diff options
Diffstat (limited to 'net/netfilter/nf_conntrack_core.c')
-rw-r--r-- | net/netfilter/nf_conntrack_core.c | 30 |
1 files changed, 27 insertions, 3 deletions
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index b793b55d1488..06520bf30f29 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -763,10 +763,18 @@ __nf_conntrack_confirm(struct sk_buff *skb) * REJECT will give spurious warnings here. */ - /* No external references means no one else could have - * confirmed us. + /* Another skb with the same unconfirmed conntrack may + * win the race. This may happen for bridge(br_flood) + * or broadcast/multicast packets do skb_clone with + * unconfirmed conntrack. */ - WARN_ON(nf_ct_is_confirmed(ct)); + if (unlikely(nf_ct_is_confirmed(ct))) { + WARN_ON_ONCE(1); + nf_conntrack_double_unlock(hash, reply_hash); + local_bh_enable(); + return NF_DROP; + } + pr_debug("Confirming conntrack %p\n", ct); /* We have to check the DYING flag after unlink to prevent * a race against nf_ct_get_next_corpse() possibly called from @@ -869,6 +877,22 @@ nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple, } if (nf_ct_key_equal(h, tuple, zone, net)) { + /* Tuple is taken already, so caller will need to find + * a new source port to use. + * + * Only exception: + * If the *original tuples* are identical, then both + * conntracks refer to the same flow. + * This is a rare situation, it can occur e.g. when + * more than one UDP packet is sent from same socket + * in different threads. + * + * Let nf_ct_resolve_clash() deal with this later. + */ + if (nf_ct_tuple_equal(&ignored_conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple, + &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple)) + continue; + NF_CT_STAT_INC_ATOMIC(net, found); rcu_read_unlock(); return 1; |