When TEE target mirrors traffic to another interface, sk_buff may
not have enough headroom to be processed correctly.
ip_finish_output2() detect this situation for ipv4 and allocates
new skb with enogh headroom. However ipv6 lacks this logic in
ip_finish_output2 and it leads to skb_under_panic:
skbuff: skb_under_panic: text:ffffffffc0866ad4 len:96 put:24
head:ffff97be85e31800 data:ffff97be85e317f8 tail:0x58 end:0xc0 dev:gre0
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:110!
invalid opcode: 0000 [#1] SMP PTI
CPU: 2 PID: 393 Comm: kworker/2:2 Tainted: G OE 5.13.0 #13
Hardware name: Virtuozzo KVM, BIOS 1.11.0-2.vz7.4 04/01/2014
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:skb_panic+0x48/0x4a
Call Trace:
skb_push.cold.111+0x10/0x10
ipgre_header+0x24/0xf0 [ip_gre]
neigh_connected_output+0xae/0xf0
ip6_finish_output2+0x1a8/0x5a0
ip6_output+0x5c/0x110
nf_dup_ipv6+0x158/0x1000 [nf_dup_ipv6]
tee_tg6+0x2e/0x40 [xt_TEE]
ip6t_do_table+0x294/0x470 [ip6_tables]
nf_hook_slow+0x44/0xc0
nf_hook.constprop.34+0x72/0xe0
ndisc_send_skb+0x20d/0x2e0
ndisc_send_ns+0xd1/0x210
addrconf_dad_work+0x3c8/0x540
process_one_work+0x1d1/0x370
worker_thread+0x30/0x390
kthread+0x116/0x130
ret_from_fork+0x22/0x30
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit e05a90ec9e ("net: reflect mark on tcp syn ack packets")
fixed IPv4 only.
This part is for the IPv6 side.
Fixes: e05a90ec9e ("net: reflect mark on tcp syn ack packets")
Signed-off-by: Alexander Ovechkin <ovov@yandex-team.ru>
Acked-by: Dmitry Yakunin <zeil@yandex-team.ru>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While TCP stack scales reasonably well, there is still one part that
can be used to DDOS it.
IPv6 Packet too big messages have to lookup/insert a new route,
and if abused by attackers, can easily put hosts under high stress,
with many cpus contending on a spinlock while one is stuck in fib6_run_gc()
ip6_protocol_deliver_rcu()
icmpv6_rcv()
icmpv6_notify()
tcp_v6_err()
tcp_v6_mtu_reduced()
inet6_csk_update_pmtu()
ip6_rt_update_pmtu()
__ip6_rt_update_pmtu()
ip6_rt_cache_alloc()
ip6_dst_alloc()
dst_alloc()
ip6_dst_gc()
fib6_run_gc()
spin_lock_bh() ...
Some of our servers have been hit by malicious ICMPv6 packets
trying to _increase_ the MTU/MSS of TCP flows.
We believe these ICMPv6 packets are a result of a bug in one ISP stack,
since they were blindly sent back for _every_ (small) packet sent to them.
These packets are for one TCP flow:
09:24:36.266491 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.266509 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.316688 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.316704 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
09:24:36.608151 IP6 Addr1 > Victim ICMP6, packet too big, mtu 1460, length 1240
TCP stack can filter some silly requests :
1) MTU below IPV6_MIN_MTU can be filtered early in tcp_v6_err()
2) tcp_v6_mtu_reduced() can drop requests trying to increase current MSS.
This tests happen before the IPv6 routing stack is entered, thus
removing the potential contention and route exhaustion.
Note that IPv6 stack was performing these checks, but too late
(ie : after the route has been added, and after the potential
garbage collect war)
v2: fix typo caught by Martin, thanks !
v3: exports tcp_mtu_to_mss(), caught by David, thanks !
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The goal of commit df789fe752 ("ipv6: Provide ipv6 version of
"disable_policy" sysctl") was to have the disable_policy from ipv4
available on ipv6.
