In subflow_check_req(), if subflow sport is mismatch, will put msk,
destroy token, and destruct req, then return -EPERM, which can be
done by subflow_req_destructor() via:

  tcp_conn_request()
    |--__reqsk_free()
      |--subflow_req_destructor()

So we should remove these redundant code, otherwise will call
tcp_v4_reqsk_destructor() twice, and may double free
inet_rsk(req)->ireq_opt.

Fixes: 5bc56388

 ("mptcp: add port number check for MP_JOIN")
Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

I did stress test with wrk[1] and webfsd[2] with the assistance of
mptcp-tools[3]:

  Server side:
      ./use_mptcp.sh webfsd -4 -R /tmp/ -p 8099
  Client side:
      ./use_mptcp.sh wrk -c 200 -d 30 -t 4 http://192.168.174.129:8099/

and got the following warning message:

[   55.552626] TCP: request_sock_subflow: Possible SYN flooding on port 8099. Sending cookies.  Check SNMP counters.
[   55.553024] ------------[ cut here ]------------
[   55.553027] WARNING: CPU: 0 PID: 10 at net/core/flow_dissector.c:984 __skb_flow_dissect+0x280/0x1650
...
[   55.553117] CPU: 0 PID: 10 Comm: ksoftirqd/0 Not tainted 5.12.0+ #18
[   55.553121] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 02/27/2020
[   55.553124] RIP: 0010:__skb_flow_dissect+0x280/0x1650
...
[   55.553133] RSP: 0018:ffffb79580087770 EFLAGS: 00010246
[   55.553137] RAX: 0000000000000000 RBX: ffffffff8ddb58e0 RCX: ffffb79580087888
[   55.553139] RDX: ffffffff8ddb58e0 RSI: ffff8f7e4652b600 RDI: 0000000000000000
[   55.553141] RBP: ffffb79580087858 R08: 0000000000000000 R09: 0000000000000008
[   55.553143] R10: 000000008c622965 R11: 00000000d3313a5b R12: ffff8f7e4652b600
[   55.553146] R13: ffff8f7e465c9062 R14: 0000000000000000 R15: ffffb79580087888
[   55.553149] FS:  0000000000000000(0000) GS:ffff8f7f75e00000(0000) knlGS:0000000000000000
[   55.553152] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   55.553154] CR2: 00007f73d1d19000 CR3: 0000000135e10004 CR4: 00000000003706f0
[   55.553160] Call Trace:
[   55.553166]  ? __sha256_final+0x67/0xd0
[   55.553173]  ? sha256+0x7e/0xa0
[   55.553177]  __skb_get_hash+0x57/0x210
[   55.553182]  subflow_init_req_cookie_join_save+0xac/0xc0
[   55.553189]  subflow_check_req+0x474/0x550
[   55.553195]  ? ip_route_output_key_hash+0x67/0x90
[   55.553200]  ? xfrm_lookup_route+0x1d/0xa0
[   55.553207]  subflow_v4_route_req+0x8e/0xd0
[   55.553212]  tcp_conn_request+0x31e/0xab0
[   55.553218]  ? selinux_socket_sock_rcv_skb+0x116/0x210
[   55.553224]  ? tcp_rcv_state_process+0x179/0x6d0
[   55.553229]  tcp_rcv_state_process+0x179/0x6d0
[   55.553235]  tcp_v4_do_rcv+0xaf/0x220
[   55.553239]  tcp_v4_rcv+0xce4/0xd80
[   55.553243]  ? ip_route_input_rcu+0x246/0x260
[   55.553248]  ip_protocol_deliver_rcu+0x35/0x1b0
[   55.553253]  ip_local_deliver_finish+0x44/0x50
[   55.553258]  ip_local_deliver+0x6c/0x110
[   55.553262]  ? ip_rcv_finish_core.isra.19+0x5a/0x400
[   55.553267]  ip_rcv+0xd1/0xe0
...

After debugging, I found in __skb_flow_dissect(), skb->dev and skb->sk
are both NULL, then net is NULL, and trigger WARN_ON_ONCE(!net),
actually net is always NULL in this code path, as skb->dev is set to
NULL in tcp_v4_rcv(), and skb->sk is never set.

