Some Hypervisors detach VFs from VMs by instantly causing an FLR event
to be generated for a VF.

In the mlx4 case, this will cause that VF's comm channel to be disabled
before the VM has an opportunity to invoke the VF device's "shutdown"
method.

For such Hypervisors, there is a race condition between the VF's
shutdown method and its internal-error detection/reset thread.

The internal-error detection/reset thread (which runs every 5 seconds) also
detects a disabled comm channel. If the internal-error detection/reset
flow wins the race, we still get delays (while that flow tries repeatedly
to detect comm-channel recovery).

The cited commit fixed the command timeout problem when the
internal-error detection/reset flow loses the race.

This commit avoids the unneeded delays when the internal-error
detection/reset flow wins.

Fixes: d585df1c ("net/mlx4_core: Avoid command timeouts during VF driver device shutdown")
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Reported-by: Simon Xiao <sixiao@microsoft.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Simon Wunderlich says:

====================
Here are two batman-adv bugfixes:

 - Keep fragments equally sized, avoids some problems with too small fragments,
   by Sven Eckelmann

 - Initialize gateway class correctly when BATMAN V is compiled in,
   by Sven Eckelmann
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Added a case for OVS_TUNNEL_KEY_ATTR_PAD to the switch statement
in ip_tun_from_nlattr in order to prevent the default case
returning an error.

Fixes: b46f6ded ("libnl: nla_put_be64(): align on a 64-bit area")
Signed-off-by: Kris Murphy <kriskend@linux.vnet.ibm.com>
Acked-by: Joe Stringer <joe@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sowmini pointed out Dmitry's RTNL deadlock report to me, and it turns out
to be perfectly accurate - there are various error paths that miss unlock
of the RTNL.

To fix those, change the locking a bit to not be conditional in all those
nl80211_prepare_*_dump() functions, but make those require the RTNL to
start with, and fix the buggy error paths. This also let me use sparse
(by appropriately overriding the rtnl_lock/rtnl_unlock functions) to
validate the changes.

Cc: stable@vger.kernel.org
Reported-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

I mistakenly added the code to release sk->sk_frag in
sk_common_release() instead of sk_destruct()

TCP sockets using sk->sk_allocation == GFP_ATOMIC do no call
sk_common_release() at close time, thus leaking one (order-3) page.

iSCSI is using such sockets.

Fixes: 5640f768 ("net: use a per task frag allocator")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Newer hardware does not provide a cumulative payload length when multiple
descriptors are needed to handle the data. Once the MTU increases beyond
the size that can be handled by a single descriptor, the SKB does not get
built properly by the driver.

The driver will now calculate the size of the data buffers used by the
hardware.  The first buffer of the first descriptor is for packet headers
or packet headers and data when the headers can't be split. Subsequent
descriptors in a multi-descriptor chain will not use the first buffer. The
second buffer is used by all the descriptors in the chain for payload data.
Based on whether the driver is processing the first, intermediate, or last
descriptor it can calculate the buffer usage and build the SKB properly.

Tested and verified on both old and new hardware.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Suspending the PHY would be putting it in a low power state where it
may no longer allow us to do Wake-on-LAN.

Fixes: cc013fb4 ("net: bcmgenet: correctly suspend and resume PHY device")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

macvlan.c file seems to be both in VLAN and MACVLAN DRIVER, so remove
the MACVLAN DRIVER since this is redundant.

I propose with this patch to remove the VLAN (802.1Q) entry so this just
falls into the NETWORKING [GENERAL].
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pablo Neira Ayuso says:

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

The following patchset contains Netfilter fixes for your net tree, a
rather large batch of fixes targeted to nf_tables, conntrack and bridge
netfilter. More specifically, they are:

1) Don't track fragmented packets if the socket option IP_NODEFRAG is set.
   From Florian Westphal.

2) SCTP protocol tracker assumes that ICMP error messages contain the
   checksum field, what results in packet drops. From Ying Xue.

3) Fix inconsistent handling of AH traffic from nf_tables.

