linux/net/ipv6
Eric Dumazet f4dca95fc0 tcp: reduce accepted window in NEW_SYN_RECV state
Jason commit made checks against ACK sequence less strict
and can be exploited by attackers to establish spoofed flows
with less probes.

Innocent users might use tcp_rmem[1] == 1,000,000,000,
or something more reasonable.

An attacker can use a regular TCP connection to learn the server
initial tp->rcv_wnd, and use it to optimize the attack.

If we make sure that only the announced window (smaller than 65535)
is used for ACK validation, we force an attacker to use
65537 packets to complete the 3WHS (assuming server ISN is unknown)

Fixes: 378979e94e ("tcp: remove 64 KByte limit for initial tp->rcv_wnd value")
Link: https://datatracker.ietf.org/meeting/119/materials/slides-119-tcpm-ghost-acks-00
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://lore.kernel.org/r/20240523130528.60376-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-27 16:47:23 -07:00
..
ila ipv6: introduce dst_rt6_info() helper 2024-04-29 13:32:01 +01:00
netfilter netfilter: use NF_DROP instead of -NF_DROP 2024-05-06 16:29:21 +02:00
addrconf.c net: ipv{6,4}: Remove the now superfluous sentinel elements from ctl_table array 2024-05-03 13:29:42 +01:00
addrconf_core.c ipv6: Ensure natural alignment of const ipv6 loopback and router addresses 2024-01-30 12:43:18 +01:00
addrlabel.c ipv6: remove RTNL protection from ip6addrlbl_dump() 2024-04-08 11:01:05 +01:00
af_inet6.c net: introduce include/net/rps.h 2024-03-07 21:12:43 -08:00
ah6.c net: fill in MODULE_DESCRIPTION()s for ipv6 modules 2024-02-09 14:12:01 -08:00
anycast.c ipv6: anycast: use call_rcu_hurry() in aca_put() 2024-05-01 11:46:21 +01:00
calipso.c netlabel: remove impossible return value in netlbl_bitmap_walk 2024-02-28 19:37:34 -08:00
datagram.c ipv6: annotate data-races around np->ucast_oif 2023-12-11 10:59:17 +00:00
esp6.c ipsec-next-2024-05-03 2024-05-06 19:14:56 -07:00
esp6_offload.c xfrm: Support GRO for IPv6 ESP in UDP encapsulation 2023-10-06 07:31:14 +02:00
exthdrs.c net: ipv6: exthdrs: get rid of ipv6_skb_net() 2024-03-11 15:15:08 -07:00
exthdrs_core.c
exthdrs_offload.c net: gso: add HBH extension header offload support 2024-01-05 08:11:49 -08:00
fib6_notifier.c
fib6_rules.c ipv6: fib6_rules: avoid possible NULL dereference in fib6_rule_action() 2024-05-08 18:50:53 -07:00
fou6.c
icmp.c net: ipv{6,4}: Remove the now superfluous sentinel elements from ctl_table array 2024-05-03 13:29:42 +01:00
inet6_connection_sock.c net: implement lockless SO_PRIORITY 2023-10-01 19:09:54 +01:00
inet6_hashtables.c tcp: get rid of twsk_unique() 2024-05-09 20:25:55 -07:00
ioam6.c ipv6/addrconf: annotate data-races around devconf fields (II) 2024-03-01 08:42:33 +00:00
ioam6_iptunnel.c netlink: make range pointers in policies const 2023-10-26 16:24:09 -07:00
ip6_checksum.c
ip6_fib.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-04-11 14:23:47 -07:00
ip6_flowlabel.c ipv6: move np->repflow to atomic flags 2023-09-15 10:33:48 +01:00
ip6_gre.c net: ip6_gre: Remove generic .ndo_get_stats64 2024-04-15 11:32:13 +01:00
ip6_icmp.c
ip6_input.c ipv6/addrconf: annotate data-races around devconf fields (II) 2024-03-01 08:42:33 +00:00
ip6_offload.c net: gro: initialize network_offset in network layer 2024-05-27 16:46:59 -07:00
ip6_offload.h
