From mboxrd@z Thu Jan 1 00:00:00 1970 From: kaber@trash.net Subject: [PATCH 4/8] netfilter: nf_queue: reject NF_STOLEN verdicts from userspace Date: Tue, 30 Aug 2011 16:41:17 +0200 Message-ID: <1314715281-26233-5-git-send-email-kaber@trash.net> References: <1314715281-26233-1-git-send-email-kaber@trash.net> Cc: netfilter-devel@vger.kernel.org, netdev@vger.kernel.org To: davem@davemloft.net Return-path: Received: from stinky.trash.net ([213.144.137.162]:56966 "EHLO stinky.trash.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753221Ab1H3OlZ (ORCPT ); Tue, 30 Aug 2011 10:41:25 -0400 In-Reply-To: <1314715281-26233-1-git-send-email-kaber@trash.net> Sender: netfilter-devel-owner@vger.kernel.org List-ID: From: Florian Westphal 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 Cc: Eric Dumazet Signed-off-by: Florian Westphal Signed-off-by: Patrick McHardy --- 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 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; } -- 1.7.2.3