From fe337ac2839521b360f828b3ebd992d597b1ad16 Mon Sep 17 00:00:00 2001 From: Florian Westphal <fw@strlen.de> Date: Mon, 28 Apr 2014 21:07:31 +0200 Subject: netfilter: ctnetlink: don't add null bindings if no nat requested commit 0eba801b64cc8284d9024c7ece30415a2b981a72 tried to fix a race where nat initialisation can happen after ctnetlink-created conntrack has been created. However, it causes the nat module(s) to be loaded needlessly on systems that are not using NAT. Fortunately, we do not have to create null bindings in that case. conntracks injected via ctnetlink always have the CONFIRMED bit set, which prevents addition of the nat extension in nf_nat_ipv4/6_fn(). We only need to make sure that either no nat extension is added or that we've created both src and dst manips. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- net/netfilter/nf_conntrack_netlink.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index ccc46fa5edbc..58579634427d 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -1336,6 +1336,9 @@ ctnetlink_setup_nat(struct nf_conn *ct, const struct nlattr * const cda[]) #ifdef CONFIG_NF_NAT_NEEDED int ret; + if (!cda[CTA_NAT_DST] && !cda[CTA_NAT_SRC]) + return 0; + ret = ctnetlink_parse_nat_setup(ct, NF_NAT_MANIP_DST, cda[CTA_NAT_DST]); if (ret < 0) -- cgit v1.2.2 From 895162b1101b3ea5db08ca6822ae9672717efec0 Mon Sep 17 00:00:00 2001 From: Florian Westphal <fw@strlen.de> Date: Fri, 2 May 2014 15:32:16 +0200 Subject: netfilter: ipv4: defrag: set local_df flag on defragmented skb else we may fail to forward skb even if original fragments do fit outgoing link mtu: 1. remote sends 2k packets in two 1000 byte frags, DF set 2. we want to forward but only see '2k > mtu and DF set' 3. we then send icmp error saying that outgoing link is 1500 But original sender never sent a packet that would not fit the outgoing link. Setting local_df makes outgoing path test size vs. IPCB(skb)->frag_max_size, so we will still send the correct error in case the largest original size did not fit outgoing link mtu. Reported-by: Maxime Bizon <mbizon@freebox.fr> Suggested-by: Maxime Bizon <mbizon@freebox.fr> Fixes: 5f2d04f1f9 (ipv4: fix path MTU discovery with connection tracking) Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- net/ipv4/netfilter/nf_defrag_ipv4.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/ipv4/netfilter/nf_defrag_ipv4.c b/net/ipv4/netfilter/nf_defrag_ipv4.c index 12e13bd82b5b..f40f321b41fc 100644 --- a/net/ipv4/netfilter/nf_defrag_ipv4.c +++ b/net/ipv4/netfilter/nf_defrag_ipv4.c @@ -22,7 +22,6 @@ #endif #include <net/netfilter/nf_conntrack_zones.h> -/* Returns new sk_buff, or NULL */ static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user) { int err; @@ -33,8 +32,10 @@ static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user) err = ip_defrag(skb, user); local_bh_enable(); - if (!err) + if (!err) { ip_send_check(ip_hdr(skb)); + skb->local_df = 1; + } return err; } -- cgit v1.2.2 From ecd15dd7e45f3683fa8142b9f2c015dfaa0c243d Mon Sep 17 00:00:00 2001 From: Denys Fedoryshchenko <nuclearcat@nuclearcat.com> Date: Sun, 4 May 2014 13:35:37 +0200 Subject: netfilter: nfnetlink: Fix use after free