4) Fix new bitmap set representation with big endian. Fix mismatches in
   nf_tables due to incorrect big endian handling too. Both patches
   from Liping Zhang.

5) Bridge netfilter doesn't honor maximum fragment size field, cap to
   largest fragment seen. From Florian Westphal.

6) Fake conntrack entry needs to be aligned to 8 bytes since the 3 LSB
   bits are now used to store the ctinfo. From Steven Rostedt.

7) Fix element comments with the bitmap set type. Revert the flush
   field in the nft_set_iter structure, not required anymore after
   fixing up element comments.

8) Missing error on invalid conntrack direction from nft_ct, also from
   Liping Zhang.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

When dealing with ipv6 source tunnel key address attribute
(OVS_TUNNEL_KEY_ATTR_IPV6_SRC) we are wrongly setting the tunnel
dst ip, fix that.

Fixes: 6b26ba3a ('openvswitch: netlink attributes for IPv6 tunneling')
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reported-by: Paul Blakey <paulb@mellanox.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Acked-by: Joe Stringer <joe@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes netdev->features for Extended Socket network device.

Currently Extended Socket network device's netdev->feature claims
NETIF_F_HW_CSUM, however this is completely wrong. There's no feature
of checksum offloading.
That causes invalid TCP/UDP checksum and packet rejection when IP
forwarding from Extended Socket network device to other network device.

NETIF_F_HW_CSUM should be omitted.
Signed-off-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull SCSI fixes from James Bottomley:
 "This is a rather large set of fixes. The bulk are for lpfc correcting
  a lot of issues in the new NVME driver code which just went in in the
  merge window.

  The others are:

   - fix a hang in the vmware paravirt driver caused by incorrect
     handling of the new MSI vector allocation

   - long standing bug in storvsc, which recent block changes turned
     from being a harmless annoyance into a hang

   - yet more fallout (in mpt3sas) from the changes to device blocking

  The remainder are small fixes and updates"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (34 commits)
  scsi: lpfc: Add shutdown method for kexec
  scsi: storvsc: Workaround for virtual DVD SCSI version
  scsi: lpfc: revise version number to 11.2.0.10
  scsi: lpfc: code cleanups in NVME initiator discovery
  scsi: lpfc: code cleanups in NVME initiator base
  scsi: lpfc: correct rdp diag portnames
  scsi: lpfc: remove dead sli3 nvme code
  scsi: lpfc: correct double print
  scsi: lpfc: Rename LPFC_MAX_EQ_DELAY to LPFC_MAX_EQ_DELAY_EQID_CNT
  scsi: lpfc: Rework lpfc Kconfig for NVME options
  scsi: lpfc: add transport eh_timed_out reference
  scsi: lpfc: Fix eh_deadline setting for sli3 adapters.
  scsi: lpfc: add NVME exchange aborts
  scsi: lpfc: Fix nvme allocation bug on failed nvme_fc_register_localport
  scsi: lpfc: Fix IO submission if WQ is full
  scsi: lpfc: Fix NVME CMD IU byte swapped word 1 problem
  scsi: lpfc: Fix RCTL value on NVME LS request and response
  scsi: lpfc: Fix crash during Hardware error recovery on SLI3 adapters
  scsi: lpfc: fix missing spin_unlock on sql_list_lock
  scsi: lpfc: don't dereference dma_buf->iocbq before null check
  ...

Pull gfs2 fix from Bob Peterson:
 "This is an emergency patch for 4.11-rc3

  The GFS2 developers uncovered a really nasty problem that can lead to
  random corruption and kernel panic, much like the last one. Andreas
  Gruenbacher wrote a simple one-line patch to fix the problem."

* tag 'gfs2-4.11-rc3.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  gfs2: Avoid alignment hole in struct lm_lockname

Pull crypto fixes from Herbert Xu:

 - self-test failure of crc32c on powerpc

 - regressions of ecb(aes) when used with xts/lrw in s5p-sss

 - a number of bugs in the omap RNG driver

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: s5p-sss - Fix spinlock recursion on LRW(AES)
  hwrng: omap - Do not access INTMASK_REG on EIP76
  hwrng: omap - use devm_clk_get() instead of of_clk_get()
  hwrng: omap - write registers after enabling the clock
  crypto: s5p-sss - Fix completing crypto request in IRQ handler
  crypto: powerpc - Fix initialisation of crc32c context

We should jump to invoke __nft_ct_set_destroy() instead of just
return error.