Code snippet in __skb_flow_dissect() that trigger warning:
  975         if (skb) {
  976                 if (!net) {
  977                         if (skb->dev)
  978                                 net = dev_net(skb->dev);
  979                         else if (skb->sk)
  980                                 net = sock_net(skb->sk);
  981                 }
  982         }
  983
  984         WARN_ON_ONCE(!net);

So, using seq and transport header derived hash.

[1] https://github.com/wg/wrk
[2] https://github.com/ourway/webfsd
[3] https://github.com/pabeni/mptcp-tools

Fixes: 9466a1cc

 ("mptcp: enable JOIN requests even if cookies are in use")
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
pull-request: bpf 2021-07-09

The following pull-request contains BPF updates for your *net* tree.

We've added 9 non-merge commits during the last 9 day(s) which contain
a total of 13 files changed, 118 insertions(+), 62 deletions(-).

The main changes are:

1) Fix runqslower task->state access from BPF, from SanjayKumar Jeyakumar.

2) Fix subprog poke descriptor tracking use-after-free, from John Fastabend.

3) Fix sparse complaint from prior devmap RCU conversion, from Toke Høiland-Jørgensen.

4) Fix missing va_end in bpftool JIT json dump's error path, from Gu Shengxian.

5) Fix tools/bpf install target from missing runqslower install, from Wei Li.

6) Fix xdpsock BPF sample to unload program on shared umem option, from Wang Hai.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

skb_tunnel_info() returns pointer of lwtstate->data as ip_tunnel_info
type without validation. lwtstate->data can have various types such as
mpls_iptunnel_encap, etc and these are not compatible.
So skb_tunnel_info() should validate before returning that pointer.

Splat looks like:
BUG: KASAN: slab-out-of-bounds in vxlan_get_route+0x418/0x4b0 [vxlan]
Read of size 2 at addr ffff888106ec2698 by task ping/811

CPU: 1 PID: 811 Comm: ping Not tainted 5.13.0+ #1195
Call Trace:
 dump_stack_lvl+0x56/0x7b
 print_address_description.constprop.8.cold.13+0x13/0x2ee
 ? vxlan_get_route+0x418/0x4b0 [vxlan]
 ? vxlan_get_route+0x418/0x4b0 [vxlan]
 kasan_report.cold.14+0x83/0xdf
 ? vxlan_get_route+0x418/0x4b0 [vxlan]
 vxlan_get_route+0x418/0x4b0 [vxlan]
 [ ... ]
 vxlan_xmit_one+0x148b/0x32b0 [vxlan]
 [ ... ]
 vxlan_xmit+0x25c5/0x4780 [vxlan]
 [ ... ]
 dev_hard_start_xmit+0x1ae/0x6e0
 __dev_queue_xmit+0x1f39/0x31a0
 [ ... ]
 neigh_xmit+0x2f9/0x940
 mpls_xmit+0x911/0x1600 [mpls_iptunnel]
 lwtunnel_xmit+0x18f/0x450
 ip_finish_output2+0x867/0x2040
 [ ... ]

Fixes: 61adedf3

 ("route: move lwtunnel state to dst_entry")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 28e104d0 ("net: ip_tunnel: fix mtu calculation") removed
dev->hard_header_len subtraction when calculate MTU for tunnel devices
as there is an overhead for device that has header_ops.

But there are ETHER tunnel devices, like gre_tap or erspan, which don't
have header_ops but set dev->hard_header_len during setup. This makes
pkts greater than (MTU - ETH_HLEN) could not be xmited. Fix it by
subtracting the ETHER tunnel devices' dev->hard_header_len for MTU
calculation.

Fixes: 28e104d0

 ("net: ip_tunnel: fix mtu calculation")
Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Some socket buffers allocated in the fclone cache (in __alloc_skb) can
end-up in the following path[1]:

napi_skb_finish
  __kfree_skb_defer
    napi_skb_cache_put

The issue is napi_skb_cache_put is not fclone friendly and will put
those skbuff in the skb cache to be reused later, although this cache
only expects skbuff allocated from skbuff_head_cache. When this happens
the skbuff is eventually freed using the wrong origin cache, and we can
see traces similar to:

[ 1223.947534] cache_from_obj: Wrong slab cache. skbuff_head_cache but object is from skbuff_fclone_cache
[ 1223.948895] WARNING: CPU: 3 PID: 0 at mm/slab.h:442 kmem_cache_free+0x251/0x3e0
[ 1223.950211] Modules linked in:
[ 1223.950680] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.13.0+ #474
[ 1223.951587] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-3.fc34 04/01/2014
[ 1223.953060] RIP: 0010:kmem_cache_free+0x251/0x3e0

Leading sometimes to other memory related issues.