when it fails to process batch This bug manifests when calling the nft command line tool without nf_tables kernel support. kernel message: [ 44.071555] Netfilter messages via NETLINK v0.30. [ 44.072253] BUG: unable to handle kernel NULL pointer dereference at 0000000000000119 [ 44.072264] IP: [<ffffffff8171db1f>] netlink_getsockbyportid+0xf/0x70 [ 44.072272] PGD 7f2b74067 PUD 7f2b73067 PMD 0 [ 44.072277] Oops: 0000 [#1] SMP [...] [ 44.072369] Call Trace: [ 44.072373] [<ffffffff8171fd81>] netlink_unicast+0x91/0x200 [ 44.072377] [<ffffffff817206c9>] netlink_ack+0x99/0x110 [ 44.072381] [<ffffffffa004b951>] nfnetlink_rcv+0x3c1/0x408 [nfnetlink] [ 44.072385] [<ffffffff8171fde3>] netlink_unicast+0xf3/0x200 [ 44.072389] [<ffffffff817201ef>] netlink_sendmsg+0x2ff/0x740 [ 44.072394] [<ffffffff81044752>] ? __mmdrop+0x62/0x90 [ 44.072398] [<ffffffff816dafdb>] sock_sendmsg+0x8b/0xc0 [ 44.072403] [<ffffffff812f1af5>] ? copy_user_enhanced_fast_string+0x5/0x10 [ 44.072406] [<ffffffff816dbb6c>] ? move_addr_to_kernel+0x2c/0x50 [ 44.072410] [<ffffffff816db423>] ___sys_sendmsg+0x3c3/0x3d0 [ 44.072415] [<ffffffff811301ba>] ? handle_mm_fault+0xa9a/0xc60 [ 44.072420] [<ffffffff811362d6>] ? mmap_region+0x166/0x5a0 [ 44.072424] [<ffffffff817da84c>] ? __do_page_fault+0x1dc/0x510 [ 44.072428] [<ffffffff812b8b2c>] ? apparmor_capable+0x1c/0x60 [ 44.072435] [<ffffffff817d6e9a>] ? _raw_spin_unlock_bh+0x1a/0x20 [ 44.072439] [<ffffffff816dfc86>] ? release_sock+0x106/0x150 [ 44.072443] [<ffffffff816dc212>] __sys_sendmsg+0x42/0x80 [ 44.072446] [<ffffffff816dc262>] SyS_sendmsg+0x12/0x20 [ 44.072450] [<ffffffff817df616>] system_call_fastpath+0x1a/0x1f Signed-off-by: Denys Fedoryshchenko <nuclearcat@nuclearcat.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- net/netfilter/nfnetlink.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index e009087620e3..23ef77c60fff 100644 --- a/net/netfilter/nfnetlink.c +++ b/net/netfilter/nfnetlink.c @@ -256,15 +256,15 @@ replay: #endif { nfnl_unlock(subsys_id); - kfree_skb(nskb); - return netlink_ack(skb, nlh, -EOPNOTSUPP); + netlink_ack(skb, nlh, -EOPNOTSUPP); + return kfree_skb(nskb); } } if (!ss->commit || !ss->abort) { nfnl_unlock(subsys_id); - kfree_skb(nskb); - return netlink_ack(skb, nlh, -EOPNOTSUPP); + netlink_ack(skb, nlh, -EOPNOTSUPP); + return kfree_skb(skb); } while (skb->len >= nlmsg_total_size(0)) { -- cgit v1.2.2 From 7c3d5ab1f35f5475b1a1fbe74143683cfc092d33 Mon Sep 17 00:00:00 2001 From: Vasily Averin <vvs@parallels.com> Date: Sat, 3 May 2014 03:14:04 +0400 Subject: ipv4: fix "conntrack zones" support for defrag user check in ip_expire Defrag user check in ip_expire was not updated after adding support for "conntrack zones". This bug manifests as a RFC violation, since the router will send the icmp time exceeeded message when using conntrack zones. Signed-off-by: Vasily Averin <vvs@openvz.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- net/ipv4/ip_fragment.