Fixes: edee4f1e ("netfilter: nft_ct: add zone id set support")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Commit 88ffbf3e switches to using rhashtables for glocks, hashing over
the entire struct lm_lockname instead of its individual fields.  On some
architectures, struct lm_lockname contains a hole of uninitialized
memory due to alignment rules, which now leads to incorrect hash values.
Get rid of that hole.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
CC: <stable@vger.kernel.org> #v4.3+

Pull networking fixes from David Miller:

 1) Ensure that mtu is at least IPV6_MIN_MTU in ipv6 VTI tunnel driver,
    from Steffen Klassert.

 2) Fix crashes when user tries to get_next_key on an LPM bpf map, from
    Alexei Starovoitov.

 3) Fix detection of VLAN fitlering feature for bnx2x VF devices, from
    Michal Schmidt.

 4) We can get a divide by zero when TCP socket are morphed into
    listening state, fix from Eric Dumazet.

 5) Fix socket refcounting bugs in skb_complete_wifi_ack() and
    skb_complete_tx_timestamp(). From Eric Dumazet.

 6) Use after free in dccp_feat_activate_values(), also from Eric
    Dumazet.

 7) Like bonding team needs to use ETH_MAX_MTU as netdev->max_mtu, from
    Jarod Wilson.

 8) Fix use after free in vrf_xmit(), from David Ahern.

 9) Don't do UDP Fragmentation Offload on IPComp ipsec packets, from
    Alexey Kodanev.

10) Properly check napi_complete_done() return value in order to decide
    whether to re-enable IRQs or not in amd-xgbe driver, from Thomas
    Lendacky.

11) Fix double free of hwmon device in marvell phy driver, from Andrew
    Lunn.

12) Don't crash on malformed netlink attributes in act_connmark, from
    Etienne Noss.

13) Don't remove routes with a higher metric in ipv6 ECMP route replace,
    from Sabrina Dubroca.

14) Don't write into a cloned SKB in ipv6 fragmentation handling, from
    Florian Westphal.

15) Fix routing redirect races in dccp and tcp, basically the ICMP
    handler can't modify the socket's cached route in it's locked by the
    user at this moment. From Jon Maxwell.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (108 commits)
  qed: Enable iSCSI Out-of-Order
  qed: Correct out-of-bound access in OOO history
  qed: Fix interrupt flags on Rx LL2
  qed: Free previous connections when releasing iSCSI
  qed: Fix mapping leak on LL2 rx flow
  qed: Prevent creation of too-big u32-chains
  qed: Align CIDs according to DORQ requirement
  mlxsw: reg: Fix SPVMLR max record count
  mlxsw: reg: Fix SPVM max record count
  net: Resend IGMP memberships upon peer notification.
  dccp: fix memory leak during tear-down of unsuccessful connection request
  tun: fix premature POLLOUT notification on tun devices
  dccp/tcp: fix routing redirect race
  ucc/hdlc: fix two little issue
  vxlan: fix ovs support
  net: use net->count to check whether a netns is alive or not
  bridge: drop netfilter fake rtable unconditionally
  ipv6: avoid write to a possibly cloned skb
  net: wimax/i2400m: fix NULL-deref at probe
  isdn/gigaset: fix NULL-deref at probe
  ...

Pull cgroup fixes from Tejun Heo:
 "Three cgroup fixes.  Nothing critical:

   - the pids controller could trigger suspicious RCU warning
     spuriously. Fixed.

   - in the debug controller, %p -> %pK to protect kernel pointer
     from getting exposed.

