android_kernel_xiaomi_sm8350/include
Ido Schimmel 73dd98ac19 ipv4: Invalidate neighbour for broadcast address upon address addition
[ Upstream commit 0c51e12e218f20b7d976158fdc18019627326f7a ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-15 14:18:33 +02:00
..
acpi ACPICA: actypes.h: Expand the ACPI_ACCESS_ definitions 2022-01-27 09:19:45 +01:00
asm-generic module/ftrace: handle patchable-function-entry 2022-02-23 11:59:56 +01:00
clocksource
crypto crypto: public_key: fix overflow during implicit conversion 2021-09-22 12:26:21 +02:00
drm drm: Return -ENOTTY for non-drm ioctls 2021-07-28 13:31:01 +02:00
dt-bindings
keys
kvm
linux ipv6: make mc_forwarding atomic 2022-04-15 14:18:32 +02:00
math-emu
media media: subdev: disallow ioctl for saa6588/davinci 2021-07-19 08:53:17 +02:00
misc
net ipv4: Invalidate neighbour for broadcast address upon address addition 2022-04-15 14:18:33 +02:00
pcmcia
ras
rdma RDMA/netlink: Add __maybe_unused to static inline in C file 2021-11-26 10:47:18 +01:00
scsi scsi: iscsi: Fix conn use after free during resets 2021-07-20 16:10:43 +02:00
soc
sound ALSA: hda: hdac_ext_stream: fix potential locking issues 2021-11-26 10:47:23 +01:00
target scsi: target: Fix ordered tag handling 2021-11-26 10:47:16 +01:00
trace f2fs: fix up f2fs_lookup tracepoints 2021-11-26 10:47:17 +01:00
uapi bpf: Make dst_port field in struct bpf_sock 16-bit wide 2022-04-15 14:18:32 +02:00
vdso
video
xen xen/gnttab: fix gnttab_end_foreign_access() without page specified 2022-03-11 11:22:39 +01:00