Fix this by using __kfree_skb for fclone skbuff, similar to what is done
the other place __kfree_skb_defer is called.

[1] At least in setups using veth pairs and tunnels. Building a kernel
    with KASAN we can for example see packets allocated in
    sk_stream_alloc_skb hit the above path and later the issue arises
    when the skbuff is reused.

Fixes: 9243adfc

 ("skbuff: queue NAPI_MERGED_FREE skbs into NAPI cache instead of freeing")
Cc: Alexander Lobakin <alobakin@pm.me>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

sk_wmem_schedule makes sure that sk_forward_alloc has enough
bytes for charging that is going to be done by sk_mem_charge.

In the transmit zerocopy path, there is sk_mem_charge but there was
no call to sk_wmem_schedule. This change adds that call.

Without this call to sk_wmem_schedule, sk_forward_alloc can go
negetive which is a bug because sk_forward_alloc is a per-socket
space that has been forward charged so this can't be negative.

Fixes: f214f915

 ("tcp: enable MSG_ZEROCOPY")
Signed-off-by: Talal Ahmad <talalahmad@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Wei Wang <weiwan@google.com>
Reviewed-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

commit e05a90ec ("net: reflect mark on tcp syn ack packets")
fixed IPv4 only.

This part is for the IPv6 side.

Fixes: e05a90ec

 ("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>

priv is netdev private data and it cannot be
used after free_netdev() call. Using priv after free_netdev()
can cause UAF bug. Fix it by moving free_netdev() at the end of the
function.

Fixes: 1e0a8b13

 ("tlan: cancel work at remove path")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

adpt is netdev private data and it cannot be
used after free_netdev() call. Using adpt after free_netdev()
can cause UAF bug. Fix it by moving free_netdev() at the end of the
function.

Fixes: 54e19bc7

 ("net: qcom/emac: do not use devm on internal phy pdev")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In case of netdev registration failure the code path will
jump to init_fail label:

init_fail:
	netdev_err(ndev, "init failed\n");
	moxart_mac_free_memory(ndev);
irq_map_fail:
	free_netdev(ndev);
	return ret;

So, there is no need to call free_netdev() before jumping
to error handling path, since it can cause UAF or double-free
bug.

Fixes: 6c821bd9

 ("net: Add MOXA ART SoCs ethernet driver")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This adds some extra noise to the tailcall_bpf2bpf4 tests that will cause
verify to patch insns. This then moves around subprog start/end insn
index and poke descriptor insn index to ensure that verify and JIT will
continue to track these correctly.

If done correctly verifier should pass this program same as before and
JIT should emit tail call logic.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210707223848.14580-3-john.fastabend@gmail.com

Subprograms are calling map_poke_track(), but on program release there is no
hook to call map_poke_untrack(). However, on program release, the aux memory
(and poke descriptor table) is freed even though we still have a reference to
it in the element list of the map aux data. When we run map_poke_run(), we then
end up accessing free'd memory, triggering KASAN in prog_array_map_poke_run():

  [...]
  [  402.824689] BUG: KASAN: use-after-free in prog_array_map_poke_run+0xc2/0x34e
  [  402.824698] Read of size 4 at addr ffff8881905a7940 by task hubble-fgs/4337
  [  402.824705] CPU: 1 PID: 4337 Comm: hubble-fgs Tainted: G          I       5.12.0+ #399
  [  402.824715] Call Trace:
  [  402.824719]  dump_stack+0x93/0xc2
  [  402.824727]  print_address_description.constprop.0+0x1a/0x140
  [  402.824736]  ? prog_array_map_poke_run+0xc2/0x34e
  [  402.824740]  ? prog_array_map_poke_run+0xc2/0x34e
  [  402.824744]  kasan_report.cold+0x7c/0xd8
  [  402.824752]  ? prog_array_map_poke_run+0xc2/0x34e
  [  402.824757]  prog_array_map_poke_run+0xc2/0x34e
  [  402.824765]  bpf_fd_array_map_update_elem+0x124/0x1a0
  [...]

The elements concerned are walked as follows:

    for (i = 0; i < elem->aux->size_poke_tab; i++) {
           poke = &elem->aux->poke_tab[i];
    [...]

