linux/net/ipv4
Xin Long 22600596b6 ipv4: give an IPv4 dev to blackhole_netdev
After commit 8d7017fd62 ("blackhole_netdev: use blackhole_netdev to
invalidate dst entries"), blackhole_netdev was introduced to invalidate
dst cache entries on the TX path whenever the cache times out or is
flushed.

When two UDP sockets (sk1 and sk2) send messages to the same destination
simultaneously, they are using the same dst cache. If the dst cache is
invalidated on one path (sk2) while the other (sk1) is still transmitting,
sk1 may try to use the invalid dst entry.

         CPU1                   CPU2

      udp_sendmsg(sk1)       udp_sendmsg(sk2)
      udp_send_skb()
      ip_output()
                                             <--- dst timeout or flushed
                             dst_dev_put()
      ip_finish_output2()
      ip_neigh_for_gw()

This results in a scenario where ip_neigh_for_gw() returns -EINVAL because
blackhole_dev lacks an in_dev, which is needed to initialize the neigh in
arp_constructor(). This error is then propagated back to userspace,
breaking the UDP application.

The patch fixes this issue by assigning an in_dev to blackhole_dev for
IPv4, similar to what was done for IPv6 in commit e5f80fcf86 ("ipv6:
give an IPv6 dev to blackhole_netdev"). This ensures that even when the
dst entry is invalidated with blackhole_dev, it will not fail to create
the neigh entry.

As devinet_init() is called ealier than blackhole_netdev_init() in system
booting, it can not assign the in_dev to blackhole_dev in devinet_init().
As Paolo suggested, add a separate late_initcall() in devinet.c to ensure
inet_blackhole_dev_init() is called after blackhole_netdev_init().

