linux/net/ipv4
Neal Cardwell 18ded910b5 tcp: fix to update snd_wl1 in bulk receiver fast path
In the header prediction fast path for a bulk data receiver, if no
data is newly acknowledged then we do not call tcp_ack() and do not
call tcp_ack_update_window(). This means that a bulk receiver that
receives large amounts of data can have the incoming sequence numbers
wrap, so that the check in tcp_may_update_window fails:
   after(ack_seq, tp->snd_wl1)

If the incoming receive windows are zero in this state, and then the
connection that was a bulk data receiver later wants to send data,
that connection can find itself persistently rejecting the window
updates in incoming ACKs. This means the connection can persistently
fail to discover that the receive window has opened, which in turn
means that the connection is unable to send anything, and the
connection's sending process can get permanently "stuck".

The fix is to update snd_wl1 in the header prediction fast path for a
bulk data receiver, so that it keeps up and does not see wrapping
problems.

This fix is based on a very nice and thorough analysis and diagnosis
by Apollon Oikonomopoulos (see link below).

This is a stable candidate but there is no Fixes tag here since the
bug predates current git history. Just for fun: looks like the bug
dates back to when header prediction was added in Linux v2.1.8 in Nov
1996. In that version tcp_rcv_established() was added, and the code
only updates snd_wl1 in tcp_ack(), and in the new "Bulk data transfer:
receiver" code path it does not call tcp_ack(). This fix seems to
apply cleanly at least as far back as v3.2.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reported-by: Apollon Oikonomopoulos <apoikos@dmesg.gr>
Tested-by: Apollon Oikonomopoulos <apoikos@dmesg.gr>
Link: https://www.spinics.net/lists/netdev/msg692430.html
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20201022143331.1887495-1-ncardwell.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-22 12:26:57 -07:00
..
bpfilter net: Revert "net: optimize the sockptr_t for unified kernel/user address spaces" 2020-08-10 12:06:44 -07:00
netfilter netfilter: nf_log: missing vlan offload tag and proto 2020-10-14 01:25:14 +02:00
af_inet.c io_uring: allow tcp ancillary data for __sys_recvmsg_sock() 2020-08-24 16:16:06 -07:00
ah4.c inet: Use fallthrough; 2020-03-12 15:55:00 -07:00
arp.c inet: Use fallthrough; 2020-03-12 15:55:00 -07:00
bpf_tcp_ca.c bpf: Change bpf_sk_storage_*() to accept ARG_PTR_TO_BTF_ID_SOCK_COMMON 2020-09-25 13:58:01 -07:00
cipso_ipv4.c cipso: fix 'audit_secid' kernel-doc warning in cipso_ipv4.c 2020-09-08 20:03:36 -07:00
datagram.c inet: stop leaking jiffies on the wire 2019-11-01 14:57:52 -07:00
devinet.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-31 17:48:46 -07:00
esp4_offload.c net: Add MODULE_DESCRIPTION entries to network modules 2020-06-20 21:33:57 -07:00
esp4.c ESP: Export esp_output_fill_trailer function 2020-02-19 13:52:32 +01:00
fib_frontend.c ipv4: Initialize flowi4_multipath_hash in data path 2020-09-14 14:54:56 -07:00
fib_lookup.h net: add net available in build_state 2020-03-29 22:30:57 -07:00
fib_notifier.c net: fib_notifier: propagate extack down to the notifier block callback 2019-10-04 11:10:56 -07:00
fib_rules.c fib: use indirect call wrappers in the most common fib_rules_ops 2020-07-28 17:42:31 -07:00
fib_semantics.c net: Fix the arp error in some cases 2020-06-18 20:21:51 -07:00