However, it's not exactly the same mechanism. On IPv4, all packets coming
from an interface, which has disable_policy set, bypass the policy check.
For ipv6, this is done only for local packets, ie for packets destinated to
an address configured on the incoming interface.
Let's align ipv6 with ipv4 so that the 'disable_policy' sysctl has the same
effect for both protocols.
My first approach was to create a new kind of route cache entries, to be
able to set DST_NOPOLICY without modifying routes. This would have added a
lot of code. Because the local delivery path is already handled, I choose
to focus on the forwarding path to minimize code churn.
Fixes: df789fe752 ("ipv6: Provide ipv6 version of "disable_policy" sysctl")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
While tp->mtu_info is read while socket is owned, the write
sides happen from err handlers (tcp_v[46]_mtu_reduced)
which only own the socket spinlock.
Fixes: 563d34d057 ("tcp: dont drop MTU reduction indications")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 628a5c5618 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE") introduced
ip6_skb_dst_mtu with return value of signed int which is inconsistent
with actually returned values. Also 2 users of this function actually
assign its value to unsigned int variable and only __xfrm6_output
assigns result of this function to signed variable but actually uses
as unsigned in further comparisons and calls. Change this function
to return unsigned int value.
Fixes: 628a5c5618 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE")
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Trivial conflict in net/netfilter/nf_tables_api.c.
Duplicate fix in tools/testing/selftests/net/devlink_port_split.py
- take the net-next version.
skmsg, and L4 bpf - keep the bpf code but remove the flags
and err params.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch introduces a function wrapper to call the sk_error_report
callback. That will prepare to add additional handling whenever
sk_error_report is called, for example to trace socket errors.
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch builds off of commit 2b246b2569
and adds functionality to respond to ICMPV6 PROBE requests.
Add icmp_build_probe function to construct PROBE requests for both
ICMPV4 and ICMPV6.
Modify icmpv6_rcv to detect ICMPV6 PROBE messages and call the
icmpv6_echo_reply handler.
Modify icmpv6_echo_reply to build a PROBE response message based on the
queried interface.
This patch has been tested using a branch of the iputils git repo which can
be found here: https://github.com/Juniper-Clinic-2020/iputils/tree/probe-request
Signed-off-by: Andreas Roeseler <andreas.a.roeseler@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
/klassert/ipsec-next
Steffen Klassert says:
====================
pull request (net-next): ipsec-next 2021-06-28
1) Remove an unneeded error assignment in esp4_gro_receive().
From Yang Li.
2) Add a new byseq state hashtable to find acquire states faster.
From Sabrina Dubroca.
3) Remove some unnecessary variables in pfkey_create().
From zuoqilin.
4) Remove the unused description from xfrm_type struct.
From Florian Westphal.
5) Fix a spelling mistake in the comment of xfrm_state_ok().
From gushengxian.
6) Replace hdr_off indirections by a small helper function.
From Florian Westphal.
7) Remove xfrm4_output_finish and xfrm6_output_finish declarations,
they are not used anymore.From Antony Antony.
8) Remove xfrm replay indirections.
From Florian Westphal.
Please pull or let me know if there are problems.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Reset the mac_header pointer even when the tunnel transports only L3
data (in the ARPHRD_ETHER case, this is already done by eth_type_trans).
This prevents other parts of the stack from mistakenly accessing the
outer header after the packet has been decapsulated.
In practice, this allows to push an Ethernet header to ipip6, ip6ip6,
mplsip6 or ip6gre packets and redirect them to an Ethernet device:
$ tc filter add dev ip6tnl0 ingress matchall \
action vlan push_eth dst_mac 00:00:5e:00:53:01 \
src_mac 00:00:5e:00:53:00 \
action mirred egress redirect dev eth0
Without this patch, push_eth refuses to add an ethernet header because
the skb appears to already have a MAC header.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Even though sit transports L3 data (IPv6, IPv4 or MPLS) packets, it
needs to reset the mac_header pointer, so that other parts of the stack
don't mistakenly access the outer header after the packet has been
decapsulated. There are two rx handlers to modify: ipip6_rcv() for the
ip6ip mode and sit_tunnel_rcv() which is used to re-implement the ipip
and mplsip modes of ipip.ko.
