Fast Open key could be stored in different endian based on the CPU.
Previously hosts in different endianness in a server farm using
the same key config (sysctl value) would produce different cookies.
This patch fixes it by always storing it as little endian to keep
same API for LE hosts.
Reported-by: NDaniele Iamartino <danielei@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Merge tag 'mac80211-for-davem-2018-06-29' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

Johannes Berg says:

====================
Just three fixes:
 * fix HT operation in mesh mode
 * disable preemption in control frame TX
 * check nla_parse_nested() return values
   where missing (two places)
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently the kernel accounts the memory for network traffic through
mem_cgroup_[un]charge_skmem() interface. However the memory accounted
only includes the truesize of sk_buff which does not include the size of
sock objects. In our production environment, with opt-out kmem
accounting, the sock kmem caches (TCP[v6], UDP[v6], RAW[v6], UNIX) are
among the top most charged kmem caches and consume a significant amount
of memory which can not be left as system overhead. So, this patch
converts the kmem caches of all sock objects to SLAB_ACCOUNT.
Signed-off-by: NShakeel Butt <shakeelb@google.com>
Suggested-by: NEric Dumazet <edumazet@google.com>
Reviewed-by: NKirill Tkhai <ktkhai@virtuozzo.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

At the very least we should check the return value if
nla_parse_nested() is called with a non-NULL policy.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Commit 9757235f, "nl80211: correct checks for
NL80211_MESHCONF_HT_OPMODE value") relaxed the range for the HT
operation field in meshconf, while also adding checks requiring
the non-greenfield and non-ht-sta bits to be set in certain
circumstances.  The latter bit is actually reserved for mesh BSSes
according to Table 9-168 in 802.11-2016, so in fact it should not
be set.

wpa_supplicant sets these bits because the mesh and AP code share
the same implementation, but authsae does not.  As a result, some
meshconf updates from authsae which set only the NONHT_MIXED
protection bits were being rejected.

In order to avoid breaking userspace by changing the rules again,
simply accept the values with or without the bits set, and mask
off the reserved bit to match the spec.

While in here, update the 802.11-2012 reference to 802.11-2016.

Fixes: 9757235f ("nl80211: correct checks for NL80211_MESHCONF_HT_OPMODE value")
Cc: Masashi Honma <masashi.honma@gmail.com>
Signed-off-by: NBob Copeland <bobcopeland@fb.com>
Reviewed-by: NMasashi Honma <masashi.honma@gmail.com>
Reviewed-by: NMasashi Honma <masashi.honma@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

On pre-emption enabled kernels the following print was being seen due to
missing local_bh_disable/local_bh_enable calls.  mac80211 assumes that
pre-emption is disabled in the data path.

    BUG: using smp_processor_id() in preemptible [00000000] code: iwd/517
    caller is __ieee80211_subif_start_xmit+0x144/0x210 [mac80211]
    [...]
    Call Trace:
    dump_stack+0x5c/0x80
    check_preemption_disabled.cold.0+0x46/0x51
    __ieee80211_subif_start_xmit+0x144/0x210 [mac80211]

Fixes: 91180649 ("mac80211: Add support for tx_control_port")
Signed-off-by: NDenis Kenzior <denkenz@gmail.com>
[commit message rewrite, fixes tag]
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

This is clearly a bug.

We need to set the DMA buffer size in the HW otherwise corruption can
occur when receiving packets.

This is probably not occuring because of small MTU values and because HW
has a default value internally (which currently is bigger than default
buffer size).
Signed-off-by: NJose Abreu <joabreu@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Vitor Soares <soares@synopsys.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The recent poll change may lead to stalls for non-blocking connecting
SMC sockets, since sock_poll_wait is no longer performed on the
internal CLC socket, but on the outer SMC socket.  kernel_connect() on
the internal CLC socket returns with -EINPROGRESS, but the wake up
logic does not work in all cases. If the internal CLC socket is still
in state TCP_SYN_SENT when polled, sock_poll_wait() from sock_poll()
does not sleep. It is supposed to sleep till the state of the internal
CLC socket switches to TCP_ESTABLISHED.

This problem triggered a redesign of the SMC nonblocking connect logic.
This patch introduces a connect worker covering all connect steps
followed by a wake up of socket waiters. It allows to get rid of all
delays and locks in smc_poll().

Fixes: c0129a06 ("smc: convert to ->poll_mask")
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Larry Brakmo proposal ( https://patchwork.ozlabs.org/patch/935233/
tcp: force cwnd at least 2 in tcp_cwnd_reduction) made us rethink
about our recent patch removing ~16 quick acks after ECN events.

tcp_enter_quickack_mode(sk, 1) makes sure one immediate ack is sent,
but in the case the sender cwnd was lowered to 1, we do not want
to have a delayed ack for the next packet we will receive.

