From e9c284ec4b41c827f4369973d2792992849e4fa5 Mon Sep 17 00:00:00 2001 From: Michael Braun Date: Wed, 6 May 2020 11:46:25 +0200 Subject: [PATCH 1/5] netfilter: nft_reject_bridge: enable reject with bridge vlan Currently, using the bridge reject target with tagged packets results in untagged packets being sent back. Fix this by mirroring the vlan id as well. Fixes: 85f5b3086a04 ("netfilter: bridge: add reject support") Signed-off-by: Michael Braun Signed-off-by: Pablo Neira Ayuso --- net/bridge/netfilter/nft_reject_bridge.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/bridge/netfilter/nft_reject_bridge.c b/net/bridge/netfilter/nft_reject_bridge.c index b325b569e761..f48cf4cfb80f 100644 --- a/net/bridge/netfilter/nft_reject_bridge.c +++ b/net/bridge/netfilter/nft_reject_bridge.c @@ -31,6 +31,12 @@ static void nft_reject_br_push_etherhdr(struct sk_buff *oldskb, ether_addr_copy(eth->h_dest, eth_hdr(oldskb)->h_source); eth->h_proto = eth_hdr(oldskb)->h_proto; skb_pull(nskb, ETH_HLEN); + + if (skb_vlan_tag_present(oldskb)) { + u16 vid = skb_vlan_tag_get(oldskb); + + __vlan_hwaccel_put_tag(nskb, oldskb->vlan_proto, vid); + } } static int nft_bridge_iphdr_validate(struct sk_buff *skb) From a164b95ad6055c50612795882f35e0efda1f1390 Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Thu, 14 May 2020 13:31:21 +0200 Subject: [PATCH 2/5] netfilter: ipset: Fix subcounter update skip If IPSET_FLAG_SKIP_SUBCOUNTER_UPDATE is set, user requested to not update counters in sub sets. Therefore IPSET_FLAG_SKIP_COUNTER_UPDATE must be set, not unset. Fixes: 6e01781d1c80e ("netfilter: ipset: set match: add support to match the counters") Signed-off-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso --- net/netfilter/ipset/ip_set_list_set.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/netfilter/ipset/ip_set_list_set.c b/net/netfilter/ipset/ip_set_list_set.c index cd747c0962fd..5a67f7966574 100644 --- a/net/netfilter/ipset/ip_set_list_set.c +++ b/net/netfilter/ipset/ip_set_list_set.c @@ -59,7 +59,7 @@ list_set_ktest(struct ip_set *set, const struct sk_buff *skb, /* Don't lookup sub-counters at all */ opt->cmdflags &= ~IPSET_FLAG_MATCH_COUNTERS; if (opt->cmdflags & IPSET_FLAG_SKIP_SUBCOUNTER_UPDATE) - opt->cmdflags &= ~IPSET_FLAG_SKIP_COUNTER_UPDATE; + opt->cmdflags |= IPSET_FLAG_SKIP_COUNTER_UPDATE; list_for_each_entry_rcu(e, &map->members, list) { ret = ip_set_test(e->id, skb, par, opt); if (ret <= 0) From 4c559f15efcc43b996f4da528cd7f9483aaca36d Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 14 May 2020 14:14:23 +0200 Subject: [PATCH 3/5] netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code Dan Carpenter says: "Smatch complains that the value for "cmd" comes from the network and can't be trusted." Add pptp_msg_name() helper function that checks for the array boundary. Fixes: f09943fefe6b ("[NETFILTER]: nf_conntrack/nf_nat: add PPTP helper port") Reported-by: Dan Carpenter Signed-off-by: Pablo Neira Ayuso --- include/linux/netfilter/nf_conntrack_pptp.h | 2 +- net/ipv4/netfilter/nf_nat_pptp.c | 7 +-- net/netfilter/nf_conntrack_pptp.c | 62 ++++++++++++--------- 3 files changed, 38 insertions(+), 33 deletions(-) diff --git a/include/linux/netfilter/nf_conntrack_pptp.h b/include/linux/netfilter/nf_conntrack_pptp.h index fcc409de31a4..6a4ff6d5ebc2 100644 --- a/include/linux/netfilter/nf_conntrack_pptp.h +++ b/include/linux/netfilter/nf_conntrack_pptp.h @@ -10,7 +10,7 @@ #include #include -extern const char *const pptp_msg_name[]; +extern const char *const pptp_msg_name(u_int16_t msg); /* state of the control session */ enum pptp_ctrlsess_state { diff --git a/net/ipv4/netfilter/nf_nat_pptp.c b/net/ipv4/netfilter/nf_nat_pptp.c index 3c25a467b3ef..7afde8828b4c 100644 --- a/net/ipv4/netfilter/nf_nat_pptp.c +++ b/net/ipv4/netfilter/nf_nat_pptp.c @@ -166,8 +166,7 @@ pptp_outbound_pkt(struct sk_buff *skb, break; default: pr_debug("unknown outbound packet 0x%04x:%s\n", msg, - msg <= PPTP_MSG_MAX ? pptp_msg_name[msg] : - pptp_msg_name[0]); + pptp_msg_name(msg)); fallthrough; case PPTP_SET_LINK_INFO: /* only need to NAT in case PAC is behind NAT box */ @@ -268,9 +267,7 @@ pptp_inbound_pkt(struct sk_buff *skb, pcid_off = offsetof(union pptp_ctrl_union, setlink.peersCallID); break; default: - pr_debug("unknown inbound packet %s\n", - msg <= PPTP_MSG_MAX ? pptp_msg_name[msg] : - pptp_msg_name[0]); + pr_debug("unknown inbound packet %s\n", pptp_msg_name(msg)); fallthrough; case PPTP_START_SESSION_REQUEST: case PPTP_START_SESSION_REPLY: diff --git a/net/netfilter/nf_conntrack_pptp.c b/net/netfilter/nf_conntrack_pptp.c index a971183f11af..7ad247784cfa 100644 --- a/net/netfilter/nf_conntrack_pptp.c +++ b/net/netfilter/nf_conntrack_pptp.c @@ -72,24 +72,32 @@ EXPORT_SYMBOL_GPL(nf_nat_pptp_hook_expectfn); #if defined(DEBUG) || defined(CONFIG_DYNAMIC_DEBUG) /* PptpControlMessageType names */ -const char *const pptp_msg_name[] = { - "UNKNOWN_MESSAGE", - "START_SESSION_REQUEST", - "START_SESSION_REPLY", - "STOP_SESSION_REQUEST", - "STOP_SESSION_REPLY", - "ECHO_REQUEST", - "ECHO_REPLY", - "OUT_CALL_REQUEST", - "OUT_CALL_REPLY", - "IN_CALL_REQUEST", - "IN_CALL_REPLY", - "IN_CALL_CONNECT", - "CALL_CLEAR_REQUEST", - "CALL_DISCONNECT_NOTIFY", - "WAN_ERROR_NOTIFY", - "SET_LINK_INFO" +static const char *const pptp_msg_name_array[PPTP_MSG_MAX + 1] = { + [0] = "UNKNOWN_MESSAGE", + [PPTP_START_SESSION_REQUEST] = "START_SESSION_REQUEST", + [PPTP_START_SESSION_REPLY] = "START_SESSION_REPLY", + [PPTP_STOP_SESSION_REQUEST] = "STOP_SESSION_REQUEST", + [PPTP_STOP_SESSION_REPLY] = "STOP_SESSION_REPLY", + [PPTP_ECHO_REQUEST] = "ECHO_REQUEST", + [PPTP_ECHO_REPLY] = "ECHO_REPLY", + [PPTP_OUT_CALL_REQUEST] = "OUT_CALL_REQUEST", + [PPTP_OUT_CALL_REPLY] = "OUT_CALL_REPLY", + [PPTP_IN_CALL_REQUEST] = "IN_CALL_REQUEST", + [PPTP_IN_CALL_REPLY] = "IN_CALL_REPLY", + [PPTP_IN_CALL_CONNECT] = "IN_CALL_CONNECT", + [PPTP_CALL_CLEAR_REQUEST] = "CALL_CLEAR_REQUEST", + [PPTP_CALL_DISCONNECT_NOTIFY] = "CALL_DISCONNECT_NOTIFY", + [PPTP_WAN_ERROR_NOTIFY] = "WAN_ERROR_NOTIFY", + [PPTP_SET_LINK_INFO] = "SET_LINK_INFO" }; + +const