This allows to push an Ethernet header to sit packets and redirect
them to an Ethernet device:
$ tc filter add dev sit0 ingress matchall \
action vlan push_eth dst_mac 00:00:5e:00:53:01 \
src_mac 00:00:5e:00:53:00 \
action mirred egress redirect dev eth0
Without this patch, push_eth refuses to add an ethernet header because
the skb appears to already have a MAC header.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
First problem is that optlen is fetched without checking
there is more than one byte to parse.
Fix this by taking care of IPV6_TLV_PAD1 before
fetching optlen (under appropriate sanity checks against len)
Second problem is that IPV6_TLV_PADN checks of zero
padding are performed before the check of remaining length.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Fixes: c1412fce7e ("net/ipv6/exthdrs.c: Strict PadN option checking")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Dave observed number of machines hitting OOM on the UDP send
path. The workload seems to be sending large UDP packets over
loopback. Since loopback has MTU of 64k kernel will try to
allocate an skb with up to 64k of head space. This has a good
chance of failing under memory pressure. What's worse if
the message length is <32k the allocation may trigger an
OOM killer.
This is entirely avoidable, we can use an skb with page frags.
af_unix solves a similar problem by limiting the head
length to SKB_MAX_ALLOC. This seems like a good and simple
approach. It means that UDP messages > 16kB will now
use fragments if underlying device supports SG, if extra
allocator pressure causes regressions in real workloads
we can switch to trying the large allocation first and
falling back.
v4: pre-calculate all the additions to alloclen so
we can be sure it won't go over order-2
Reported-by: Dave Jones <dsj@fb.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
I see no reason why max_dst_opts_cnt and max_hbh_opts_cnt
are fetched from the initial net namespace.
The other sysctls (max_dst_opts_len & max_hbh_opts_len)
are in fact already using the current ns.
Note: it is not clear why ipv6_destopt_rcv() use two ways to
get to the netns :
1) dev_net(dst->dev)
Originally used to increment IPSTATS_MIB_INHDRERRORS
2) dev_net(skb->dev)
Tom used this variant in his patch.
Maybe this calls to use ipv6_skb_net() instead ?
Fixes: 47d3d7ac65 ("ipv6: Implement limits on Hop-by-Hop and Destination options")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@quantonium.net>
Cc: Coco Li <lixiaoyan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Steffen Klassert says:
====================
pull request (net): ipsec 2021-06-23
1) Don't return a mtu smaller than 1280 on IPv6 pmtu discovery.
From Sabrina Dubroca
2) Fix seqcount rcu-read side in xfrm_policy_lookup_bytype
for the PREEMPT_RT case. From Varad Gautam.
3) Remove a repeated declaration of xfrm_parse_spi.
From Shaokun Zhang.
4) IPv4 beet mode can't handle fragments, but IPv6 does.
commit 68dc022d04 ("xfrm: BEET mode doesn't support
fragments for inner packets") handled IPv4 and IPv6
the same way. Relax the check for IPv6 because fragments
are possible here. From Xin Long.
5) Memory allocation failures are not reported for
XFRMA_ENCAP and XFRMA_COADDR in xfrm_state_construct.
Fix this by moving both cases in front of the function.
6) Fix a missing initialization in the xfrm offload fallback
fail case for bonding devices. From Ayush Sawal.
Please pull or let me know if there are problems.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 6c11fbf97e ("ip6_tunnel: add MPLS transmit support")
moved assiging inner_ipproto down from ipxip6_tnl_xmit() to
its callee ip6_tnl_xmit(). The latter is also used by GRE.
