linux-stable.git/net/ipv6, branch v4.19.7

netfilter: ipv6: fix oops when defragmenting locally generated fragments

2018-11-27T15:13:01+00:00

[ Upstream commit 61792b677415b77c8db04991c22966bb8de7603e ]

Unlike ipv4 and normal ipv6 defrag, netfilter ipv6 defragmentation did
not save/restore skb->dst.

This causes oops when handling locally generated ipv6 fragments, as
output path needs a valid dst.

Reported-by: Maciej Żenczykowski 
Fixes: 84379c9afe01 ("netfilter: ipv6: nf_defrag: drop skb dst before queueing")
Signed-off-by: Florian Westphal 
Reviewed-by: Eric Dumazet 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

ipv6: Fix PMTU updates for UDP/raw sockets in presence of VRF

2018-11-23T07:17:02+00:00

[ Upstream commit 7ddacfa564870cdd97275fd87decb6174abc6380 ]

Preethi reported that PMTU discovery for UDP/raw applications is not
working in the presence of VRF when the socket is not bound to a device.
The problem is that ip6_sk_update_pmtu does not consider the L3 domain
of the skb device if the socket is not bound. Update the function to
set oif to the L3 master device if relevant.

Fixes: ca254490c8df ("net: Add VRF support to IPv6 stack")
Reported-by: Preethi Ramachandra 
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6: fix a dst leak when removing its exception

2018-11-23T07:17:02+00:00

[ Upstream commit 761f60261b4401aa368d71d431b4c218af0efcee ]

These is no need to hold dst before calling rt6_remove_exception_rt().
The call to dst_hold_safe() in ip6_link_failure() was for ip6_del_rt(),
which has been removed in Commit 93531c674315 ("net/ipv6: separate
handling of FIB entries from dst based routes"). Otherwise, it will
cause a dst leak.

This patch is to simply remove the dst_hold_safe() call before calling
rt6_remove_exception_rt() and also do the same in ip6_del_cached_rt().
It's safe, because the removal of the exception that holds its dst's
refcnt is protected by rt6_exception_lock.

Fixes: 93531c674315 ("net/ipv6: separate handling of FIB entries from dst based routes")
Fixes: 23fb93a4d3f1 ("net/ipv6: Cleanup exception and cache route handling")
Reported-by: Li Shuang 
Signed-off-by: Xin Long 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net/ipv6: Allow onlink routes to have a device mismatch if it is the default route

2018-11-04T13:50:52+00:00

[ Upstream commit 4ed591c8ab44e711e56b8e021ffaf4f407c045f5 ]

The intent of ip6_route_check_nh_onlink is to make sure the gateway
given for an onlink route is not actually on a connected route for
a different interface (e.g., 2001:db8:1::/64 is on dev eth1 and then
an onlink route has a via 2001:db8:1::1 dev eth2). If the gateway
lookup hits the default route then it most likely will be a different
interface than the onlink route which is ok.

Update ip6_route_check_nh_onlink to disregard the device mismatch
if the gateway lookup hits the default route. Turns out the existing
onlink tests are passing because there is no default route or it is
an unreachable default, so update the onlink tests to have a default
route other than unreachable.

Fixes: fc1e64e1092f6 ("net/ipv6: Add support for onlink flag")
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: udp: fix handling of CHECKSUM_COMPLETE packets

2018-11-04T13:50:51+00:00

[ Upstream commit db4f1be3ca9b0ef7330763d07bf4ace83ad6f913 ]

Current handling of CHECKSUM_COMPLETE packets by the UDP stack is
incorrect for any packet that has an incorrect checksum value.

udp4/6_csum_init() will both make a call to
__skb_checksum_validate_complete() to initialize/validate the csum
field when receiving a CHECKSUM_COMPLETE packet. When this packet
fails validation, skb->csum will be overwritten with the pseudoheader
checksum so the packet can be fully validated by software, but the
skb->ip_summed value will be left as CHECKSUM_COMPLETE so that way
the stack can later warn the user about their hardware spewing bad
checksums. Unfortunately, leaving the SKB in this state can cause
problems later on in the checksum calculation.

Since the the packet is still marked as CHECKSUM_COMPLETE,
udp_csum_pull_header() will SUBTRACT the checksum of the UDP header
from skb->csum instead of adding it, leaving us with a garbage value
in that field. Once we try to copy the packet to userspace in the
udp4/6_recvmsg(), we'll make a call to skb_copy_and_csum_datagram_msg()
to checksum the packet data and add it in the garbage skb->csum value
to perform our final validation check.

Since the value we're validating is not the proper checksum, it's possible
that the folded value could come out to 0, causing us not to drop the
packet. Instead, we believe that the packet was checksummed incorrectly
by hardware since skb->ip_summed is still CHECKSUM_COMPLETE, and we attempt
to warn the user with netdev_rx_csum_fault(skb->dev);

Unfortunately, since this is the UDP path, skb->dev has been overwritten
by skb->dev_scratch and is no longer a valid pointer, so we end up
reading invalid memory.

This patch addresses this problem in two ways:
	1) Do not use the dev pointer when calling netdev_rx_csum_fault()
	   from skb_copy_and_csum_datagram_msg(). Since this gets called
	   from the UDP path where skb->dev has been overwritten, we have
	   no way of knowing if the pointer is still valid. Also for the
	   sake of consistency with the other uses of
	   netdev_rx_csum_fault(), don't attempt to call it if the
	   packet was checksummed by software.