Fixes: 522040ea ("tcp: do not aggressively quick ack after ECN events")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NNeal Cardwell <ncardwell@google.com>
Cc: Lawrence Brakmo <brakmo@fb.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

What we want here is to embed a user-space program into the kernel.
Instead of the complex ELF magic, let's simply wrap it in the assembly
with the '.incbin' directive.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On receving an incomplete message, the existing code stores the
remaining length of the cloned skb in the early_eaten field instead of
incrementing the value returned by __strp_recv. This defers invocation
of sock_rfree for the current skb until the next invocation of
__strp_recv, which returns early_eaten if early_eaten is non-zero.

This behavior causes a stall when the current message occupies the very
tail end of a massive skb, and strp_peek/need_bytes indicates that the
remainder of the current message has yet to arrive on the socket. The
TCP receive buffer is totally full, causing the TCP window to go to
zero, so the remainder of the message will never arrive.

Incrementing the value returned by __strp_recv by the amount otherwise
stored in early_eaten prevents stalls of this nature.
Signed-off-by: NDoron Roberts-Kedes <doronrk@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
mlx5-fixes-2018-06-26

Fixes for mlx5 core and netdev driver:

Two fixes from Alex Vesker to address command interface issues
 - Race in command interface polling mode
 - Incorrect raw command length parsing

From Shay Agroskin, Fix wrong size allocation for QoS ETC TC regitster.

From Or Gerlitz and Eli Cohin, Address backward compatability issues for when
Eswitch capability is not advertised for the PF host driver
    - Fix required capability for manipulating MPFS
    - E-Switch, Disallow vlan/spoofcheck setup if not being esw manager
    - Avoid dealing with vport IB/eth representors if not being e-switch manager
    - E-Switch, Avoid setup attempt if not being e-switch manager
    - Don't attempt to dereference the ppriv struct if not being eswitch manager
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

fib_tests.sh became non-executable at some point. This is
what happens:
  selftests: net: fib_tests.sh: Warning: file fib_tests.sh is
  not executable, correct this.
  not ok 1..11 selftests: net: fib_tests.sh [FAIL]

Fixes: d69faad7 ("selftests: fib_tests: Add prefix route tests with metric")
Signed-off-by: NDaniel Díaz <daniel.diaz@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jesper Dangaard Brouer says:

====================
xdp: don't mix XDP_TX and XDP_REDIRECT flush ops

Fix driver logic that are combining XDP_TX flush and XDP_REDIRECT map
flushing.  These are two different XDP xmit modes, and it is clearly
wrong to invoke both types of flush operations when only one of the
XDP xmit modes is used.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver was combining XDP_TX virtqueue_kick and XDP_REDIRECT
map flushing (xdp_do_flush_map).  This is suboptimal, these two
flush operations should be kept separate.

The suboptimal behavior was introduced in commit 9267c430
("virtio-net: add missing virtqueue kick when flushing packets").

Fixes: 9267c430 ("virtio-net: add missing virtqueue kick when flushing packets")
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver was combining the XDP_TX tail flush and XDP_REDIRECT
map flushing (xdp_do_flush_map).  This is suboptimal, these two
flush operations should be kept separate.

It looks like the mistake was copy-pasted from ixgbe.

Fixes: d9314c47 ("i40e: add support for XDP_REDIRECT")
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Acked-by: NBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver was combining the XDP_TX tail flush and XDP_REDIRECT
map flushing (xdp_do_flush_map).  This is suboptimal, these two
flush operations should be kept separate.

Fixes: 11393cc9 ("xdp: Add batching support to redirect map")
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The macb driver currently crashes on at91rm9200 with the following trace:

Unable to handle kernel NULL pointer dereference at virtual address 00000014
[...]
[<c031da44>] (macb_rx_desc) from [<c031f2bc>] (at91ether_open+0x2e8/0x3f8)
[<c031f2bc>] (at91ether_open) from [<c041e8d8>] (__dev_open+0x120/0x13c)
[<c041e8d8>] (__dev_open) from [<c041ec08>] (__dev_change_flags+0x17c/0x1a8)
[<c041ec08>] (__dev_change_flags) from [<c041ec4c>] (dev_change_flags+0x18/0x4c)
[<c041ec4c>] (dev_change_flags) from [<c07a5f4c>] (ip_auto_config+0x220/0x10b0)
[<c07a5f4c>] (ip_auto_config) from [<c000a4fc>] (do_one_initcall+0x78/0x18c)
[<c000a4fc>] (do_one_initcall) from [<c0783e50>] (kernel_init_freeable+0x184/0x1c4)
[<c0783e50>] (kernel_init_freeable) from [<c0574d70>] (kernel_init+0x8/0xe8)
[<c0574d70>] (kernel_init) from [<c00090e0>] (ret_from_fork+0x14/0x34)

Solve that by initializing bp->queues[0].bp in at91ether_init (as is done
in macb_init).