Since commit 3872035241 ("gre: Use inner_proto to obtain inner
header protocol") GRE had been depending on skb->inner_protocol
during segmentation. It sets it in gre_build_header() and reads
it in gre_gso_segment(). Changes to ip6_tnl_xmit() overwrite
the protocol, resulting in GSO skbs getting dropped.
Note that inner_protocol is a union with inner_ipproto,
GRE uses the former while the change switched it to the latter
(always setting it to just IPPROTO_GRE).
Restore the original location of skb_set_inner_ipproto(),
it is unclear why it was moved in the first place.
Fixes: 6c11fbf97e ("ip6_tunnel: add MPLS transmit support")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Tested-by: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Trivial conflicts in net/can/isotp.c and
tools/testing/selftests/net/mptcp/mptcp_connect.sh
scaled_ppm_to_ppb() was moved from drivers/ptp/ptp_clock.c
to include/linux/ptp_clock_kernel.h in -next so re-apply
the fix there.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
IETF RFC 8986 [1] includes the definition of SRv6 End.DT4, End.DT6, and
End.DT46 Behaviors.
The current SRv6 code in the Linux kernel only implements End.DT4 and
End.DT6 which can be used respectively to support IPv4-in-IPv6 and
IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a
single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic.
The proposed End.DT46 implementation is meant to support the decapsulation
of IPv4 and IPv6 traffic coming from a single SRv6 tunnel.
The implementation of the SRv6 End.DT46 Behavior in the Linux kernel
greatly simplifies the setup and operations of SRv6 VPNs.
The SRv6 End.DT46 Behavior leverages the infrastructure of SRv6 End.DT{4,6}
Behaviors implemented so far, because it makes use of a VRF device in
order to force the routing lookup into the associated routing table.
To make the End.DT46 work properly, it must be guaranteed that the routing
table used for routing lookup operations is bound to one and only one VRF
during the tunnel creation. Such constraint has to be enforced by enabling
the VRF strict_mode sysctl parameter, i.e.:
$ sysctl -wq net.vrf.strict_mode=1
Note that the same approach is used for the SRv6 End.DT4 Behavior and for
the End.DT6 Behavior in VRF mode.
The command used to instantiate an SRv6 End.DT46 Behavior is
straightforward, i.e.:
$ ip -6 route add 2001:db8::1 encap seg6local action End.DT46 vrftable 100 dev vrf100.
[1] https://www.rfc-editor.org/rfc/rfc8986.html#name-enddt46-decapsulation-and-s
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Performance and impact of SRv6 End.DT46 Behavior on the SRv6 Networking
=======================================================================
This patch aims to add the SRv6 End.DT46 Behavior with minimal impact on
the performance of SRv6 End.DT4 and End.DT6 Behaviors.
In order to verify this, we tested the performance of the newly introduced
SRv6 End.DT46 Behavior and compared it with the performance of SRv6
End.DT{4,6} Behaviors, considering both the patched kernel and the kernel
before applying the End.DT46 patch (referred to as vanilla kernel).
In details, the following decapsulation scenarios were considered:
1.a) IPv6 traffic in SRv6 End.DT46 Behavior on patched kernel;
1.b) IPv4 traffic in SRv6 End.DT46 Behavior on patched kernel;
2.a) SRv6 End.DT6 Behavior (VRF mode) on patched kernel;
2.b) SRv6 End.DT4 Behavior on patched kernel;
3.a) SRv6 End.DT6 Behavior (VRF mode) on vanilla kernel (without the
End.DT46 patch);
3.b) SRv6 End.DT4 Behavior on vanilla kernel (without the End.DT46 patch).
All tests were performed on a testbed deployed on the CloudLab [2]
facilities. We considered IPv{4,6} traffic handled by a single core (at 2.4
GHz on a Xeon(R) CPU E5-2630 v3) on kernel 5.13-rc1 using packets of size
~ 100 bytes.
