From b515d2637276a3810d6595e10ab02c13bfd0b63a Mon Sep 17 00:00:00 2001 From: Sabrina Dubroca Date: Fri, 16 Apr 2021 11:27:59 +0200 Subject: xfrm: xfrm_state_mtu should return at least 1280 for ipv6 Jianwen reported that IPv6 Interoperability tests are failing in an IPsec case where one of the links between the IPsec peers has an MTU of 1280. The peer generates a packet larger than this MTU, the router replies with a "Packet too big" message indicating an MTU of 1280. When the peer tries to send another large packet, xfrm_state_mtu returns 1280 - ipsec_overhead, which causes ip6_setup_cork to fail with EINVAL. We can fix this by forcing xfrm_state_mtu to return IPV6_MIN_MTU when IPv6 is used. After going through IPsec, the packet will then be fragmented to obey the actual network's PMTU, just before leaving the host. Currently, TFC padding is capped to PMTU - overhead to avoid fragementation: after padding and encapsulation, we still fit within the PMTU. That behavior is preserved in this patch. Fixes: 91657eafb64b ("xfrm: take net hdr len into account for esp payload size calculation") Reported-by: Jianwen Ji Signed-off-by: Sabrina Dubroca Signed-off-by: Steffen Klassert --- net/ipv6/esp6.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv6') diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c index 727d791ed5e6..9d1327b36bd3 100644 --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -708,7 +708,7 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb) struct xfrm_dst *dst = (struct xfrm_dst *)skb_dst(skb); u32 padto; - padto = min(x->tfcpad, xfrm_state_mtu(x, dst->child_mtu_cached)); + padto = min(x->tfcpad, __xfrm_state_mtu(x, dst->child_mtu_cached)); if (skb->len < padto) esp.tfclen = padto - skb->len; } -- cgit v1.2.3 From a6e3f2985a80ef6a45a17d2d9d9151f17ea3ce07 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 21 Jun 2021 18:52:54 -0700 Subject: ip6_tunnel: fix GRE6 segmentation Commit 6c11fbf97e69 ("ip6_tunnel: add MPLS transmit support") moved assiging inner_ipproto down from ipxip6_tnl_xmit() to its callee ip6_tnl_xmit(). The latter is also used by GRE. Since commit 38720352412a ("gre: Use inner_proto to obtain inner header protocol") GRE had been depending on skb->inner_protocol during segmentation. It sets it in gre_build_header() and reads it in gre_gso_segment(). Changes to ip6_tnl_xmit() overwrite the protocol, resulting in GSO skbs getting dropped. Note that inner_protocol is a union with inner_ipproto, GRE uses the former while the change switched it to the latter (always setting it to just IPPROTO_GRE). Restore the original location of skb_set_inner_ipproto(), it is unclear why it was moved in the first place. Fixes: 6c11fbf97e69 ("ip6_tunnel: add MPLS transmit support") Signed-off-by: Jakub Kicinski Tested-by: Vadim Fedorenko Signed-off-by: David S. Miller --- net/ipv6/ip6_tunnel.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 288bafded998..28ca70af014a 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1239,8 +1239,6 @@ route_lookup: if (max_headroom > dev->needed_headroom) dev->needed_headroom = max_headroom; - skb_set_inner_ipproto(skb, proto); - err = ip6_tnl_encap(skb, t, &proto, fl6); if (err) return err; @@ -1377,6 +1375,8 @@ ipxip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6)) return -1; + skb_set_inner_ipproto(skb, protocol); + err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu, protocol); if (err != 0) { -- cgit v1.2.3 From bcc3f2a829b9edbe3da5fb117ee5a63686d31834 