   - documentation formatting fix"

* 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroups: censor kernel pointer in debug files
  cgroup/pids: remove spurious suspicious RCU usage warning
  cgroup: Fix indenting in PID controller documentation

Pull libata fixes from Tejun Heo:
 "Three libata fixes:

   - fix for a circular reference bug in sysfs code which prevented
     pata_legacy devices from being released after probe failure, which
     in turn prevented devres from releasing the associated resources.

   - drop spurious WARN in the command issue path which can be triggered
     by a legitimate passthrough command.

   - an ahci_qoriq specific fix"

* 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
  ahci: qoriq: correct the sata ecc setting error
  libata: drop WARN from protocol error in ata_sff_qc_issue()
  libata: transport: Remove circular dependency at free time

Pull workqueue fix from Tejun Heo:
 "If a delayed work is queued with NULL @wq, workqueue code explodes
  after the timer expires at which point it's difficult to tell who the
  culprit was.

  This actually happened and the offender was net/smc this time.

  Add an explicit sanity check for it in the queueing path"

* 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: trigger WARN if queue_delayed_work() is called with NULL @wq

Pull percpu fixes from Tejun Heo:

 - the allocation path was updating pcpu_nr_empty_pop_pages without the
   required locking which can lead to incorrect handling of empty chunks
   (e.g. keeping too many around), which is buggy but shouldn't lead to
   critical failures. Fixed by adding the locking

 - a trivial patch to drop an unused param from pcpu_get_pages()

* 'for-4.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: remove unused chunk_alloc parameter from pcpu_get_pages()
  percpu: acquire pcpu_lock when updating pcpu_nr_empty_pop_pages

Yuval Mintz says:

====================
qed: Fixes series

This address several different issues in qed.
The more significant portions:

Patch #1 would cause timeout when qedr utilizes the highest
CIDs availble for it [or when future qede adapters would utilize
queues in some constellations].

Patch #4 fixes a leak of mapped addresses; When iommu is enabled,
offloaded storage protocols might eventually run out of resources
and fail to map additional buffers.

Patches #6,#7 were missing in the initial iSCSI infrastructure
submissions, and would hamper qedi's stability when it reaches
out-of-order scenarios.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Missing in the initial submission, qed fails to propagate qedi's
request to enable OOO to firmware.

Fixes: fc831825 ("qed: Add support for hardware offloaded iSCSI")
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Need to set the number of entries in database, otherwise the logic
would quickly surpass the array.

Fixes: 1d6cff4f ("qed: Add iSCSI out of order packet handling")
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Before iterating over the the LL2 Rx ring, the ring's
spinlock is taken via spin_lock_irqsave().
The actual processing of the packet [including handling
by the protocol driver] is done without said lock,
so qed releases the spinlock and re-claims it afterwards.

Problem is that the final spin_lock_irqrestore() at the end
of the iteration uses the original flags saved from the
initial irqsave() instead of the flags from the most recent
irqsave(). So it's possible that the interrupt status would
be incorrect at the end of the processing.

Fixes: 0a7fb11c ("qed: Add Light L2 support");
CC: Ram Amrani <Ram.Amrani@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fixes: fc831825 ("qed: Add support for hardware offloaded iSCSI")
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When receiving an Rx LL2 packet, qed fails to unmap the previous buffer.

Fixes: 0a7fb11c ("qed: Add Light L2 support");
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Current Logic would allow the creation of a chain with U32_MAX + 1
elements, when the actual maximum supported by the driver infrastructure
is U32_MAX.

Fixes: a91eb52a ("qed: Revisit chain implementation")
Signed-off-by: Tomer Tayar <Tomer.Tayar@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The Doorbell HW block can be configured at a granularity
of 16 x CIDs, so we need to make sure that the actual number
of CIDs configured would be a multiplication of 16.

Today, when RoCE is enabled - given that the number is unaligned,
doorbelling the higher CIDs would fail to reach the firmware and
would eventually timeout.

Fixes: dbb799c3 ("qed: Initialize hardware for new protocols")
Signed-off-by: Ram Amrani <Ram.Amrani@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jiri Pirko says:

====================
mlxsw: Couple of fixes

Couple or small fixes.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The num_rec field is 8 bit, so the maximal count number is 255.
This fixes vlans learning not being enabled for wider ranges than 255.

