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| author | Florian Westphal <fw@strlen.de> | 2011-08-30 15:01:20 +0200 |
|---|---|---|
| committer | Patrick McHardy <kaber@trash.net> | 2011-08-30 15:01:20 +0200 |
| commit | c6675233f9015d3c0460c8aab53ed9b99d915c64 (patch) | |
| tree | 3d1b9b71059be24fe3a35411eecc62000bba5abc | |
| parent | 9823d9ff483af4ce8804a9eb69600ca739cd1f58 (diff) | |
| download | op-kernel-dev-c6675233f9015d3c0460c8aab53ed9b99d915c64.zip op-kernel-dev-c6675233f9015d3c0460c8aab53ed9b99d915c64.tar.gz | |
netfilter: nf_queue: reject NF_STOLEN verdicts from userspace
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 Michal Miroslaw.
This is complementary to commit fad54440438a7c231a6ae347738423cbabc936d9
(netfilter: avoid double free in nf_reinject).
Cc: Julian Anastasov <ja@ssi.bg>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
| -rw-r--r-- | net/ipv4/netfilter/ip_queue.c | 11 | ||||
| -rw-r--r-- | net/ipv6/netfilter/ip6_queue.c | 11 | ||||
| -rw-r--r-- | 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 48f7d5b..e59aabd 100644 --- a/net/ipv4/netfilter/ip_queue.c +++ b/net/ipv4/netfilter/ip_queue.c @@ -314,7 +314,7 @@ 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); @@ -359,12 +359,9 @@ 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 87b243a..e63c397 100644 --- a/net/ipv6/netfilter/ip6_queue.c +++ b/net/ipv6/netfilter/ip6_queue.c @@ -314,7 +314,7 @@ 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); @@ -359,12 +359,9 @@ 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 00bd475..a80b0cb 100644 --- a/net/netfilter/nfnetlink_queue.c +++ b/net/netfilter/nfnetlink_queue.c @@ -646,8 +646,8 @@ 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; } |
