netfilter: nf_nat: fix locking in nf_nat_seq_adjust()

nf_nat_seq_adjust() needs to grab nf_nat_seqofs_lock to protect against
concurrent changes to the sequence adjustment data.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Patrick McHardy 2013-07-28 22:54:09 +02:00 committed by Pablo Neira Ayuso
parent 02982c27ba
commit 0658cdc8f3

View file

@ -373,6 +373,7 @@ nf_nat_seq_adjust(struct sk_buff *skb,
s16 seqoff, ackoff;
struct nf_conn_nat *nat = nfct_nat(ct);
struct nf_nat_seq *this_way, *other_way;
int res;
dir = CTINFO2DIR(ctinfo);
@ -383,6 +384,7 @@ nf_nat_seq_adjust(struct sk_buff *skb,
return 0;
tcph = (void *)skb->data + protoff;
spin_lock_bh(&nf_nat_seqofs_lock);
if (after(ntohl(tcph->seq), this_way->correction_pos))
seqoff = this_way->offset_after;
else
@ -407,7 +409,10 @@ nf_nat_seq_adjust(struct sk_buff *skb,
tcph->seq = newseq;
tcph->ack_seq = newack;
return nf_nat_sack_adjust(skb, protoff, tcph, ct, ctinfo);
res = nf_nat_sack_adjust(skb, protoff, tcph, ct, ctinfo);
spin_unlock_bh(&nf_nat_seqofs_lock);
return res;
}
/* Setup NAT on this expected conntrack so it follows master. */