Fixes: a4feea74 ("mlxsw: reg: Add Switch Port VLAN MAC Learning register definition")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The num_rec field is 8 bit, so the maximal count number is 255. This
fixes vlans not being enabled for wider ranges than 255.

Fixes: b2e345f9 ("mlxsw: reg: Add Switch Port VID and Switch Port VLAN Membership registers definitions")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When we notify peers of potential changes,  it's also good to update
IGMP memberships.  For example, during VM migration, updating IGMP
memberships will redirect existing multicast streams to the VM at the
new location.
Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch fixes a memory leak, which happens if the connection request
is not fulfilled between parsing the DCCP options and handling the SYN
(because e.g. the backlog is full), because we forgot to free the
list of ack vectors.
Reported-by: Jianwen Ji <jiji@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

aszlig observed failing ssh tunnels (-w) during initialization since
commit cc9da6cc ("ipv6: addrconf: use stable address generator for
ARPHRD_NONE"). We already had reports that the mentioned commit breaks
Juniper VPN connections. I can't clearly say that the Juniper VPN client
has the same problem, but it is worth a try to hint to this patch.

Because of the early generation of link local addresses, the kernel now
can start asking for routers on the local subnet much earlier than usual.
Those router solicitation packets arrive inside the ssh channels and
should be transmitted to the tun fd before the configuration scripts
might have upped the interface and made it ready for transmission.

ssh polls on the interface and receives back a POLL_OUT. It tries to send
the earily router solicitation packet to the tun interface.  Unfortunately
it hasn't been up'ed yet by config scripts, thus failing with -EIO. ssh
doesn't retry again and considers the tun interface broken forever.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=121131
Fixes: cc9da6cc ("ipv6: addrconf: use stable address generator for ARPHRD_NONE")
Cc: Bjørn Mork <bjorn@mork.no>
Reported-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Reported-by: Jonas Lippuner <jonas@lippuner.ca>
Cc: Jonas Lippuner <jonas@lippuner.ca>
Reported-by: aszlig <aszlig@redmoonstudios.org>
Cc: aszlig <aszlig@redmoonstudios.org>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

As Eric Dumazet pointed out this also needs to be fixed in IPv6.
v2: Contains the IPv6 tcp/Ipv6 dccp patches as well.

We have seen a few incidents lately where a dst_enty has been freed
with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that
dst_entry. If the conditions/timings are right a crash then ensues when the
freed dst_entry is referenced later on. A Common crashing back trace is:

 #8 [] page_fault at ffffffff8163e648
    [exception RIP: __tcp_ack_snd_check+74]
.
.
 #9 [] tcp_rcv_established at ffffffff81580b64
#10 [] tcp_v4_do_rcv at ffffffff8158b54a
#11 [] tcp_v4_rcv at ffffffff8158cd02
#12 [] ip_local_deliver_finish at ffffffff815668f4
#13 [] ip_local_deliver at ffffffff81566bd9
#14 [] ip_rcv_finish at ffffffff8156656d
#15 [] ip_rcv at ffffffff81566f06
#16 [] __netif_receive_skb_core at ffffffff8152b3a2
#17 [] __netif_receive_skb at ffffffff8152b608
#18 [] netif_receive_skb at ffffffff8152b690
#19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3]
#20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3]
#21 [] net_rx_action at ffffffff8152bac2
#22 [] __do_softirq at ffffffff81084b4f
#23 [] call_softirq at ffffffff8164845c
#24 [] do_softirq at ffffffff81016fc5
#25 [] irq_exit at ffffffff81084ee5
#26 [] do_IRQ at ffffffff81648ff8

Of course it may happen with other NIC drivers as well.

It's found the freed dst_entry here:

 224 static bool tcp_in_quickack_mode(struct sock *sk)↩
 225 {↩
 226 ▹       const struct inet_connection_sock *icsk = inet_csk(sk);↩
 227 ▹       const struct dst_entry *dst = __sk_dst_get(sk);↩
 228 ↩
 229 ▹       return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩
 230 ▹       ▹       (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩
 231 }↩

But there are other backtraces attributed to the same freed dst_entry in
netfilter code as well.