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c index c10a3ce5cbff..ed32313e307c 100644 --- a/net/ipv4/ip_fragment.c +++ b/net/ipv4/ip_fragment.c @@ -232,8 +232,9 @@ static void ip_expire(unsigned long arg) * "Fragment Reassembly Timeout" message, per RFC792. */ if (qp->user == IP_DEFRAG_AF_PACKET || - (qp->user == IP_DEFRAG_CONNTRACK_IN && - skb_rtable(head)->rt_type != RTN_LOCAL)) + ((qp->user >= IP_DEFRAG_CONNTRACK_IN) && + (qp->user <= __IP_DEFRAG_CONNTRACK_IN_END) && + (skb_rtable(head)->rt_type != RTN_LOCAL))) goto out_rcu_unlock; -- cgit v1.2.2 From aff09ce303f83bd370772349238482ae422a2341 Mon Sep 17 00:00:00 2001 From: Vasily Averin <vvs@parallels.com> Date: Mon, 5 May 2014 00:17:48 +0400 Subject: bridge: superfluous skb->nfct check in br_nf_dev_queue_xmit Currently bridge can silently drop ipv4 fragments. If node have loaded nf_defrag_ipv4 module but have no nf_conntrack_ipv4, br_nf_pre_routing defragments incoming ipv4 fragments but nfct check in br_nf_dev_queue_xmit does not allow re-fragment combined packet back, and therefore it is dropped in br_dev_queue_push_xmit without incrementing of any failcounters It seems the only way to hit the ip_fragment code in the bridge xmit path is to have a fragment list whose reassembled fragments go over the mtu. This only happens if nf_defrag is enabled. Thanks to Florian Westphal for providing feedback to clarify this. Defragmentation ipv4 is required not only in conntracks but at least in TPROXY target and socket match, therefore #ifdef is changed from NF_CONNTRACK_IPV4 to NF_DEFRAG_IPV4 Signed-off-by: Vasily Averin <vvs@openvz.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- net/bridge/br_netfilter.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index 80e1b0f60a30..2acf7fa1fec6 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -859,12 +859,12 @@ static unsigned int br_nf_forward_arp(const struct nf_hook_ops *ops, return NF_STOLEN; } -#if IS_ENABLED(CONFIG_NF_CONNTRACK_IPV4) +#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV4) static int br_nf_dev_queue_xmit(struct sk_buff *skb) { int ret; - if (skb->nfct != NULL && skb->protocol == htons(ETH_P_IP) && + if (skb->protocol == htons(ETH_P_IP) && skb->len + nf_bridge_mtu_reduction(skb) > skb->dev->mtu && !skb_is_gso(skb)) { if (br_parse_ip_options(skb)) -- cgit v1.2.2 From a8951d5814e1373807a94f79f7ccec7041325470 Mon Sep 17 00:00:00 2001 From: Sergey Popovich <popovich_sergei@mail.ru> Date: Thu, 8 May 2014 16:22:35 +0300 Subject: netfilter: Fix potential use after free in ip6_route_me_harder() Dst is released one line before we access it again with dst->error. Fixes: 58e35d147128 netfilter: ipv6: propagate routing errors from ip6_route_me_harder() Signed-off-by: Sergey Popovich <popovich_sergei@mail.ru> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- net/ipv6/netfilter.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c index 95f3f1da0d7f..d38e6a8d8b9f 100644 --- a/net/ipv6/netfilter.c +++ b/net/ipv6/netfilter.c @@ -30,13 +30,15 @@ int ip6_route_me_harder(struct sk_buff *skb) .daddr = iph->daddr, .saddr = iph->saddr, }; + int err; dst = ip6_route_output(net, skb->sk, &fl6); - if (dst->error) { + err = dst->error; + if (err) { IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); LIMIT_NETDEBUG(KERN_DEBUG "ip6_route_me_harder: No more route.\n"); dst_release(dst); - return dst->error; + return err; } /* Drop old route. */ -- cgit v1.2.2