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 23 Jun 2021 08:27:00 -0700 Subject: ipv6: exthdrs: do not blindly use init_net I see no reason why max_dst_opts_cnt and max_hbh_opts_cnt are fetched from the initial net namespace. The other sysctls (max_dst_opts_len & max_hbh_opts_len) are in fact already using the current ns. Note: it is not clear why ipv6_destopt_rcv() use two ways to get to the netns : 1) dev_net(dst->dev) Originally used to increment IPSTATS_MIB_INHDRERRORS 2) dev_net(skb->dev) Tom used this variant in his patch. Maybe this calls to use ipv6_skb_net() instead ? Fixes: 47d3d7ac656a ("ipv6: Implement limits on Hop-by-Hop and Destination options") Signed-off-by: Eric Dumazet Cc: Tom Herbert Cc: Coco Li Signed-off-by: David S. Miller --- net/ipv6/exthdrs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index 56e479d158b7..6f7da8f3e2e5 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -306,7 +306,7 @@ fail_and_free: #endif if (ip6_parse_tlv(tlvprocdestopt_lst, skb, - init_net.ipv6.sysctl.max_dst_opts_cnt)) { + net->ipv6.sysctl.max_dst_opts_cnt)) { skb->transport_header += extlen; opt = IP6CB(skb); #if IS_ENABLED(CONFIG_IPV6_MIP6) @@ -1037,7 +1037,7 @@ fail_and_free: opt->flags |= IP6SKB_HOPBYHOP; if (ip6_parse_tlv(tlvprochopopt_lst, skb, - init_net.ipv6.sysctl.max_hbh_opts_cnt)) { + net->ipv6.sysctl.max_hbh_opts_cnt)) { skb->transport_header += extlen; opt = IP6CB(skb); opt->nhoff = sizeof(struct ipv6hdr); -- cgit v1.2.3 From 624085a31c1ad6a80b1e53f686bf6ee92abbf6e8 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 24 Jun 2021 03:07:20 -0700 Subject: ipv6: fix out-of-bound access in ip6_parse_tlv() First problem is that optlen is fetched without checking there is more than one byte to parse. Fix this by taking care of IPV6_TLV_PAD1 before fetching optlen (under appropriate sanity checks against len) Second problem is that IPV6_TLV_PADN checks of zero padding are performed before the check of remaining length. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Fixes: c1412fce7ecc ("net/ipv6/exthdrs.c: Strict PadN option checking") Signed-off-by: Eric Dumazet Cc: Paolo Abeni Cc: Tom Herbert Signed-off-by: David S. Miller --- net/ipv6/exthdrs.c | 27 +++++++++++++-------------- 1 file changed, 13 insertions(+), 14 deletions(-) (limited to 'net/ipv6') diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index 6f7da8f3e2e5..26882e165c9e 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -135,18 +135,23 @@ static bool ip6_parse_tlv(const struct tlvtype_proc *procs, len -= 2; while (len > 0) { - int optlen = nh[off + 1] + 2; - int i; + int optlen, i; - switch (nh[off]) { - case IPV6_TLV_PAD1: - optlen = 1; + if (nh[off] == IPV6_TLV_PAD1) { padlen++; if (padlen > 7) goto bad; - break; + off++; + len--; + continue; + } + if (len < 2) + goto bad; + optlen = nh[off + 1] + 2; + if (optlen > len) + goto bad; - case IPV6_TLV_PADN: + if (nh[off] == IPV6_TLV_PADN) { /* RFC 2460 states that the purpose of PadN is * to align the containing header to multiples * of 8. 7 is therefore the highest valid value. @@ -163,12 +168,7 @@ static bool ip6_parse_tlv(const struct tlvtype_proc *procs, if (nh[off + i] != 0) goto bad; } - break; - - default: /* Other TLV code so scan list */ - if (optlen > len) - goto bad; - + } else { tlv_count++; if (tlv_count > max_count) goto bad; @@ -188,7 +188,6 @@ static bool ip6_parse_tlv(const struct tlvtype_proc *procs, return false; padlen = 0; - break; } off += optlen; len -= optlen; -- cgit v1.2.3