Fixes: ae1f2a56 ("net: macb: Added support for many RX queues")
Signed-off-by: NAlexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: NNicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With the brand-new syntax extension of Kconfig, we can directly
check the compiler capability in the configuration phase.

If the cc-can-link.sh fails, the BPFILTER_UMH is automatically
hidden by the dependency.

I also deleted 'default n', which is no-op.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Following warning is seen when rmmod hinic. This is because affinity
value is not reset before calling free_irq(). This patch fixes it.

[   55.181232] WARNING: CPU: 38 PID: 19589 at kernel/irq/manage.c:1608
__free_irq+0x2aa/0x2c0

Fixes: 352f58b0 ("net-next/hinic: Set Rxq irq to specific cpu for NUMA")
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pablo Neira Ayuso says:

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

The following patchset contains Netfilter fixes for your net tree:

1) Missing netlink attribute validation in nf_queue, uncovered by KASAN,
   from Eric Dumazet.

2) Use pointer to sysctl table, save us 192 bytes of memory per netns.
   Also from Eric.

3) Possible use-after-free when removing conntrack helper modules due
   to missing synchronize RCU call. From Taehee Yoo.

4) Fix corner case in systcl writes to nf_log that lead to appending
   data to uninitialized buffer, from Jann Horn.

5) Jann Horn says we may indefinitely block other users of nf_log_mutex
   if a userspace access in proc_dostring() blocked e.g. due to a
   userfaultfd.

6) Fix garbage collection race for unconfirmed conntrack entries,
   from Florian Westphal.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sizeof() will return unsigned value so in the error check
negative error code will be always larger than sizeof().

Fixes: a0d8e02c ("nfp: add support for reading nffw info")
Signed-off-by: NChengguang Xu <cgxu519@gmx.com>
Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jakub Kicinski says:

====================
nfp: MPLS and shared blocks TC offload fixes

This series brings two fixes to TC filter/action offload code.
Pieter fixes matching MPLS packets when the match is purely on
the MPLS ethertype and none of the MPLS fields are used.
John provides a fix for offload of shared blocks.  Unfortunately,
with shared blocks there is currently no guarantee that filters
which were added by the core will be removed before block unbind.
Our simple fix is to not support offload of rules on shared blocks
at all, a revert of this fix will be send for -next once the
reoffload infrastructure lands.  The shared blocks became important
as we are trying to use them for bonding offload (managed from user
space) and lack of remove calls leads to resource leaks.

v2:
 - fix build error reported by kbuild bot due to missing
   tcf_block_shared() helper.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

TC shared blocks allow multiple qdiscs to be grouped together and filters
shared between them. Currently the chains of filters attached to a block
are only flushed when the block is removed. If a qdisc is removed from a
block but the block still exists, flow del messages are not passed to the
callback registered for that qdisc. For the NFP, this presents the
possibility of rules still existing in hw when they should be removed.

Prevent binding to shared blocks until the kernel can send per qdisc del
messages when block unbinds occur.

tcf_block_shared() was not used outside of the core until now, so also
add an empty implementation for builds with CONFIG_NET_CLS=n.

Fixes: 48617387 ("net: sched: introduce shared filter blocks infrastructure")
Signed-off-by: NJohn Hurley <john.hurley@netronome.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previously it was not possible to distinguish between mpls ether types and
other ether types. This leads to incorrect classification of offloaded
filters that match on mpls ether type. For example the following two
filters overlap:

 # tc filter add dev eth0 parent ffff: \
    protocol 0x8847 flower \
    action mirred egress redirect dev eth1

 # tc filter add dev eth0 parent ffff: \
    protocol 0x0800 flower \
    action mirred egress redirect dev eth2

The driver now correctly includes the mac_mpls layer where HW stores mpls
fields, when it detects an mpls ether type. It also sets the MPLS_Q bit to
indicate that the filter should match mpls packets.