The access to size_poke_tab is a 4 byte read, verified by checking offsets
in the KASAN dump:

  [  402.825004] The buggy address belongs to the object at ffff8881905a7800
                 which belongs to the cache kmalloc-1k of size 1024
  [  402.825008] The buggy address is located 320 bytes inside of
                 1024-byte region [ffff8881905a7800, ffff8881905a7c00)

The pahole output of bpf_prog_aux:

  struct bpf_prog_aux {
    [...]
    /* --- cacheline 5 boundary (320 bytes) --- */
    u32                        size_poke_tab;        /*   320     4 */
    [...]

In general, subprograms do not necessarily manage their own data structures.
For example, BTF func_info and linfo are just pointers to the main program
structure. This allows reference counting and cleanup to be done on the latter
which simplifies their management a bit. The aux->poke_tab struct, however,
did not follow this logic. The initial proposed fix for this use-after-free
bug further embedded poke data tracking into the subprogram with proper
reference counting. However, Daniel and Alexei questioned why we were treating
these objects special; I agree, its unnecessary. The fix here removes the per
subprogram poke table allocation and map tracking and instead simply points
the aux->poke_tab pointer at the main programs poke table. This way, map
tracking is simplified to the main program and we do not need to manage them
per subprogram.

This also means, bpf_prog_free_deferred(), which unwinds the program reference
counting and kfrees objects, needs to ensure that we don't try to double free
the poke_tab when free'ing the subprog structures. This is easily solved by
NULL'ing the poke_tab pointer. The second detail is to ensure that per
subprogram JIT logic only does fixups on poke_tab[] entries it owns. To do
this, we add a pointer in the poke structure to point at the subprogram value
so JITs can easily check while walking the poke_tab structure if the current
entry belongs to the current program. The aux pointer is stable and therefore
suitable for such comparison. On the jit_subprogs() error path, we omit
cleaning up the poke->aux field because these are only ever referenced from
the JIT side, but on error we will never make it to the JIT, so its fine to
leave them dangling. Removing these pointers would complicate the error path
for no reason. However, we do need to untrack all poke descriptors from the
main program as otherwise they could race with the freeing of JIT memory from
the subprograms. Lastly, a748c697 ("bpf: propagate poke descriptors to
subprograms") had an off-by-one on the subprogram instruction index range
check as it was testing 'insn_idx >= subprog_start && insn_idx <= subprog_end'.
However, subprog_end is the next subprogram's start instruction.

Fixes: a748c697

 ("bpf: propagate poke descriptors to subprograms")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Co-developed-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210707223848.14580-2-john.fastabend@gmail.com

Make sure that we disable each of the TX and RX queues in the TDMA and
RDMA control registers. This is a correctness change to be symmetrical
with the code that enables the TX and RX queues.

Tested-by: Maxime Ripard <maxime@cerno.tech>
Fixes: 1c1008c7

 ("net: bcmgenet: add main driver file")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ivan Mikhaylov says:

====================
net/ncsi: Add NCSI Intel OEM command to keep PHY link up

Add NCSI Intel OEM command to keep PHY link up and prevents any channel
resets during the host load on i210. Also includes dummy response handler for
Intel manufacturer id.

Changes from v1:
 1. sparse fixes about casts
 2. put it after ncsi_dev_state_probe_cis instead of
    ncsi_dev_state_probe_channel because sometimes channel is not ready
    after it
 3. inl -> intel
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Add the dummy response handler for Intel boards to prevent incorrect
handling of OEM commands.

Signed-off-by: Ivan Mikhaylov <i.mikhaylov@yadro.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This allows to keep PHY link up and prevents any channel resets during
the host load.

It is KEEP_PHY_LINK_UP option(Veto bit) in i210 datasheet which
block PHY reset and power state changes.

Signed-off-by: Ivan Mikhaylov <i.mikhaylov@yadro.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sparse reports:
net/ncsi/ncsi-rsp.c:406:24: warning: cast to restricted __be32
net/ncsi/ncsi-manage.c:732:33: warning: cast to restricted __be32
net/ncsi/ncsi-manage.c:756:25: warning: cast to restricted __be32
net/ncsi/ncsi-manage.c:779:25: warning: cast to restricted __be32

Signed-off-by: Ivan Mikhaylov <i.mikhaylov@yadro.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

PHY_SPARX5_SERDES depends on OF so SPARX5_SWITCH should also depend
on OF since 'select' does not follow any dependencies.

