A userspace listener may send (bogus) NF_STOLEN verdict, which causes skb leak.
This problem was previously fixed via
64507fdbc29c3a622180378210ecea8659b14e40 (netfilter:
nf_queue: fix NF_STOLEN skb leak) but this had to be reverted because
NF_STOLEN can also be returned by a netfilter hook when iterating the
rules in nf_reinject.
Reject userspace NF_STOLEN verdict, as suggested by Michał Mirosław.
This is complementary to commit fad54440438a7c231a6ae347738423cbabc936d9
(netfilter: avoid double free in nf_reinject).
Cc: Julian Anastasov <ja@xxxxxx>
Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
---
net/ipv4/netfilter/ip_queue.c | 11 ++++-------
net/ipv6/netfilter/ip6_queue.c | 11 ++++-------
net/netfilter/nfnetlink_queue.c | 4 ++--
3 files changed, 10 insertions(+), 16 deletions(-)
diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c
index d2c1311..8ad0bb1 100644
--- a/net/ipv4/netfilter/ip_queue.c
+++ b/net/ipv4/netfilter/ip_queue.c
@@ -312,7 +312,7 @@ ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
{
struct nf_queue_entry *entry;
- if (vmsg->value > NF_MAX_VERDICT)
+ if (vmsg->value > NF_MAX_VERDICT || vmsg->value == NF_STOLEN)
return -EINVAL;
entry = ipq_find_dequeue_entry(vmsg->id);
@@ -357,12 +357,9 @@ ipq_receive_peer(struct ipq_peer_msg *pmsg,
break;
case IPQM_VERDICT:
- if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
- status = -EINVAL;
- else
- status = ipq_set_verdict(&pmsg->msg.verdict,
- len - sizeof(*pmsg));
- break;
+ status = ipq_set_verdict(&pmsg->msg.verdict,
+ len - sizeof(*pmsg));
+ break;
default:
status = -EINVAL;
}
diff --git a/net/ipv6/netfilter/ip6_queue.c b/net/ipv6/netfilter/ip6_queue.c
index 413ab07..974d07f 100644
--- a/net/ipv6/netfilter/ip6_queue.c
+++ b/net/ipv6/netfilter/ip6_queue.c
@@ -312,7 +312,7 @@ ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
{
struct nf_queue_entry *entry;
- if (vmsg->value > NF_MAX_VERDICT)
+ if (vmsg->value > NF_MAX_VERDICT || vmsg->value == NF_STOLEN)
return -EINVAL;
entry = ipq_find_dequeue_entry(vmsg->id);
@@ -357,12 +357,9 @@ ipq_receive_peer(struct ipq_peer_msg *pmsg,
break;
case IPQM_VERDICT:
- if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
- status = -EINVAL;
- else
- status = ipq_set_verdict(&pmsg->msg.verdict,
- len - sizeof(*pmsg));
- break;
+ status = ipq_set_verdict(&pmsg->msg.verdict,
+ len - sizeof(*pmsg));
+ break;
default:
status = -EINVAL;
}
diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
index fbfcd83..89cb76a 100644
--- a/net/netfilter/nfnetlink_queue.c
+++ b/net/netfilter/nfnetlink_queue.c
@@ -645,8 +645,8 @@ verdicthdr_get(const struct nlattr * const nfqa[])
return NULL;
vhdr = nla_data(nfqa[NFQA_VERDICT_HDR]);
- verdict = ntohl(vhdr->verdict);
- if ((verdict & NF_VERDICT_MASK) > NF_MAX_VERDICT)
+ verdict = ntohl(vhdr->verdict) & NF_VERDICT_MASK;
+ if (verdict > NF_MAX_VERDICT || verdict == NF_STOLEN)
return NULL;
return vhdr;
}
--
1.7.3.4
--
To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