Fixes: 8d7017fd62 ("blackhole_netdev: use blackhole_netdev to invalidate dst entries")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/3000792d45ca44e16c785ebe2b092e610e5b3df1.1728499633.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-10-11 15:36:12 -07:00
..
netfilter netfilter: fib: check correct rtable in vrf setups 2024-10-09 23:30:31 +02:00
af_inet.c net: gro: initialize network_offset in network layer 2024-05-27 16:46:59 -07:00
ah4.c net: fill in MODULE_DESCRIPTION()s for ipv4 modules 2024-02-09 14:12:02 -08:00
arp.c arp: Convert ioctl(SIOCGARP) to RCU. 2024-05-01 18:37:07 -07:00
bpf_tcp_ca.c bpf: Check unsupported ops from the bpf_struct_ops's cfi_stubs 2024-07-29 12:54:13 -07:00
cipso_ipv4.c move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
datagram.c ipv4: Set the routing scope properly in ip_route_output_ports(). 2024-02-12 17:33:05 -08:00
devinet.c ipv4: give an IPv4 dev to blackhole_netdev 2024-10-11 15:36:12 -07:00
esp4_offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-07-15 13:19:17 -07:00
esp4.c net: support non paged skb frags 2024-09-11 20:44:31 -07:00
fib_frontend.c ipv4: Unmask upper DSCP bits in fib_compute_spec_dst() 2024-08-22 16:59:57 -07:00
fib_lookup.h
fib_notifier.c
fib_rules.c ipv4: fib_rules: Add DSCP selector support 2024-09-13 21:15:44 -07:00
fib_semantics.c ipv4: delete redundant judgment statements 2024-08-23 14:27:45 +01:00
fib_trie.c ipv4: Centralize TOS matching 2024-08-20 14:57:08 +02:00
fou_bpf.c ip_tunnel: convert __be16 tunnel flags to bitmaps 2024-04-01 10:49:28 +01:00
fou_core.c fou: fix initialization of grc 2024-09-09 17:21:47 -07:00
fou_nl.c net: ynl: prefix uAPI header include with uapi/ 2023-05-26 10:30:14 +01:00
fou_nl.h net: ynl: prefix uAPI header include with uapi/ 2023-05-26 10:30:14 +01:00
gre_demux.c ip_tunnel: convert __be16 tunnel flags to bitmaps 2024-04-01 10:49:28 +01:00
gre_offload.c net: gro: rename skb_gro_header_hard() 2024-03-05 13:30:11 +01:00
icmp.c ipv4: icmp: Unmask upper DSCP bits in icmp_reply() 2024-09-09 14:14:53 +01:00
igmp.c ipv4: Set scope explicitly in ip_route_output(). 2024-04-08 13:20:51 +01:00
inet_connection_sock.c slab updates for 6.12 2024-09-18 08:53:53 +02:00
inet_diag.c tcp: remove volatile qualifier on tw_substate 2024-08-28 17:08:16 -07:00
inet_fragment.c net: Rename mono_delivery_time to tstamp_type for scalabilty 2024-05-23 14:14:23 -07:00
inet_hashtables.c inet: constify 'struct net' parameter of various lookup helpers 2024-08-05 16:22:45 -07:00
inet_timewait_sock.c tcp: move inet_twsk_schedule helper out of header 2024-06-10 11:54:18 +01:00
inetpeer.c net: ipv4: Simplify the allocation of slab caches in inet_initpeers 2024-01-31 16:39:42 -08:00
ip_forward.c net: fix IPSTATS_MIB_OUTFORWDATAGRAMS increment after fragment check 2023-10-13 09:58:45 -07:00
ip_fragment.c net: Rename mono_delivery_time to tstamp_type for scalabilty 2024-05-23 14:14:23 -07:00
ip_gre.c ipv4: ip_gre: Fix drops of small packets in ipgre_xmit 2024-10-01 13:04:03 +02:00
ip_input.c net/ipv4: make use of the helper macro LIST_HEAD() 2024-09-06 18:10:21 -07:00
ip_options.c move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
ip_output.c ipv4: Unmask upper DSCP bits in __ip_queue_xmit() 2024-09-04 16:57:11 -07:00
ip_sockglue.c inet: Add getsockopt support for IP_ROUTER_ALERT and IPV6_ROUTER_ALERT 2024-03-06 12:37:06 +00:00
ip_tunnel_core.c ip_tunnel: convert __be16 tunnel flags to bitmaps 2024-04-01 10:49:28 +01:00
ip_tunnel.c ipv4: ip_tunnel: Unmask upper DSCP bits in ip_tunnel_xmit() 2024-09-09 14:14:53 +01:00
ip_vti.c netdev_features: convert NETIF_F_LLTX to dev->lltx 2024-09-03 11:36:43 +02:00
ipcomp.c
ipconfig.c net: ipconfig: move ic_nameservers_fallback into #ifdef block 2023-05-22 11:17:55 +01:00
ipip.c netdev_features: convert NETIF_F_LLTX to dev->lltx 2024-09-03 11:36:43 +02:00
ipmr_base.c
ipmr.c ipv4: ipmr: Unmask upper DSCP bits in ipmr_queue_xmit() 2024-09-04 16:57:11 -07:00
Kconfig net/tcp: Expand goo.gl link 2024-07-30 18:35:12 -07:00
Makefile bpfilter: remove bpfilter 2024-01-04 10:23:10 -08:00