WARNING: unmet direct dependencies detected for PHY_SPARX5_SERDES
  Depends on [n]: (ARCH_SPARX5 || COMPILE_TEST [=n]) && OF [=n] && HAS_IOMEM [=y]
  Selected by [y]:
  - SPARX5_SWITCH [=y] && NETDEVICES [=y] && ETHERNET [=y] && NET_VENDOR_MICROCHIP [=y] && NET_SWITCHDEV [=y] && HAS_IOMEM [=y]

Fixes: 3cfa11ba

 ("net: sparx5: add the basic sparx5 driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Lars Povlsen <lars.povlsen@microchip.com>
Cc: Steen Hegelund <Steen.Hegelund@microchip.com>
Cc: UNGLinuxDriver@microchip.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

IRQs are requested during driver's ndo_open() and then later
freed up in disable_interrupts() during driver unload.
A race exists where driver can set the CXGB4_FULL_INIT_DONE
flag in ndo_open() after the disable_interrupts() in driver
unload path checks it, and hence misses calling free_irq().

Fix by unregistering netdevice first and sync with driver's
ndo_open(). This ensures disable_interrupts() checks the flag
correctly and frees up the IRQs properly.

Fixes: b37987e8

 ("cxgb4: Disable interrupts and napi before unregistering netdev")
Signed-off-by: Shahjada Abul Husain <shahjada@chelsio.com>
Signed-off-by: Raju Rangoju <rajur@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When reboot system, no power cycles, firmware is already downloaded,
return -EIO will break driver as error:
mt7921e: probe of 0000:03:00.0 failed with error -5

Skip firmware download and continue to probe.

Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Fixes: 1c099ab4

 ("mt76: mt7921: add MCU support")
Signed-off-by: David S. Miller <davem@davemloft.net>

Since Mikrotik 10/25G NIC MDIO op emulation is not 100% reliable,
on rare occasions it can happen that some physical functions of
the NIC do not get initialized due to timeouted early MDIO op.

This changes the atl1c probe on Mikrotik 10/25G NIC not to
depend on MDIO op emulation.

Signed-off-by: Gatis Peisenieks <gatis@mikrotik.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

An earlier commit set the pps_lookup cookie, but the line
was somehow added to the wrong code block.  Correct this.

Fixes: 8602e40f

 ("ptp: Set lookup cookie when creating a PTP PPS source.")
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Dario Binacchi <dariobin@libero.it>
Acked-by: Richard Cochran <richardcochran@gmail.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: 1da177e4

 ("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>

We will fail to build with CONFIG_SKB_EXTENSIONS disabled after
8550ff8d ("skbuff: Release nfct refcount on napi stolen or re-used
skbs") since there is an unconditionally use of skb_ext_find() without
an appropriate stub. Simply build the code conditionally and properly
guard against both COFNIG_SKB_EXTENSIONS as well as
CONFIG_NET_TC_SKB_EXT being disabled.

Fixes: Fixes: 8550ff8d

 ("skbuff: Release nfct refcount on napi stolen or re-used skbs")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixed indentation by removing extra spaces.

Signed-off-by: Roy, UjjaL <royujjal@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

If copy_from_sockptr() then we need to unlock before returning.

Fixes: d463126e

 ("net: sock: extend SO_TIMESTAMPING for PHC binding")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

make[2]: *** No rule to make target 'install'.  Stop.
make[1]: *** [Makefile:122: runqslower_install] Error 2
make: *** [Makefile:116: bpf_install] Error 2

There is no rule for target 'install' in tools/bpf/runqslower/Makefile,
and there is no need to install it, so just remove 'runqslower_install'.

Fixes: 9c01546d

 ("tools/bpf: Add runqslower tool to tools/bpf")
Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210628030409.3459095-1-liwei391@huawei.com

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Do not refresh timeout in SYN_SENT for syn retransmissions.
   Add selftest for unreplied TCP connection, from Florian Westphal.

2) Fix null dereference from error path with hardware offload
   in nftables.

3) Remove useless nf_ct_gre_keymap_flush() from netns exit path,
   from Vasily Averin.

4) Missing rcu read-lock side in ctnetlink helper info dump,
   also from Vasily.

5) Do not mark RST in the reply direction coming after SYN packet
   for an out-of-sync entry, from Ali Abdallah and Florian Westphal.