fib_trie.c ipv4: Silence suspicious RCU usage warning 2020-08-26 15:58:48 -07:00
fou.c genetlink: move to smaller ops wherever possible 2020-10-02 19:11:11 -07:00
gre_demux.c gre: fix uninit-value in __iptunnel_pull_header 2020-03-08 21:25:37 -07:00
gre_offload.c net: gre: recompute gre csum for sctp over gre tunnels 2020-08-03 15:29:44 -07:00
icmp.c icmp: randomize the global rate limiter 2020-10-16 16:47:09 -07:00
igmp.c ip*_mc_gsfget(): lift copyout of struct group_filter into callers 2020-05-20 20:31:27 -04:00
inet_connection_sock.c inet: remove icsk_ack.blocked 2020-09-30 14:21:30 -07:00
inet_diag.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-09-22 16:45:34 -07:00
inet_fragment.c inet: frags: re-introduce skb coalescing for local delivery 2019-08-08 15:55:10 -07:00
inet_hashtables.c net: ipv4: remove unused arg exact_dif in compute_score 2020-08-31 13:08:29 -07:00
inet_timewait_sock.c
inetpeer.c inetpeer: fix data-race in inet_putpeer / inet_putpeer 2019-11-07 16:15:56 -08:00
ip_forward.c ipv4: Revert removal of rt_uses_gateway 2019-09-20 18:23:33 -07:00
ip_fragment.c inet: frags: re-introduce skb coalescing for local delivery 2019-08-08 15:55:10 -07:00
ip_gre.c ip_gre: set dev->hard_header_len and dev->needed_headroom properly 2020-10-13 18:35:29 -07:00
ip_input.c bpf: Add socket assign support 2020-03-30 13:45:04 -07:00
ip_options.c net: clean up codestyle for net/ipv4 2020-08-25 06:28:02 -07:00
ip_output.c networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
ip_sockglue.c net: Remove duplicated midx check against 0 2020-08-25 06:23:59 -07:00
ip_tunnel_core.c iptunnel: use new function dev_fetch_sw_netstats 2020-10-13 17:33:49 -07:00
ip_tunnel.c ipv4: use dev_sw_netstats_rx_add() 2020-10-06 06:23:21 -07:00
ip_vti.c ipv4: use dev_sw_netstats_rx_add() 2020-10-06 06:23:21 -07:00
ipcomp.c ipcomp: assign if_id to child tunnel from parent tunnel 2020-07-09 12:55:37 +02:00
ipconfig.c Documentation: nfsroot.rst: Fix references to nfsroot.rst 2020-03-02 13:11:46 -07:00
ipip.c net: ipip: implement header_ops->parse_protocol for AF_PACKET 2020-06-30 12:29:39 -07:00
ipmr_base.c net: fib_notifier: propagate extack down to the notifier block callback 2019-10-04 11:10:56 -07:00
ipmr.c ipmr: Use full VIF ID in netlink cache reports 2020-09-10 12:25:51 -07:00
Kconfig net: ipv4: remove duplicate "the the" phrase in Kconfig text 2020-08-18 16:02:16 -07:00
Makefile udp_tunnel: add central NIC RX port offload infrastructure 2020-07-10 13:54:00 -07:00
metrics.c
netfilter.c
netlink.c
nexthop.c nexthop: Fix performance regression in nexthop deletion 2020-10-19 20:07:15 -07:00
ping.c net: clean up codestyle 2020-08-31 12:33:34 -07:00
proc.c tcp: skip DSACKs with dubious sequence ranges 2020-09-24 20:15:45 -07:00
protocol.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
raw_diag.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-12 22:34:48 -07:00
raw.c networking changes for the 5.10 merge window 2020-10-15 18:42:13 -07:00
route.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-10-15 12:43:21 -07:00
syncookies.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-10-05 18:40:01 -07:00
sysctl_net_ipv4.c tcp: reflect tos value received in SYN to the socket 2020-09-10 13:15:40 -07:00
tcp_bbr.c tcp_bbr: improve arithmetic division in bbr_update_bw() 2020-01-21 10:45:49 +01:00
tcp_bic.c tcp: fix stretch ACK bugs in BIC 2020-03-16 18:26:54 -07:00