Fixes: bb055c19 ("nfp: add mpls match offloading support")
Signed-off-by: NPieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: NSimon Horman <simon.horman@netronome.com>
Reviewed-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Two rules with different values of suppress_prefix or suppress_ifgroup
are not the same. This fixes an -EEXIST when running:

   $ ip -4 rule add table main suppress_prefixlength 0
Signed-off-by: NJason A. Donenfeld <Jason@zx2c4.com>
Fixes: f9d4b0c1 ("fib_rules: move common handling of newrule delrule msgs into fib_nl2rule")
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The RDS core module creates rds_connections based on callbacks
from rds_loop_transport when sending/receiving packets to local
addresses.

These connections will need to be cleaned up when they are
created from a netns that is not init_net, and that netns is deleted.

Add the changes aligned with the changes from
commit ebeeb1ad ("rds: tcp: use rds_destroy_pending() to synchronize
netns/module teardown and rds connection/workq management") for
rds_loop_transport

Reported-and-tested-by: syzbot+4c20b3866171ce8441d2@syzkaller.appspotmail.com
Acked-by: NSantosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: NSowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The command interface can work in two modes: Events and Polling.
In the general case, each time we invoke a command, a work is
queued to handle it.

When working in events, the interrupt handler completes the
command execution. On the other hand, when working in polling
mode, the work itself completes it.

Due to a bug in the work handler, a command could have been
completed by the interrupt handler, while the work handler
hasn't finished yet, causing the it to complete once again
if the command interface mode was changed from Events to
polling after the interrupt handler was called.

mlx5_unload_one()
        mlx5_stop_eqs()
                // Destroy the EQ before cmd EQ
                ...cmd_work_handler()
                        write_doorbell()
                        --> EVENT_TYPE_CMD
                                mlx5_cmd_comp_handler() // First free
                                        free_ent(cmd, ent->idx)
                                        complete(&ent->done)

        <-- mlx5_stop_eqs //cmd was complete
                // move to polling before destroying the last cmd EQ
                mlx5_cmd_use_polling()
                        cmd->mode = POLL;

                --> cmd_work_handler (continues)
                        if (cmd->mode == POLL)
                                mlx5_cmd_comp_handler() // Double free

The solution is to store the cmd->mode before writing the doorbell.

Fixes: e126ba97 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Signed-off-by: NAlex Vesker <valex@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

The NULL character was not set correctly for the string containing
the command length, this caused failures reading the output of the
command due to a random length. The fix is to initialize the output
length string.

Fixes: e126ba97 ("mlx5: Add driver for Mellanox Connect-IB adapters")
Signed-off-by: NAlex Vesker <valex@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

The driver allocates wrong size (due to wrong struct name) when issuing
a query/set request to NIC's register.

Fixes: d8880795 ("net/mlx5e: Implement DCBNL IEEE max rate")
Signed-off-by: NShay Agroskin <shayag@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

Manipulating of the MPFS requires eswitch manager capabilities.

Fixes: eeb66cdb ('net/mlx5: Separate between E-Switch and MPFS')
Signed-off-by: NEli Cohen <eli@mellanox.com>
Reviewed-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

In smartnic env, if the host (PF) driver is not an e-switch manager, we
are not allowed to apply eswitch ports setups such as vlan (VST),
spoof-checks, min/max rate or state.

Make sure we are eswitch manager when coming to issue these callbacks
and err otherwise.

Also fix the definition of ESW_ALLOWED to rely on eswitch_manager
capability and on the vport_group_manger.

Operations on the VF nic vport context, such as setting a mac or reading
the vport counters are allowed to the PF in this scheme.

The modify nic vport guid code was modified to omit checking the
nic_vport_node_guid_modify eswitch capability.
The reason for doing so is that modifying node guid requires vport group
manager capability, and there's no need to check further capabilities.

1. set_vf_vlan     - disallowed
2. set_vf_spoofchk - disallowed
3. set_vf_mac      - allowed
4. get_vf_config   - allowed
5. set_vf_trust    - disallowed
6. set_vf_rate     - disallowed
7. get_vf_stat     - allowed
8. set_vf_link_state - disallowed

Fixes: f942380c ('net/mlx5: E-Switch, Vport ingress/egress ACLs rules for spoofchk')
Signed-off-by: NEli Cohen <eli@mellanox.com>
Reviewed-by: NOr Gerlitz <ogerlitz@mellanox.com>
Tested-by: NOr Gerlitz <ogerlitz@mellanox.com>

In smartnic env, the host (PF) driver might not be an e-switch
manager, hence the switchdev mode representors are running on
the embedded cpu (EC) and not at the host.

As such, we should avoid dealing with vport representors if
not being esw manager.

