linux/net/dccp
Jakub Kicinski dcc32f4f18 ipv6: weaken the v4mapped source check
This reverts commit 6af1799aaf.

Commit 6af1799aaf ("ipv6: drop incoming packets having a v4mapped
source address") introduced an input check against v4mapped addresses.
Use of such addresses on the wire is indeed questionable and not
allowed on public Internet. As the commit pointed out

  https://tools.ietf.org/html/draft-itojun-v6ops-v4mapped-harmful-02

lists potential issues.

Unfortunately there are applications which use v4mapped addresses,
and breaking them is a clear regression. For example v4mapped
addresses (or any semi-valid addresses, really) may be used
for uni-direction event streams or packet export.

Since the issue which sparked the addition of the check was with
TCP and request_socks in particular push the check down to TCPv6
and DCCP. This restores the ability to receive UDPv6 packets with
v4mapped address as the source.

Keep using the IPSTATS_MIB_INHDRERRORS statistic to minimize the
user-visible changes.

Fixes: 6af1799aaf ("ipv6: drop incoming packets having a v4mapped source address")
Reported-by: Sunyi Shao <sunyishao@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-18 11:19:23 -07:00
..
ccids net: dccp: Fix most of the kerneldoc warnings 2020-10-30 12:08:54 -07:00
ackvec.c net: dccp: Fix most of the kerneldoc warnings 2020-10-30 12:08:54 -07:00
ackvec.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
ccid.c net: dccp: Add __printf() markup to fix -Wsuggest-attribute=format 2020-10-30 11:31:46 -07:00
ccid.h net: dccp: Replace zero-length array with flexible-array member 2020-02-28 12:08:37 -08:00
dccp.h net: pass a sockptr_t into ->setsockopt 2020-07-24 15:41:54 -07:00
diag.c inet_diag: Move the INET_DIAG_REQ_BYTECODE nlattr to cb->data 2020-02-27 18:50:19 -08:00
feat.c dccp: Return the correct errno code 2021-02-06 11:15:28 -08:00
feat.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
input.c net: dccp: Convert to use the preferred fallthrough macro 2020-08-22 12:38:34 -07:00
ipv4.c selinux/stable-5.11 PR 20201214 2020-12-16 11:01:04 -08:00
ipv6.c ipv6: weaken the v4mapped source check 2021-03-18 11:19:23 -07:00
ipv6.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
Kconfig dccp: Replace HTTP links with HTTPS ones 2020-07-13 11:54:07 -07:00
Makefile net: dccp: Remove dccpprobe module 2018-01-02 14:27:30 -05:00
minisocks.c dccp: Add missing annotation for dccp_child_process() 2020-02-24 13:26:49 -08:00
options.c net: dccp: Convert to use the preferred fallthrough macro 2020-08-22 12:38:34 -07:00
output.c net: dccp: Fix most of the kerneldoc warnings 2020-10-30 12:08:54 -07:00
proto.c net: dccp: Convert to use the preferred fallthrough macro 2020-08-22 12:38:34 -07:00
qpolicy.c net: dccp: Fix most of the kerneldoc warnings 2020-10-30 12:08:54 -07:00
sysctl.c proc/sysctl: add shared variables for range check 2019-07-18 17:08:07 -07:00
timer.c net: dccp: convert tasklets to use new tasklet_setup() API 2020-11-07 10:40:56 -08:00
trace.h net: dccp: Add DCCP sendmsg trace event 2018-01-02 14:27:30 -05:00