tcp_bpf.c net: sk_msg: Simplify sk_psock initialization 2020-08-21 15:16:11 -07:00
tcp_cdg.c
tcp_cong.c tcp: Simplify tcp_set_congestion_control() load=false case 2020-09-10 20:53:01 -07:00
tcp_cubic.c tcp_cubic: fix spurious HYSTART_DELAY exit upon drop in min RTT 2020-06-25 16:08:47 -07:00
tcp_dctcp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tcp_dctcp.h
tcp_diag.c inet_diag: Move the INET_DIAG_REQ_BYTECODE nlattr to cb->data 2020-02-27 18:50:19 -08:00
tcp_fastopen.c bpf: tcp: Add bpf_skops_established() 2020-08-24 14:35:00 -07:00
tcp_highspeed.c Replace HTTP links with HTTPS ones: IPv* 2020-07-06 13:23:03 -07:00
tcp_htcp.c Replace HTTP links with HTTPS ones: IPv* 2020-07-06 13:23:03 -07:00
tcp_hybla.c
tcp_illinois.c
tcp_input.c tcp: fix to update snd_wl1 in bulk receiver fast path 2020-10-22 12:26:57 -07:00
tcp_ipv4.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-10-08 15:44:50 -07:00
tcp_lp.c
tcp_metrics.c genetlink: move to smaller ops wherever possible 2020-10-02 19:11:11 -07:00
tcp_minisocks.c bpf: tcp: Do not limit cb_flags when creating child sk from listen sk 2020-10-02 11:34:48 -07:00
tcp_nv.c
tcp_offload.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tcp_output.c tcp: add exponential backoff in __tcp_send_ack() 2020-09-30 14:21:30 -07:00
tcp_rate.c
tcp_recovery.c tcp: move tcp_mark_skb_lost 2020-09-25 17:17:14 -07:00
tcp_scalable.c net: ipv4: delete repeated words 2020-08-24 17:31:20 -07:00
tcp_timer.c inet: remove icsk_ack.blocked 2020-09-30 14:21:30 -07:00
tcp_ulp.c bpf: sockmap: Only check ULP for TCP sockets 2020-03-09 22:34:58 +01:00
tcp_vegas.c tcp: use semicolons rather than commas to separate statements 2020-10-13 17:11:52 -07:00
tcp_vegas.h
tcp_veno.c Replace HTTP links with HTTPS ones: IPv* 2020-07-06 13:23:03 -07:00
tcp_westwood.c
tcp_yeah.c tcp: fix stretch ACK bugs in Yeah 2020-03-16 18:26:55 -07:00
tcp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-10-05 18:40:01 -07:00
tunnel4.c tunnel4: add cb_handler to struct xfrm_tunnel 2020-07-09 12:51:36 +02:00
udp_bpf.c net: sk_msg: Simplify sk_psock initialization 2020-08-21 15:16:11 -07:00
udp_diag.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-12 22:34:48 -07:00
udp_impl.h net: pass a sockptr_t into ->setsockopt 2020-07-24 15:41:54 -07:00
udp_offload.c udp: initialize is_flist with 0 in udp_gro_receive 2020-03-30 10:35:03 -07:00
udp_tunnel_core.c udp_tunnel: add central NIC RX port offload infrastructure 2020-07-10 13:54:00 -07:00
udp_tunnel_nic.c udp_tunnel: add the ability to share port tables 2020-09-28 12:50:12 -07:00
udp_tunnel_stub.c udp_tunnel: add central NIC RX port offload infrastructure 2020-07-10 13:54:00 -07:00
udp.c net: ipv4: delete repeated words 2020-08-24 17:31:20 -07:00
udplite.c net/ipv4: remove compat_ip_{get,set}sockopt 2020-07-19 18:16:41 -07:00
xfrm4_input.c xfrm: state: remove extract_input indirection from xfrm_state_afinfo 2020-05-06 09:40:08 +02:00
xfrm4_output.c xfrm: fix unused variable warning if CONFIG_NETFILTER=n 2020-05-11 15:12:27 +02:00
xfrm4_policy.c net: add bool confirm_neigh parameter for dst_ops.update_pmtu 2019-12-24 22:28:54 -08:00
xfrm4_protocol.c xfrm: add route lookup to xfrm4_rcv_encap 2019-12-09 09:59:07 +01:00
xfrm4_state.c xfrm: remove output_finish indirection from xfrm_state_afinfo 2020-05-06 09:40:08 +02:00
xfrm4_tunnel.c xfrm: remove type and offload_type map from xfrm_state_afinfo 2019-06-06 08:34:50 +02:00