All the vmcores showed 2 significant clues:

- Remote hosts behind the default gateway had always been redirected to a
different gateway. A rtable/dst_entry will be added for that host. Making
more dst_entrys with lower reference counts. Making this more probable.

- All vmcores showed a postitive LockDroppedIcmps value, e.g:

LockDroppedIcmps                  267

A closer look at the tcp_v4_err() handler revealed that do_redirect() will run
regardless of whether user space has the socket locked. This can result in a
race condition where the same dst_entry cached in sk->sk_dst_entry can be
decremented twice for the same socket via:

do_redirect()->__sk_dst_check()-> dst_release().

Which leads to the dst_entry being prematurely freed with another socket
pointing to it via sk->sk_dst_cache and a subsequent crash.

To fix this skip do_redirect() if usespace has the socket locked. Instead let
the redirect take place later when user space does not have the socket
locked.

The dccp/IPv6 code is very similar in this respect, so fixing it there too.

As Eric Garver pointed out the following commit now invalidates routes. Which
can set the dst->obsolete flag so that ipv4_dst_check() returns null and
triggers the dst_release().

Fixes: ceb33206 ("ipv4: Kill routes during PMTU/redirect updates.")
Cc: Eric Garver <egarver@redhat.com>
Cc: Hannes Sowa <hsowa@redhat.com>
Signed-off-by: Jon Maxwell <jmaxwell37@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1. modify bd_status from u32 to u16 in function hdlc_rx_done,
because bd_status register is 16bits
2. write bd_length register before writing bd_status register
Signed-off-by: Zhao Qiang <qiang.zhao@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull some more powerpc fixes from Michael Ellerman:
 "The main item is the addition of the Power9 Machine Check handler.
  This was delayed to make sure some details were correct, and is as
  minimal as possible.

  The rest is small fixes, two for the Power9 PMU, two dealing with
  obscure toolchain problems, two for the PowerNV IOMMU code (used by
  VFIO), and one to fix a crash on 32-bit machines with macio devices
  due to missing dma_ops.

  Thanks to:
    Alexey Kardashevskiy, Cyril Bur, Larry Finger, Madhavan Srinivasan,
    Nicholas Piggin"

* tag 'powerpc-4.11-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/64s: POWER9 machine check handler
  powerpc/64s: allow machine check handler to set severity and initiator
  powerpc/64s: fix handling of non-synchronous machine checks
  powerpc/pmac: Fix crash in dma-mapping.h with NULL dma_ops
  powerpc/powernv/ioda2: Update iommu table base on ownership change
  powerpc/powernv/ioda2: Gracefully fail if too many TCE levels requested
  selftests/powerpc: Replace stxvx and lxvx with stxvd2x/lxvd2x
  powerpc/perf: Handle sdar_mode for marked event in power9
  powerpc/perf: Fix perf_get_data_addr() for power9 DD1
  powerpc/boot: Fix zImage TOC alignment

The required changes in the function vxlan_dev_create() were missing
in commit 8bcdc4f3.
The vxlan device is not registered anymore after this patch and the error
path causes an stack dump:
 WARNING: CPU: 3 PID: 1498 at net/core/dev.c:6713 rollback_registered_many+0x9d/0x3f0

Fixes: 8bcdc4f3 ("vxlan: add changelink support")
CC: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The previous idea was to check whether a net namespace is in
net_exit_list or not. It doesn't work, because net->exit_list is used in
__register_pernet_operations and __unregister_pernet_operations where
all namespaces are added to a temporary list to make cleanup in a error
case, so list_empty(&net->exit_list) always returns false.
Reported-by: Mantas Mikulėnas <grawity@gmail.com>
Fixes: 002d8a1a ("net: skip genenerating uevents for network namespaces that are exiting")
Signed-off-by: Andrei Vagin <avagin@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>