	2) Add better CHECKSUM_COMPLETE handling to udp4/6_csum_init().
	   If we receive a packet that's CHECKSUM_COMPLETE that fails
	   verification (i.e. skb->csum_valid == 0), check who performed
	   the calculation. It's possible that the checksum was done in
	   software by the network stack earlier (such as Netfilter's
	   CONNTRACK module), and if that says the checksum is bad,
	   we can drop the packet immediately instead of waiting until
	   we try and copy it to userspace. Otherwise, we need to
	   mark the SKB as CHECKSUM_NONE, since the skb->csum field
	   no longer contains the full packet checksum after the
	   call to __skb_checksum_validate_complete().

Fixes: e6afc8ace6dd ("udp: remove headers from UDP packets before queueing")
Fixes: c84d949057ca ("udp: copy skb->truesize in the first cache line")
Cc: Sam Kumar 
Cc: Eric Dumazet 
Signed-off-by: Sean Tranchetti 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipv6/ndisc: Preserve IPv6 control buffer if protocol error handlers are called

2018-11-04T13:50:51+00:00

[ Upstream commit ee1abcf689353f36d9322231b4320926096bdee0 ]

Commit a61bbcf28a8c ("[NET]: Store skb->timestamp as offset to a base
timestamp") introduces a neighbour control buffer and zeroes it out in
ndisc_rcv(), as ndisc_recv_ns() uses it.

Commit f2776ff04722 ("[IPV6]: Fix address/interface handling in UDP and
DCCP, according to the scoping architecture.") introduces the usage of the
IPv6 control buffer in protocol error handlers (e.g. inet6_iif() in
present-day __udp6_lib_err()).

Now, with commit b94f1c0904da ("ipv6: Use icmpv6_notify() to propagate
redirect, instead of rt6_redirect()."), we call protocol error handlers
from ndisc_redirect_rcv(), after the control buffer is already stolen and
some parts are already zeroed out. This implies that inet6_iif() on this
path will always return zero.

This gives unexpected results on UDP socket lookup in __udp6_lib_err(), as
we might actually need to match sockets for a given interface.

Instead of always claiming the control buffer in ndisc_rcv(), do that only
when needed.

Fixes: b94f1c0904da ("ipv6: Use icmpv6_notify() to propagate redirect, instead of rt6_redirect().")
Signed-off-by: Stefano Brivio 
Reviewed-by: Sabrina Dubroca 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net/ipv6: Fix index counter for unicast addresses in in6_dump_addrs

2018-10-20T22:43:14+00:00

The loop wants to skip previously dumped addresses, so loops until
current index >= saved index. If the message fills it wants to save
the index for the next address to dump - ie., the one that did not
fit in the current message.

Currently, it is incrementing the index counter before comparing to the
saved index, and then the saved index is off by 1 - it assumes the
current address is going to fit in the message.

Change the index handling to increment only after a succesful dump.

Fixes: 502a2ffd7376a ("ipv6: convert idev_list to list macros")
Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

ip6_tunnel: Fix encapsulation layout

2018-10-18T23:54:40+00:00

Commit 058214a4d1df ("ip6_tun: Add infrastructure for doing
encapsulation") added the ip6_tnl_encap() call in ip6_tnl_xmit(), before
the call to ipv6_push_frag_opts() to append the IPv6 Tunnel Encapsulation
Limit option (option 4, RFC 2473, par. 5.1) to the outer IPv6 header.

As long as the option didn't actually end up in generated packets, this
wasn't an issue. Then commit 89a23c8b528b ("ip6_tunnel: Fix missing tunnel
encapsulation limit option") fixed sending of this option, and the
resulting layout, e.g. for FoU, is:

.-------------------.------------.----------.-------------------.----- - -
| Outer IPv6 Header | UDP header | Option 4 | Inner IPv6 Header | Payload
'-------------------'------------'----------'-------------------'----- - -

Needless to say, FoU and GUE (at least) won't work over IPv6. The option
is appended by default, and I couldn't find a way to disable it with the
current iproute2.

Turn this into a more reasonable:

.-------------------.----------.------------.-------------------.----- - -
| Outer IPv6 Header | Option 4 | UDP header | Inner IPv6 Header | Payload
'-------------------'----------'------------'-------------------'----- - -

With this, and with 84dad55951b0 ("udp6: fix encap return code for
resubmitting"), FoU and GUE work again over IPv6.

Fixes: 058214a4d1df ("ip6_tun: Add infrastructure for doing encapsulation")
Signed-off-by: Stefano Brivio 
Signed-off-by: David S. Miller

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec

2018-10-18T16:55:08+00:00

Steffen Klassert says:

====================
pull request (net): ipsec 2018-10-18

1) Free the xfrm interface gro_cells when deleting the
   interface, otherwise we leak it. From Li RongQing.

2) net/core/flow.c does not exist anymore, so remove it
   from the MAINTAINERS file.

3) Fix a slab-out-of-bounds in _decode_session6.
   From Alexei Starovoitov.

4) Fix RCU protection when policies inserted into
   thei bydst lists. From Florian Westphal.

Please pull or let me know if there are problems.
====================

Signed-off-by: David S. Miller

udp6: fix encap return code for resubmitting

2018-10-18T05:26:53+00:00

The commit eb63f2964dbe ("udp6: add missing checks on edumux packet
processing") used the same return code convention of the ipv4 counterpart,
but ipv6 uses the opposite one: positive values means resubmit.

This change addresses the issue, using positive return value for
resubmitting. Also update the related comment, which was broken, too.

Fixes: eb63f2964dbe ("udp6: add missing checks on edumux packet processing")
Signed-off-by: Paolo Abeni 
Signed-off-by: David S. Miller