Scenario (1.a): average 684.70 kpps; std. dev. 0.7 kpps;
Scenario (1.b): average 711.69 kpps; std. dev. 1.2 kpps;
Scenario (2.a): average 690.70 kpps; std. dev. 1.2 kpps;
Scenario (2.b): average 722.22 kpps; std. dev. 1.7 kpps;
Scenario (3.a): average 690.02 kpps; std. dev. 2.6 kpps;
Scenario (3.b): average 721.91 kpps; std. dev. 1.2 kpps;
Considering the results for the patched kernel (1.a, 1.b, 2.a, 2.b) we
observe that the performance degradation incurred in using End.DT46 rather
than End.DT6 and End.DT4 respectively for IPv6 and IPv4 traffic is minimal,
around 0.9% and 1.5%. Such very minimal performance degradation is the
price to be paid if one prefers to use a single tunnel capable of handling
both types of traffic (IPv4 and IPv6).
Comparing the results for End.DT4 and End.DT6 under the patched and the
vanilla kernel (2.a, 2.b, 3.a, 3.b) we observe that the introduction of the
End.DT46 patch has no impact on the performance of End.DT4 and End.DT6.
[2] https://www.cloudlab.us
Signed-off-by: Andrea Mayer <andrea.mayer@uniroma2.it>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann says:
====================
pull-request: bpf-next 2021-06-17
The following pull-request contains BPF updates for your *net-next* tree.
We've added 50 non-merge commits during the last 25 day(s) which contain
a total of 148 files changed, 4779 insertions(+), 1248 deletions(-).
The main changes are:
1) BPF infrastructure to migrate TCP child sockets from a listener to another
in the same reuseport group/map, from Kuniyuki Iwashima.
2) Add a provably sound, faster and more precise algorithm for tnum_mul() as
noted in https://arxiv.org/abs/2105.05398, from Harishankar Vishwanathan.
3) Streamline error reporting changes in libbpf as planned out in the
'libbpf: the road to v1.0' effort, from Andrii Nakryiko.
4) Add broadcast support to xdp_redirect_map(), from Hangbin Liu.
5) Extends bpf_map_lookup_and_delete_elem() functionality to 4 more map
types, that is, {LRU_,PERCPU_,LRU_PERCPU_,}HASH, from Denis Salopek.
6) Support new LLVM relocations in libbpf to make them more linker friendly,
also add a doc to describe the BPF backend relocations, from Yonghong Song.
7) Silence long standing KUBSAN complaints on register-based shifts in
interpreter, from Daniel Borkmann and Eric Biggers.
8) Add dummy PT_REGS macros in libbpf to fail BPF program compilation when
target arch cannot be determined, from Lorenz Bauer.
9) Extend AF_XDP to support large umems with 1M+ pages, from Magnus Karlsson.
10) Fix two minor libbpf tc BPF API issues, from Kumar Kartikeya Dwivedi.
11) Move libbpf BPF_SEQ_PRINTF/BPF_SNPRINTF macros that can be used by BPF
programs to bpf_helpers.h header, from Florent Revest.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch also changes the code to call reuseport_migrate_sock() and
inet_reqsk_clone(), but unlike the other cases, we do not call
inet_reqsk_clone() right after reuseport_migrate_sock().
Currently, in the receive path for TCP_NEW_SYN_RECV sockets, its listener
has three kinds of refcnt:
(A) for listener itself
(B) carried by reuqest_sock
(C) sock_hold() in tcp_v[46]_rcv()
While processing the req, (A) may disappear by close(listener). Also, (B)
can disappear by accept(listener) once we put the req into the accept
queue. So, we have to hold another refcnt (C) for the listener to prevent
use-after-free.
For socket migration, we call reuseport_migrate_sock() to select a listener
with (A) and to increment the new listener's refcnt in tcp_v[46]_rcv().
This refcnt corresponds to (C) and is cleaned up later in tcp_v[46]_rcv().