6) Add tcp_ignore_invalid_rst sysctl to allow to disable out of
   segment RSTs, from Ali.

7) KCSAN fix for nf_conntrack_all_lock(), from Manfred Spraul.

8) Honor NFTA_LAST_SET in nft_last.

9) Fix incorrect arithmetics when restore last_jiffies in nft_last.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

After redirecting, it's already a new path. So the old PMTU info should
be cleared. The IPv6 test "mtu exception plus redirect" should only
has redirect info without old PMTU.

The IPv4 test can not be changed because of legacy.

Fixes: ec810535

 ("selftests: Add redirect tests")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

If the kernel doesn't enable option CONFIG_IPV6_SUBTREES, the RTA_SRC
info will not be exported to userspace in rt6_fill_node(). And ip cmd will
not print "from ::" to the route output. So remove this check.

Fixes: ec810535

 ("selftests: Add redirect tests")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The "plat->phy_interface" variable is an enum and in this context GCC
will treat it as an unsigned int so the error handling is never
triggered.

Fixes: b9f0b2f6

 ("net: stmmac: platform: fix probe for ACPI devices")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

plat->phy_interface is unsigned integer, so the condition
can't be less than zero and the warning will never printed.

Fixes: 30bba69d

 ("stmmac: pci: Add dwmac support for Loongson")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit 2f064a59 ("sched: Change task_struct::state") renamed task->state
to task->__state in task_struct. Fix runqslower to use the new name of the
field.

Fixes: 2f064a59

 ("sched: Change task_struct::state")
Signed-off-by: SanjayKumar Jeyakumar <vjsanjay@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210707052914.21473-1-vjsanjay@gmail.com

nf_conntrack_netlink.h does not exist, refer to nfnetlink_conntrack.h instead.

Signed-off-by: Duncan Roe <duncan_roe@optusnet.com.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

The update to streamline libbpf error reporting intended to change all
functions to return the errno as a negative return value if
LIBBPF_STRICT_DIRECT_ERRS is set. However, if the flag is *not* set, the
return value changes for the two functions that were already returning a
negative errno unconditionally: bpf_link__unpin() and perf_buffer__poll().

This is a user-visible API change that breaks applications; so let's revert
these two functions back to unconditionally returning a negative errno
value.

Fixes: e9fc3ce9

 ("libbpf: Streamline error reporting for high-level APIs")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210706122355.236082-1-toke@redhat.com

The goal of commit df789fe7 ("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: df789fe7

 ("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>

Currently when the call to otx2_mbox_alloc_msg_cgx_mac_addr_update fails
the error return variable rc is being assigned -ENOMEM and does not
return early. rc is then re-assigned and the error case is not handled
correctly. Fix this by returning -ENOMEM rather than assigning rc.

Addresses-Coverity: ("Unused value")
Fixes: 79d2be38

 ("octeontx2-pf: offload DMAC filters to CGX/RPM block")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Taehee Yoo says:

====================
net: fix bonding ipsec offload problems

This series fixes some problems related to bonding ipsec offload.

The 1, 5, and 8th patches are to add a missing rcu_read_lock().
The 2nd patch is to add null check code to bond_ipsec_add_sa.
When bonding interface doesn't have an active real interface, the
bond->curr_active_slave pointer is null.
But bond_ipsec_add_sa() uses that pointer without null check.
So that it results in null-ptr-deref.
The 3 and 4th patches are to replace xs->xso.dev with xs->xso.real_dev.
The 6th patch is to disallow to set ipsec offload if a real interface
type is bonding.
The 7th patch is to add struct bond_ipsec to manage SA.
If bond mode is changed, or active real interface is changed, SA should
be removed from old current active real interface then it should be added
to new active real interface.
But it can't, because it doesn't manage SA.
The 9th patch is to fix incorrect return value of bond_ipsec_offload_ok().

v1 -> v2:
 - Add 9th patch.
 - Do not print warning when there is no SA in bond_ipsec_add_sa_all().
 - Add comment for ipsec_lock.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

bond_ipsec_offload_ok() is called to check whether the interface supports
ipsec offload or not.
bonding interface support ipsec offload only in active-backup mode.
So, if a bond interface is not in active-backup mode, it should return
false but it returns true.

Fixes: a3b658cf

 ("bonding: allow xfrm offload setup post-module-load")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>