char *const pptp_msg_name(u_int16_t msg) +{ + if (msg > PPTP_MSG_MAX) + return pptp_msg_name_array[0]; + + return pptp_msg_name_array[msg]; +} EXPORT_SYMBOL(pptp_msg_name); #endif @@ -276,7 +284,7 @@ pptp_inbound_pkt(struct sk_buff *skb, unsigned int protoff, typeof(nf_nat_pptp_hook_inbound) nf_nat_pptp_inbound; msg = ntohs(ctlh->messageType); - pr_debug("inbound control message %s\n", pptp_msg_name[msg]); + pr_debug("inbound control message %s\n", pptp_msg_name(msg)); switch (msg) { case PPTP_START_SESSION_REPLY: @@ -311,7 +319,7 @@ pptp_inbound_pkt(struct sk_buff *skb, unsigned int protoff, pcid = pptpReq->ocack.peersCallID; if (info->pns_call_id != pcid) goto invalid; - pr_debug("%s, CID=%X, PCID=%X\n", pptp_msg_name[msg], + pr_debug("%s, CID=%X, PCID=%X\n", pptp_msg_name(msg), ntohs(cid), ntohs(pcid)); if (pptpReq->ocack.resultCode == PPTP_OUTCALL_CONNECT) { @@ -328,7 +336,7 @@ pptp_inbound_pkt(struct sk_buff *skb, unsigned int protoff, goto invalid; cid = pptpReq->icreq.callID; - pr_debug("%s, CID=%X\n", pptp_msg_name[msg], ntohs(cid)); + pr_debug("%s, CID=%X\n", pptp_msg_name(msg), ntohs(cid)); info->cstate = PPTP_CALL_IN_REQ; info->pac_call_id = cid; break; @@ -347,7 +355,7 @@ pptp_inbound_pkt(struct sk_buff *skb, unsigned int protoff, if (info->pns_call_id != pcid) goto invalid; - pr_debug("%s, PCID=%X\n", pptp_msg_name[msg], ntohs(pcid)); + pr_debug("%s, PCID=%X\n", pptp_msg_name(msg), ntohs(pcid)); info->cstate = PPTP_CALL_IN_CONF; /* we expect a GRE connection from PAC to PNS */ @@ -357,7 +365,7 @@ pptp_inbound_pkt(struct sk_buff *skb, unsigned int protoff, case PPTP_CALL_DISCONNECT_NOTIFY: /* server confirms disconnect */ cid = pptpReq->disc.callID; - pr_debug("%s, CID=%X\n", pptp_msg_name[msg], ntohs(cid)); + pr_debug("%s, CID=%X\n", pptp_msg_name(msg), ntohs(cid)); info->cstate = PPTP_CALL_NONE; /* untrack this call id, unexpect GRE packets */ @@ -384,7 +392,7 @@ pptp_inbound_pkt(struct sk_buff *skb, unsigned int protoff, invalid: pr_debug("invalid %s: type=%d cid=%u pcid=%u " "cstate=%d sstate=%d pns_cid=%u pac_cid=%u\n", - msg <= PPTP_MSG_MAX ? pptp_msg_name[msg] : pptp_msg_name[0], + pptp_msg_name(msg), msg, ntohs(cid), ntohs(pcid), info->cstate, info->sstate, ntohs(info->pns_call_id), ntohs(info->pac_call_id)); return NF_ACCEPT; @@ -404,7 +412,7 @@ pptp_outbound_pkt(struct sk_buff *skb, unsigned int protoff, typeof(nf_nat_pptp_hook_outbound) nf_nat_pptp_outbound; msg = ntohs(ctlh->messageType); - pr_debug("outbound control message %s\n", pptp_msg_name[msg]); + pr_debug("outbound control message %s\n", pptp_msg_name(msg)); switch (msg) { case PPTP_START_SESSION_REQUEST: @@ -426,7 +434,7 @@ pptp_outbound_pkt(struct sk_buff *skb, unsigned int protoff, info->cstate = PPTP_CALL_OUT_REQ; /* track PNS call id */ cid = pptpReq->ocreq.callID; - pr_debug("%s, CID=%X\n", pptp_msg_name[msg], ntohs(cid)); + pr_debug("%s, CID=%X\n", pptp_msg_name(msg), ntohs(cid)); info->pns_call_id = cid; break; @@ -440,7 +448,7 @@ pptp_outbound_pkt(struct sk_buff *skb, unsigned int protoff, pcid = pptpReq->icack.peersCallID; if (info->pac_call_id != pcid) goto invalid; - pr_debug("%s, CID=%X PCID=%X\n", pptp_msg_name[msg], + pr_debug("%s, CID=%X PCID=%X\n", pptp_msg_name(msg), ntohs(cid), ntohs(pcid)); if (pptpReq->icack.resultCode == PPTP_INCALL_ACCEPT) { @@ -480,7 +488,7 @@ pptp_outbound_pkt(struct sk_buff *skb, unsigned int protoff, invalid: pr_debug("invalid %s: type=%d cid=%u pcid=%u " "cstate=%d sstate=%d pns_cid=%u pac_cid=%u\n", - msg <= PPTP_MSG_MAX ? pptp_msg_name[msg] : pptp_msg_name[0], + pptp_msg_name(msg), msg, ntohs(cid), ntohs(pcid), info->cstate, info->sstate, ntohs(info->pns_call_id), ntohs(info->pac_call_id)); return NF_ACCEPT; From ee04805ff54a63ffd90bc6749ebfe73473734ddb Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 24 May 2020 19:52:10 +0200 Subject: [PATCH 4/5] netfilter: conntrack: make conntrack userspace helpers work again Florian Westphal says: "Problem is that after the helper hook was merged back into the confirm one, the queueing itself occurs from the confirm hook, i.e. we queue from the last netfilter callback in the hook-list. Therefore, on return, the packet bypasses the confirm action and the connection is never committed to the main conntrack table. To fix this there are several ways: 1. revert the 'Fixes' commit and have a extra helper hook again. Works, but has the drawback of adding another indirect call for everyone. 2. Special case this: split the hooks only when userspace helper gets added, so queueing occurs at a lower priority again, and normal enqueue reinject would eventually call the last hook. 3. Extend the existing nf_queue ct update hook to allow a forced confirmation (plus run the seqadj code). This goes for 3)." Fixes: 827318feb69cb ("netfilter: conntrack: remove helper hook again") Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_core.c | 78 ++++++++++++++++++++++++++++--- 1 file changed, 72 insertions(+), 6 deletions(-) diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 1d57b95d3481..08e0c19f6b39 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -2016,22 +2016,18 @@ static void nf_conntrack_attach(struct sk_buff *nskb, const struct sk_buff *skb) nf_conntrack_get(skb_nfct(nskb)); } -static int nf_conntrack_update(struct net *net, struct sk_buff *skb) +static int __nf_conntrack_update(struct net *net, struct sk_buff *skb, + struct nf_conn *ct) { struct nf_conntrack_tuple_hash *h; struct nf_conntrack_tuple tuple; enum ip_conntrack_info ctinfo; struct nf_nat_hook *nat_hook; unsigned int status; - struct nf_conn *ct; int dataoff; u16 l3num; u8 l4num; - ct = nf_ct_get(skb, &ctinfo); - if (!ct || nf_ct_is_confirmed(ct)) - return 0; - l3num = nf_ct_l3num(ct); dataoff = get_l4proto(skb, skb_network_offset(skb), l3num, &l4num); @@ -2088,6 +2084,76 @@ static int nf_conntrack_update(struct net *net, struct sk_buff *skb) return 0; } +/* This packet is coming from userspace via nf_queue, complete the packet + * processing after the helper invocation in nf_confirm(). + */ +static int nf_confirm_cthelper(struct sk_buff *skb, struct nf_conn *ct, + enum ip_conntrack_info ctinfo) +{ + const struct nf_conntrack_helper *helper; + const struct nf_conn_help *help; + unsigned int protoff; + + help = nfct_help(ct); + if (!help) + return 0; + + helper = rcu_dereference(help->helper); + if (!(helper->flags & NF_CT_HELPER_F_USERSPACE)) + return 0; + + switch (nf_ct_l3num(ct)) { + case NFPROTO_IPV4: + protoff = skb_network_offset(skb) + ip_hdrlen(skb); + break; +#if IS_ENABLED(CONFIG_IPV6) + case NFPROTO_IPV6: { + __be16 frag_off; + u8 pnum; + + pnum = ipv6_hdr(skb)->nexthdr; + protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &pnum, + &frag_off); + if (protoff < 0 || (frag_off & htons(~0x7)) != 0) + return 0; + break; + } +#endif + default: + return 0; + } + + if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) && + !nf_is_loopback_packet(skb)) { + if (!nf_ct_seq_adjust(skb, ct, ctinfo, protoff)) { + NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop); + return -1; + } + } + + /* We've seen it coming out the other side: confirm it */ + return nf_conntrack_confirm(skb) == NF_DROP ? - 1 : 0; +} + +static int nf_conntrack_update(struct net *net, struct sk_buff *skb) +{ + enum ip_conntrack_info ctinfo; + struct nf_conn *ct; + int err; + + ct = nf_ct_get(skb, &ctinfo); + if (!ct) + return 0; + + if (!nf_ct_is_confirmed(ct)) { + err = __nf_conntrack_update(net, skb, ct); + if (err < 0) + return err; + } + + return nf_confirm_cthelper(skb, ct, ctinfo); +} + static bool nf_conntrack_get_tuple_skb(struct nf_conntrack_tuple *dst_tuple, const struct sk_buff *skb) { From 703acd70f2496537457186211c2f03e792409e68 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 24 May 2020 21:04:42 +0200 Subject: [PATCH 5/5] netfilter: nfnetlink_cthelper: unbreak userspace helper support Restore helper data size initialization and fix memcopy of the helper data size. Fixes: 157ffffeb5dc ("netfilter: nfnetlink_cthelper: reject too large userspace allocation requests") Reviewed-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nfnetlink_cthelper.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nfnetlink_cthelper.c b/net/netfilter/nfnetlink_cthelper.c index a5f294aa8e4c..5b0d0a77379c 100644 --- a/net/netfilter/nfnetlink_cthelper.c +++ b/net/netfilter/nfnetlink_cthelper.c @@ -103,7 +103,7 @@ nfnl_cthelper_from_nlattr(struct nlattr *attr, struct nf_conn *ct) if (help->helper->data_len == 0) return -EINVAL; - nla_memcpy(help->data, nla_data(attr), sizeof(help->data)); + nla_memcpy(help->data, attr, sizeof(help->data)); return 0; } @@ -240,6 +240,7 @@ nfnl_cthelper_create(const struct nlattr * const tb[], ret = -ENOMEM; goto err2; } + helper->data_len = size; helper->flags |= NF_CT_HELPER_F_USERSPACE; memcpy(&helper->tuple, tuple, sizeof(struct nf_conntrack_tuple));