Fixes: b5ca15ad ('IB/mlx5: Add proper representors support')
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: NEli Cohen <eli@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

In smartnic env, the host (PF) driver might not be an e-switch
manager, hence the switchdev mode representors are running on
the embedded cpu (EC) and not at the host.

As such, we should avoid dealing with vport representors if
not being esw manager.

While here, make sure to disallow eswitch switchdev related
setups through devlink if we are not esw managers.

Fixes: cb67b832 ('net/mlx5e: Introduce SRIOV VF representors')
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: NEli Cohen <eli@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

In smartnic env, the host (PF) driver might not be an e-switch
manager, hence the FW will err on driver attempts to deal with
setting/unsetting the eswitch and as a result the overall setup
of sriov will fail.

Fix that by avoiding the operation if e-switch management is not
allowed for this driver instance. While here, move to use the
correct name for the esw manager capability name.

Fixes: 81848731 ('net/mlx5: E-Switch, Add SR-IOV (FDB) support')
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Reported-by: NGuy Kushnir <guyk@mellanox.com>
Reviewed-by: NEli Cohen <eli@melloanox.com>
Tested-by: NEli Cohen <eli@melloanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

The check for cpu hit statistics was not returning immediate false for
any non vport rep netdev and hence we crashed (say on mlx5 probed VFs) if
user-space tool was calling into any possible netdev in the system.

Fix that by doing a proper check before dereferencing.

Fixes: 1d447a39 ('net/mlx5e: Extendable vport representor netdev private data')
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Reported-by: NEli Cohen <eli@melloanox.com>
Reviewed-by: NEli Cohen <eli@melloanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>

Yi-Hung Wei and Justin Pettit found a race in the garbage collection scheme
used by nf_conncount.

When doing list walk, we lookup the tuple in the conntrack table.
If the lookup fails we remove this tuple from our list because
the conntrack entry is gone.

This is the common cause, but turns out its not the only one.
The list entry could have been created just before by another cpu, i.e. the
conntrack entry might not yet have been inserted into the global hash.

The avoid this, we introduce a timestamp and the owning cpu.
If the entry appears to be stale, evict only if:
 1. The current cpu is the one that added the entry, or,
 2. The timestamp is older than two jiffies

The second constraint allows GC to be taken over by other
cpu too (e.g. because a cpu was offlined or napi got moved to another
cpu).

We can't pretend the 'doubtful' entry wasn't in our list.
Instead, when we don't find an entry indicate via IS_ERR
that entry was removed ('did not exist' or withheld
('might-be-unconfirmed').

This most likely also fixes a xt_connlimit imbalance earlier reported by
Dmitry Andrianov.

Cc: Dmitry Andrianov <dmitry.andrianov@alertme.com>
Reported-by: NJustin Pettit <jpettit@vmware.com>
Reported-by: NYi-Hung Wei <yihung.wei@gmail.com>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Acked-by: NYi-Hung Wei <yihung.wei@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

The old code would indefinitely block other users of nf_log_mutex if
a userspace access in proc_dostring() blocked e.g. due to a userfaultfd
region. Fix it by moving proc_dostring() out of the locked region.

This is a followup to commit 266d07cb ("netfilter: nf_log: fix
sleeping function called from invalid context"), which changed this code
from using rcu_read_lock() to taking nf_log_mutex.

Fixes: 266d07cb ("netfilter: nf_log: fix sleeping function calle[...]")
Signed-off-by: NJann Horn <jannh@google.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

When proc_dostring() is called with a non-zero offset in strict mode, it
doesn't just write to the ->data buffer, it also reads. Make sure it
doesn't read uninitialized data.

Fixes: c6ac37d8 ("netfilter: nf_log: fix error on write NONE to [...]")
Signed-off-by: NJann Horn <jannh@google.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

Dave Stevenson says:

====================
lan78xx minor fixes

This is a small set of patches for the Microchip LAN78xx chip,
as used in the Raspberry Pi 3B+.
The main debug/discussion was on
https://github.com/raspberrypi/linux/issues/2458

Initial symptoms were that VLANs were very unreliable.
A couple of things were found:
- firstly that the hardware timeout value set failed to
  take into account the VLAN tag, so a full MTU packet
  would be timed out.
- second was that regular checksum failures were being
  reported. Disabling checksum offload confirmed that
  the checksums were valid, and further experimentation
  identified that it was only if the VLAN tags were being
  passed through to the kernel that there were issues.
  The hardware supports VLAN filtering and tag stripping,
  therefore those have been implemented (much of the work
  was already done), and the driver drops back to s/w
  checksums should the choice be made not to use the h/w
  VLAN stripping.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>