linux/net
Ido Schimmel 0c51e12e21 ipv4: Invalidate neighbour for broadcast address upon address addition
In case user space sends a packet destined to a broadcast address when a
matching broadcast route is not configured, the kernel will create a
unicast neighbour entry that will never be resolved [1].

When the broadcast route is configured, the unicast neighbour entry will
not be invalidated and continue to linger, resulting in packets being
dropped.

Solve this by invalidating unresolved neighbour entries for broadcast
addresses after routes for these addresses are internally configured by
the kernel. This allows the kernel to create a broadcast neighbour entry
following the next route lookup.

Another possible solution that is more generic but also more complex is
to have the ARP code register a listener to the FIB notification chain
and invalidate matching neighbour entries upon the addition of broadcast
routes.

It is also possible to wave off the issue as a user space problem, but
it seems a bit excessive to expect user space to be that intimately
familiar with the inner workings of the FIB/neighbour kernel code.

[1] https://lore.kernel.org/netdev/55a04a8f-56f3-f73c-2aea-2195923f09d1@huawei.com/

Reported-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-02-21 11:44:30 +00:00
..
6lowpan net: don't include ndisc.h from ipv6.h 2022-02-04 14:15:11 -08:00
9p virtio,vdpa,qemu_fw_cfg: features, cleanups, fixes 2022-01-18 10:05:48 +02:00
802 net: 802: Use memset_startat() to clear struct fields 2021-11-19 11:23:23 +00:00
8021q vlan: move dev_put into vlan_dev_uninit 2022-02-09 13:33:39 +00:00
appletalk
atm proc: remove PDE_DATA() completely 2022-01-22 08:33:37 +02:00
ax25 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-10 17:29:56 -08:00
batman-adv ipv6: make mc_forwarding atomic 2022-02-05 15:20:34 +00:00
bluetooth bluetooth-next pull request for net-next: 2022-01-28 13:39:07 -08:00
bpf bpf: Make remote_port field in struct bpf_sk_lookup 16-bit wide 2022-02-09 11:40:45 -08:00
bpfilter
bridge bridge: switch br_net_exit to batch mode 2022-02-19 16:20:12 +00:00
caif caif: cleanup double word in comment 2022-02-07 12:06:54 +00:00
can Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-10 17:29:56 -08:00
ceph libceph: optionally use bounce buffer on recv path in crc mode 2022-02-02 18:50:36 +01:00
core net: core: Use csum_replace_by_diff() and csum_sub() instead of opencoding 2022-02-21 11:40:44 +00:00
dcb
dccp dccp: remove max48() 2022-01-27 13:53:27 +00:00
decnet Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-12-31 14:35:40 +00:00
dns_resolver
dsa net: dsa: remove pcs_poll 2022-02-19 16:41:50 +00:00
ethernet gro: remove rcu_read_lock/rcu_read_unlock from gro_complete handlers 2021-11-24 17:21:42 -08:00
ethtool ethtool: add header/data split indication 2022-01-28 14:43:47 +00:00
hsr net: hsr: fix suspicious RCU usage warning in hsr_node_get_first() 2022-02-19 16:39:45 +00:00
ieee802154 Merge tag 'ieee802154-for-davem-2022-02-10' of git://git.kernel.org/pub/scm/linux/kernel/git/sschmidt/wpan-next 2022-02-10 14:28:04 +00:00
ife
ipv4 ipv4: Invalidate neighbour for broadcast address upon address addition 2022-02-21 11:44:30 +00:00
ipv6 net: tcp: use kfree_skb_reason() for tcp_v{4,6}_do_rcv() 2022-02-20 13:55:31 +00:00
iucv net: Don't include filter.h from net/sock.h 2021-12-29 08:48:14 -08:00
kcm net: Don't include filter.h from net/sock.h 2021-12-29 08:48:14 -08:00
key
l2tp l2tp: add netns refcount tracker to l2tp_dfs_seq_data 2021-12-10 06:38:27 -08:00
l3mdev
lapb
llc sock: Use sock_owned_by_user_nocheck() instead of sk_lock.owned. 2021-12-10 19:43:00 -08:00
mac80211 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-17 11:44:20 -08:00
mac802154
mctp mctp: add address validity checking for packet receive 2022-02-18 21:24:29 -08:00
mpls net: mpls: Fix GCC 12 warning 2022-02-10 15:29:39 +00:00
mptcp mptcp: don't save tcp data_ready and write space callbacks 2022-02-16 20:52:06 -08:00
ncsi all: replace find_next{,_zero}_bit with find_first{,_zero}_bit where appropriate 2022-01-15 08:47:31 -08:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-17 11:44:20 -08:00
netlabel lsm: security_task_getsecid_subj() -> security_current_getsecid_subj() 2021-11-22 17:52:47 -05:00
netlink net: Don't include filter.h from net/sock.h 2021-12-29 08:48:14 -08:00
netrom netrom: fix api breakage in nr_setsockopt() 2022-01-07 14:11:05 +00:00
nfc Networking fixes for 5.17-rc1, including fixes from netfilter, bpf. 2022-01-20 10:57:05 +02:00
nsh
openvswitch net/sched: Enable tc skb ext allocation on chain miss only when needed 2022-02-05 10:12:53 +00:00
packet af_packet: fix data-race in packet_setsockopt / packet_setsockopt 2022-02-01 20:21:10 -08:00
phonet phonet/pep: refuse to enable an unbound pipe 2021-12-20 11:49:51 +00:00
psample
qrtr bus: mhi: core: Add an API for auto queueing buffers for DL channel 2021-12-17 17:17:14 +01:00
rds Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-12-16 16:13:19 -08:00
rfkill rfkill: allow to get the software rfkill state 2021-12-20 11:02:38 +01:00
rose net: Don't include filter.h from net/sock.h 2021-12-29 08:48:14 -08:00
rxrpc rxrpc: Adjust retransmission backoff 2022-01-22 02:03:24 +00:00
sched Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-17 11:44:20 -08:00
sctp Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-01-05 14:36:10 -08:00
smc net/smc: unlock on error paths in __smc_setsockopt() 2022-02-19 18:54:43 +00:00
strparser bpf: sockmap, strparser, and tls are reusing qdisc_skb_cb and colliding 2021-11-09 01:05:28 +01:00
sunrpc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-10 17:29:56 -08:00
switchdev net: switchdev: introduce switchdev_handle_port_obj_{add,del} for foreign interfaces 2022-02-16 11:21:04 +00:00
tipc Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-17 11:44:20 -08:00
tls tls: cap the output scatter list to something reasonable 2022-02-04 10:14:07 +00:00
unix Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2022-01-24 15:42:29 -08:00
vmw_vsock vsock: remove vsock from connected table when connect is interrupted by a signal 2022-02-17 08:56:02 -08:00
wireless Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2022-02-17 11:44:20 -08:00
x25 net: x25: drop harmless check of !more 2021-12-09 18:35:11 -08:00
xdp i40e: xsk: Move tmp desc array from driver to pool 2022-01-27 17:25:32 +01:00
xfrm xfrm: Don't accidentally set RTO_ONLINK in decode_session4() 2022-01-11 20:36:08 -08:00
compat.c
devres.c
Kconfig net: kunit: add a test for dev_addr_lists 2021-11-20 12:25:57 +00:00
Kconfig.debug net: add networking namespace refcount tracker 2021-12-10 06:38:26 -08:00
Makefile
socket.c net: fix documentation for kernel_getsockname 2022-02-14 14:01:19 +00:00
sysctl_net.c sections: move and rename core_kernel_data() to is_kernel_core_data() 2021-11-09 10:02:50 -08:00