metrics.c net: remove NULL-pointer net parameter in ip_metrics_convert 2024-06-05 10:06:00 +01:00
netfilter.c ipv4: netfilter: Unmask upper DSCP bits in ip_route_me_harder() 2024-09-09 14:14:53 +01:00
netlink.c
nexthop.c net: nexthop: delete redundant judgment statements 2024-08-23 14:27:45 +01:00
ping.c ping: use sk_skb_reason_drop to free rx packets 2024-06-19 12:44:22 +01:00
proc.c minmax: add a few more MIN_T/MAX_T users 2024-07-28 13:41:14 -07:00
protocol.c
raw_diag.c inet_diag: add module pointer to "struct inet_diag_handler" 2024-01-23 15:13:54 +01:00
raw.c net: raw: use sk_skb_reason_drop to free rx packets 2024-06-19 12:44:22 +01:00
route.c ipv4: Unmask upper DSCP bits when building flow key 2024-08-31 17:44:51 +01:00
syncookies.c tcp: use sk_skb_reason_drop to free rx packets 2024-06-19 12:44:22 +01:00
sysctl_net_ipv4.c icmp: icmp_msgs_per_sec and icmp_msgs_burst sysctls become per netns 2024-08-30 11:14:06 -07:00
tcp_ao.c net/tcp: Disable TCP-AO static key after RCU grace period 2024-08-04 13:21:50 +01:00
tcp_bbr.c tcp: Add new args for cong_control in tcp_congestion_ops 2024-05-02 16:26:56 -07:00
tcp_bic.c
tcp_bpf.c bpf-next-for-netdev 2024-09-12 20:22:44 -07:00
tcp_cdg.c
tcp_cong.c tcp: Replace strncpy() with strscpy() 2024-07-16 07:52:15 -07:00
tcp_cubic.c bpf: Remove CONFIG_X86 and CONFIG_DYNAMIC_FTRACE guard from the tcp-cc kfuncs 2024-03-28 18:31:40 -07:00
tcp_dctcp.c tcp: Fix shift-out-of-bounds in dctcp_update_alpha(). 2024-05-21 13:34:50 +02:00
tcp_dctcp.h
tcp_diag.c inet_diag: add module pointer to "struct inet_diag_handler" 2024-01-23 15:13:54 +01:00
tcp_fastopen.c net: use unrcu_pointer() helper 2024-06-06 11:52:52 +02:00
tcp_highspeed.c
tcp_htcp.c tcp: Use clamp() in htcp_alpha_update() 2024-08-06 12:16:25 -07:00
tcp_hybla.c
tcp_illinois.c
tcp_input.c tcp: fix TFO SYN_RECV to not zero retrans_stamp with retransmits out 2024-10-03 16:18:04 -07:00
tcp_ipv4.c tcp: RX path for devmem TCP 2024-09-11 20:44:32 -07:00
tcp_lp.c tcp: rename tcp_time_stamp() to tcp_time_stamp_ts() 2023-10-23 09:35:01 +01:00
tcp_metrics.c tcp_metrics: use netlink policy for IPv6 addr len validation 2024-08-19 17:42:57 -07:00
tcp_minisocks.c tcp: RX path for devmem TCP 2024-09-11 20:44:32 -07:00
tcp_nv.c
tcp_offload.c net: gso: fix tcp fraglist segmentation after pull from frag_list 2024-10-02 17:21:47 -07:00
tcp_output.c tcp: fix mptcp DSS corruption due to large pmtu xmit 2024-10-09 19:43:44 -07:00
tcp_plb.c
tcp_rate.c
tcp_recovery.c tcp: fix excessive TLP and RACK timeouts from HZ rounding 2023-10-17 17:25:42 -07:00
tcp_scalable.c
tcp_sigpool.c net/tcp_sigpool: Use nested-BH locking for sigpool_scratch. 2024-06-24 16:41:22 -07:00
tcp_timer.c mptcp: fallback to TCP after SYN+MPC drops 2024-09-11 15:57:50 -07:00
tcp_ulp.c
tcp_vegas.c
tcp_vegas.h
tcp_veno.c
tcp_westwood.c
tcp_yeah.c
tcp.c tcp: RX path for devmem TCP 2024-09-11 20:44:32 -07:00
tunnel4.c net: fill in MODULE_DESCRIPTION()s for ipv4 modules 2024-02-09 14:12:02 -08:00
udp_bpf.c bpf, sockmap: Fix an infinite loop error when len is 0 in tcp_bpf_recvmsg_parser() 2023-03-03 17:25:15 +01:00
udp_diag.c inet_diag: add module pointer to "struct inet_diag_handler" 2024-01-23 15:13:54 +01:00
udp_impl.h sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES) 2023-06-24 15:50:13 -07:00
udp_offload.c gso: fix udp gso fraglist segmentation after pull from frag_list 2024-10-02 17:29:31 -07:00
udp_tunnel_core.c ipv4: udp_tunnel: Unmask upper DSCP bits in udp_tunnel_dst_lookup() 2024-09-09 14:14:53 +01:00
udp_tunnel_nic.c udp_tunnel: Use flex array to simplify code 2023-10-03 11:39:34 +02:00
udp_tunnel_stub.c
udp.c ipv4: udp: Unmask upper DSCP bits during early demux 2024-08-22 16:59:58 -07:00
udplite.c udplite: remove UDPLITE_BIT 2023-09-14 16:16:36 +02:00
xfrm4_input.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2024-05-09 10:01:01 -07:00
xfrm4_output.c
xfrm4_policy.c net: ipv{6,4}: Remove the now superfluous sentinel elements from ctl_table array 2024-05-03 13:29:42 +01:00
xfrm4_protocol.c
xfrm4_state.c
xfrm4_tunnel.c net: fill in MODULE_DESCRIPTION()s for ipv4 modules 2024-02-09 14:12:02 -08:00