(1 << IPCT_ASSURED) |
(1 << IPCT_HELPER) |
@@ -1564,10 +1570,15 @@ ctnetlink_new_conntrack(struct sock *ctnl, struct sk_buff *skb,
(1 << IPCT_MARK),
ct, NETLINK_CB(skb).pid,
nlmsg_report(nlh));
- }
+ nf_ct_put(ct);
+ } else
+ spin_unlock_bh(&nf_conntrack_lock);
+
+ return err;
}
- nf_ct_put(ct);
+out_unlock:
+ spin_unlock_bh(&nf_conntrack_lock);
return err;
}