Thus we have to take another refcnt (B) for the newly cloned request_sock.
In inet_csk_complete_hashdance(), we hold the count (B), clone the req, and
try to put the new req into the accept queue. By migrating req after
winning the "own_req" race, we can avoid such a worst situation:
CPU 1 looks up req1
CPU 2 looks up req1, unhashes it, then CPU 1 loses the race
CPU 3 looks up req2, unhashes it, then CPU 2 loses the race
...
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210612123224.12525-8-kuniyu@amazon.co.jp
If link mtu is too big, mld_newpack() allocates high-order page.
But most mld packets don't need high-order page.
So, it might waste unnecessary pages.
To avoid this, it makes mld_newpack() try to allocate order-0 page.
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The variable err is being initialized with a value that is never read, the
assignment is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After previous patches all remaining users set the function pointer to
the same function: xfrm6_find_1stfragopt.
So remove this function pointer and call ip6_find_1stfragopt directly.
Reduces size of xfrm_type to 64 bytes on 64bit platforms.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Place the call into the xfrm core. After this all remaining users
set the hdr_offset function pointer to the same function which opens
the possiblity to remove the indirection.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
This helper is relatively small, just move this to the xfrm core
and call it directly.
Next patch does the same for the ROUTING type.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for net:
1) Fix a crash when stateful expression with its own gc callback
is used in a set definition.
2) Skip IPv6 packets from any link-local address in IPv6 fib expression.
Add a selftest for this scenario, from Florian Westphal.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Kaustubh reported and diagnosed a panic in udp_lib_lookup().
The root cause is udp_abort() racing with close(). Both
racing functions acquire the socket lock, but udp{v6}_destroy_sock()
release it before performing destructive actions.
We can't easily extend the socket lock scope to avoid the race,
instead use the SOCK_DEAD flag to prevent udp_abort from doing
any action when the critical race happens.
Diagnosed-and-tested-by: Kaustubh Pandey <kapandey@codeaurora.org>
Fixes: 5d77dca828 ("net: diag: support SOCK_DESTROY for UDP sockets")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The ip6tables rpfilter match has an extra check to skip packets with
"::" source address.
Extend this to ipv6 fib expression. Else ipv6 duplicate address detection
packets will fail rpf route check -- lookup returns -ENETUNREACH.
While at it, extend the prerouting check to also cover the ingress hook.
Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1543
Fixes: f6d0cbcf09 ("netfilter: nf_tables: add fib expression")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Its set but never read. Reduces size of xfrm_type to 64 bytes on 64bit.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
When 'nla_parse_nested_deprecated' failed, it's no need to
BUG() here, return -EINVAL is ok.
Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for net-next:
1) Support for SCTP chunks matching on nf_tables, from Phil Sutter.
2) Skip LDMXCSR, we don't need a valid MXCSR state. From Stefano Brivio.
3) CONFIG_RETPOLINE for nf_tables set lookups, from Florian Westphal.
4) A few Kconfig leading spaces removal, from Juerg Haefliger.
5) Remove spinlock from xt_limit, from Jason Baron.
6) Remove useless initialization in xt_CT, oneliner from Yang Li.
7) Tree-wide replacement of netlink_unicast() by nfnetlink_unicast().
8) Reduce footprint of several structures: xt_action_param,
nft_pktinfo and nf_hook_state, from Florian.
10) Add nft_thoff() and nft_sk() helpers and use them, also from Florian.
11) Fix documentation in nf_tables pipapo avx2, from Florian Westphal.
12) Fix clang-12 fmt string warnings, also from Florian.
====================
This is a complement to commit aa6dd211e4 ("inet: use bigger hash
table for IP ID generation"), but focusing on some specific aspects
of IPv6.