ip6_output.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-05-09 10:01:01 -07:00
ip6_tunnel.c net: annotate writes on dev->mtu from ndo_change_mtu() 2024-05-07 16:19:14 -07:00
ip6_udp_tunnel.c net: fill in MODULE_DESCRIPTION()s for ipv6 modules 2024-02-09 14:12:01 -08:00
ip6_vti.c net: annotate writes on dev->mtu from ndo_change_mtu() 2024-05-07 16:19:14 -07:00
ip6mr.c ipv6: introduce dst_rt6_info() helper 2024-04-29 13:32:01 +01:00
ipcomp6.c
ipv6_sockglue.c inet: Add getsockopt support for IP_ROUTER_ALERT and IPV6_ROUTER_ALERT 2024-03-06 12:37:06 +00:00
Kconfig ipv6: fix indentation of a config attribute 2023-08-16 10:03:08 +01:00
Makefile net/tcp: Introduce TCP_AO setsockopt()s 2023-10-27 10:35:44 +01:00
mcast.c ipv6/addrconf: annotate data-races around devconf fields (II) 2024-03-01 08:42:33 +00:00
mcast_snoop.c
mip6.c net: fill in MODULE_DESCRIPTION()s for ipv6 modules 2024-02-09 14:12:01 -08:00
ndisc.c ipv6: introduce dst_rt6_info() helper 2024-04-29 13:32:01 +01:00
netfilter.c xfrm: pass struct net to xfrm_decode_session wrappers 2023-10-06 08:31:53 +02:00
output_core.c ipv6: annotate data-races around cnf.hop_limit 2024-03-01 08:42:31 +00:00
ping.c ipv6: introduce dst_rt6_info() helper 2024-04-29 13:32:01 +01:00
proc.c net: fix IPSTATS_MIB_OUTPKGS increment in OutForwDatagrams. 2023-10-20 12:01:00 +01:00
protocol.c
raw.c ipv6: introduce dst_rt6_info() helper 2024-04-29 13:32:01 +01:00
reassembly.c net: ipv6: fix wrong start position when receive hop-by-hop fragment 2024-05-10 10:04:06 +01:00
route.c net/ipv6: Fix route deleting failure when metric equals 0 2024-05-16 19:31:15 -07:00
rpl.c
rpl_iptunnel.c ipv6: rpl: Remove redundant skb_dst_drop(). 2023-07-12 17:12:29 -07:00
seg6.c ipv6: sr: fix invalid unregister error path 2024-05-10 19:27:46 -07:00
seg6_hmac.c ipv6: sr: fix memleak in seg6_hmac_init_algo 2024-05-21 13:16:25 +02:00
seg6_iptunnel.c ipv6: sr: fix missing sk_buff release in seg6_input_core 2024-05-20 11:36:34 +01:00
seg6_local.c seg6: add NEXT-C-SID support for SRv6 End.X behavior 2023-08-15 18:51:47 -07:00
sit.c ip_tunnel: convert __be16 tunnel flags to bitmaps 2024-04-01 10:49:28 +01:00
syncookies.c tcp: annotate data-races around tp->window_clamp 2024-04-05 22:32:37 -07:00
sysctl_net_ipv6.c net: ipv{6,4}: Remove the now superfluous sentinel elements from ctl_table array 2024-05-03 13:29:42 +01:00
tcp_ao.c net/tcp: Wire up l3index to TCP-AO 2023-10-27 10:35:46 +01:00
tcp_ipv6.c tcp: reduce accepted window in NEW_SYN_RECV state 2024-05-27 16:47:23 -07:00
tcpv6_offload.c net: gro: use cb instead of skb->network_header 2024-05-13 14:44:06 -07:00
tunnel6.c net: fill in MODULE_DESCRIPTION()s for ipv6 modules 2024-02-09 14:12:01 -08:00
udp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-05-02 12:06:25 -07:00
udp_impl.h
udp_offload.c net: gro: fix udp bad offset in socket lookup by adding {inner_}network_offset to napi_gro_cb 2024-05-02 11:02:48 +02:00
udplite.c udplite: remove UDPLITE_BIT 2023-09-14 16:16:36 +02:00
xfrm6_input.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-05-09 10:01:01 -07:00
xfrm6_output.c ipv6: drop feature RTAX_FEATURE_ALLFRAG 2023-10-25 18:04:29 -07:00
xfrm6_policy.c net: ipv{6,4}: Remove the now superfluous sentinel elements from ctl_table array 2024-05-03 13:29:42 +01:00
xfrm6_protocol.c
xfrm6_state.c
xfrm6_tunnel.c ipsec-next-2024-03-06 2024-03-08 10:56:05 +00:00