Contary to IPv4, IPv6 only uses packet IDs with fragments, and with a
minimum MTU of 1280, it's much less easy to force a remote peer to
produce many fragments to explore its ID sequence. In addition packet
IDs are 32-bit in IPv6, which further complicates their analysis. On
the other hand, it is often easier to choose among plenty of possible
source addresses and partially work around the bigger hash table the
commit above permits, which leaves IPv6 partially exposed to some
possibilities of remote analysis at the risk of weakening some
protocols like DNS if some IDs can be predicted with a good enough
probability.
Given the wide range of permitted IDs, the risk of collision is extremely
low so there's no need to rely on the positive increment algorithm that
is shared with the IPv4 code via ip_idents_reserve(). We have a fast
PRNG, so let's simply call prandom_u32() and be done with it.
Performance measurements at 10 Gbps couldn't show any difference with
the previous code, even when using a single core, because due to the
large fragments, we're limited to only ~930 kpps at 10 Gbps and the cost
of the random generation is completely offset by other operations and by
the network transfer time. In addition, this change removes the need to
update a shared entry in the idents table so it may even end up being
slightly faster on large scale systems where this matters.
The risk of at least one collision here is about 1/80 million among
10 IDs, 1/850k among 100 IDs, and still only 1/8.5k among 1000 IDs,
which remains very low compared to IPv4 where all IDs are reused
every 4 to 80ms on a 10 Gbps flow depending on packet sizes.
Reported-by: Amit Klein <aksecurity@gmail.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20210529110746.6796-1-w@1wt.eu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This allows to change storage placement later on without changing readers.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The fragment offset in ipv4/ipv6 is a 16bit field, so use
u16 instead of unsigned int.
On 64bit: 40 bytes to 32 bytes. By extension this also reduces
nft_pktinfo (56 to 48 byte).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Commit dbd1759e6a ("ipv6: on reassembly, record frag_max_size")
filled the frag_max_size field in IP6CB in the input path.
The field should also be filled in case of atomic fragments.
Fixes: dbd1759e6a ('ipv6: on reassembly, record frag_max_size')
Signed-off-by: Francesco Ruggeri <fruggeri@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In-kernel notifications are already sent when the multipath hash policy
itself changes, but not when the multipath hash fields change.
Add these notifications, so that interested listeners (e.g., switch ASIC
drivers) could perform the necessary configuration.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a new multipath hash policy where the packet fields used for hash
calculation are determined by user space via the
fib_multipath_hash_fields sysctl that was introduced in the previous
patch.
The current set of available packet fields includes both outer and inner
fields, which requires two invocations of the flow dissector. Avoid
unnecessary dissection of the outer or inner flows by skipping
dissection if none of the outer or inner fields are required.
In accordance with the existing policies, when an skb is not available,
packet fields are extracted from the provided flow key. In which case,
only outer fields are considered.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
A subsequent patch will add a new multipath hash policy where the packet
fields used for multipath hash calculation are determined by user space.
This patch adds a sysctl that allows user space to set these fields.
The packet fields are represented using a bitmask and are common between
IPv4 and IPv6 to allow user space to use the same numbering across both
protocols. For example, to hash based on standard 5-tuple:
# sysctl -w net.ipv6.fib_multipath_hash_fields=0x0037
net.ipv6.fib_multipath_hash_fields = 0x0037
To avoid introducing holes in 'struct netns_sysctl_ipv6', move the
'bindv6only' field after the multipath hash fields.
The kernel rejects unknown fields, for example:
# sysctl -w net.ipv6.fib_multipath_hash_fields=0x1000
sysctl: setting key "net.ipv6.fib_multipath_hash_fields": Invalid argument
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
A subsequent patch will add another multipath hash policy where the
multipath hash is calculated directly by the policy specific code and
not outside of the switch statement.
Prepare for this change by moving the multipath hash calculation inside
the switch statement.
No functional changes intended.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The 'out_timer' label was added in commit 63152fc0de ("[NETNS][IPV6]
ip6_fib - gc timer per namespace") when the timer was allocated on the
heap.
Commit 417f28bb34 ("netns: dont alloc ipv6 fib timer list") removed
the allocation, but kept the label name.
Rename it to a more suitable name.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
mld_newpack() doesn't allow to allocate high order page,
only order-0 allocation is allowed.
If headroom size is too large, a kernel panic could occur in skb_put().
Test commands:
ip netns del A
ip netns del B
ip netns add A
ip netns add B
ip link add veth0 type veth peer name veth1
ip link set veth0 netns A
ip link set veth1 netns B
ip netns exec A ip link set lo up
ip netns exec A ip link set veth0 up
ip netns exec A ip -6 a a 2001:db8:0::1/64 dev veth0
ip netns exec B ip link set lo up
ip netns exec B ip link set veth1 up
ip netns exec B ip -6 a a 2001:db8:0::2/64 dev veth1
for i in {1..99}
do
let A=$i-1
ip netns exec A ip link add ip6gre$i type ip6gre \
local 2001:db8:$A::1 remote 2001:db8:$A::2 encaplimit 100
ip netns exec A ip -6 a a 2001:db8:$i::1/64 dev ip6gre$i
ip netns exec A ip link set ip6gre$i up
ip netns exec B ip link add ip6gre$i type ip6gre \
local 2001:db8:$A::2 remote 2001:db8:$A::1 encaplimit 100
ip netns exec B ip -6 a a 2001:db8:$i::2/64 dev ip6gre$i
ip netns exec B ip link set ip6gre$i up
done
Splat looks like:
kernel BUG at net/core/skbuff.c:110!
invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
CPU: 0 PID: 7 Comm: kworker/0:1 Not tainted 5.12.0+ #891
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:skb_panic+0x15d/0x15f
Code: 92 fe 4c 8b 4c 24 10 53 8b 4d 70 45 89 e0 48 c7 c7 00 ae 79 83
41 57 41 56 41 55 48 8b 54 24 a6 26 f9 ff <0f> 0b 48 8b 6c 24 20 89
34 24 e8 4a 4e 92 fe 8b 34 24 48 c7 c1 20
RSP: 0018:ffff88810091f820 EFLAGS: 00010282
RAX: 0000000000000089 RBX: ffff8881086e9000 RCX: 0000000000000000
RDX: 0000000000000089 RSI: 0000000000000008 RDI: ffffed1020123efb
RBP: ffff888005f6eac0 R08: ffffed1022fc0031 R09: ffffed1022fc0031
R10: ffff888117e00187 R11: ffffed1022fc0030 R12: 0000000000000028
R13: ffff888008284eb0 R14: 0000000000000ed8 R15: 0000000000000ec0
FS: 0000000000000000(0000) GS:ffff888117c00000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8b801c5640 CR3: 0000000033c2c006 CR4: 00000000003706f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
? ip6_mc_hdr.isra.26.constprop.46+0x12a/0x600
? ip6_mc_hdr.isra.26.constprop.46+0x12a/0x600
skb_put.cold.104+0x22/0x22
ip6_mc_hdr.isra.26.constprop.46+0x12a/0x600
? rcu_read_lock_sched_held+0x91/0xc0
mld_newpack+0x398/0x8f0
? ip6_mc_hdr.isra.26.constprop.46+0x600/0x600
? lock_contended+0xc40/0xc40
add_grhead.isra.33+0x280/0x380
add_grec+0x5ca/0xff0
? mld_sendpack+0xf40/0xf40
? lock_downgrade+0x690/0x690
mld_send_initial_cr.part.34+0xb9/0x180
ipv6_mc_dad_complete+0x15d/0x1b0
addrconf_dad_completed+0x8d2/0xbb0
? lock_downgrade+0x690/0x690
? addrconf_rs_timer+0x660/0x660
? addrconf_dad_work+0x73c/0x10e0
addrconf_dad_work+0x73c/0x10e0
Allowing high order page allocation could fix this problem.
Fixes: 72e09ad107 ("ipv6: avoid high order allocations")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
