If the driver fails to properly prepare for the channel
switch, mac80211 will disconnect. If the CSA IE had mode
set to 1, it means that the clients are not allowed to send
any Tx on the current channel, and that includes the
deauthentication frame.

Make sure that we don't send the deauthentication frame in
this case.

In iwlwifi, this caused a failure to flush queues since the
firmware already closed the queues after having parsed the
CSA IE. Then mac80211 would wait until the deauthentication
frame would go out (drv_flush(drop=false)) and that would
never happen.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When performing a channel switch flow for a managed interface, the
flow did not update the bandwidth of the AP station and the rate
scale algorithm. In case of a channel width downgrade, this would
result with the rate scale algorithm using a bandwidth that does not
match the interface channel configuration.

Fix this by updating the AP station bandwidth and rate scaling algorithm
before the actual channel change in case of a bandwidth downgrade, or
after the actual channel change in case of a bandwidth upgrade.
Signed-off-by: Ilan Peer <ilan.peer@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

We hit a problem with iwlwifi that was caused by a bug in
mac80211. A bug in iwlwifi caused the firwmare to crash in
certain cases in channel switch. Because of that bug,
drv_pre_channel_switch would fail and trigger the restart
flow.
Now we had the hw restart worker which runs on the system's
workqueue and the csa_connection_drop_work worker that runs
on mac80211's workqueue that can run together. This is
obviously problematic since the restart work wants to
reconfigure the connection, while the csa_connection_drop_work
worker does the exact opposite: it tries to disconnect.

Fix this by cancelling the csa_connection_drop_work worker
in the restart worker.

Note that this can sound racy: we could have:

driver   iface_work   CSA_work   restart_work
+++++++++++++++++++++++++++++++++++++++++++++
              |
 <--drv_cs ---|
<FW CRASH!>
-CS FAILED-->
              |                       |
              |                 cancel_work(CSA)
           schedule                   |
           CSA work                   |
                         |            |
                        Race between those 2

But this is not possible because we flush the workqueue
in the restart worker before we cancel the CSA worker.
That would be bullet proof if we could guarantee that
we schedule the CSA worker only from the iface_work
which runs on the workqueue (and not on the system's
workqueue), but unfortunately we do have an instance
in which we schedule the CSA work outside the context
of the workqueue (ieee80211_chswitch_done).

Note also that we should probably cancel other workers
like beacon_connection_loss_work and possibly others
for different types of interfaces, at the very least,
IBSS should suffer from the exact same problem, but for
now, do the minimum to fix the actual bug that was actually
experienced and reproduced.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

In commit 9236c4523e5b ("mac80211: limit wmm params to comply
with ETSI requirements"), we have limited the WMM parameters to
comply with 802.11 and ETSI standard.  Mistakenly the TXOP value
was caluclated wrong.  Fix it by taking the minimum between
802.11 to ETSI to make sure we are not violating both.

Fixes: e552af05 ("mac80211: limit wmm params to comply with ETSI requirements")
Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The "chandef->center_freq1" variable is a u32 but "freq" is a u16 so we
are truncating away the high bits.  I noticed this bug because in commit
9cf0a0b4 ("cfg80211: Add support for 60GHz band channels 5 and 6")
we made "freq <= 56160 + 2160 * 6" a valid requency when before it was
only "freq <= 56160 + 2160 * 4" that was valid.  It introduces a static
checker warning:

    net/wireless/util.c:1571 ieee80211_chandef_to_operating_class()
    warn: always true condition '(freq <= 56160 + 2160 * 6) => (0-u16max <= 69120)'

But really we probably shouldn't have been truncating the high bits
away to begin with.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Initialize 'n' to 2 in order to take into account also the first
packet in the estimation of max_subframe limit for a given A-MSDU
since frag_tail pointer is NULL when ieee80211_amsdu_aggregate
routine analyzes the second frame.

Fixes: 6e0456b5 ("mac80211: add A-MSDU tx support")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

In the error path of changing the SKB headroom of the second
A-MSDU subframe, we would not account for the already-changed
length of the first frame that just got converted to be in
A-MSDU format and thus is a bit longer now.

Fix this by doing the necessary accounting.

It would be possible to reorder the operations, but that would
make the code more complex (to calculate the necessary pad),
and the headroom expansion should not fail frequently enough
to make that worthwhile.

Fixes: 6e0456b5 ("mac80211: add A-MSDU tx support")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Do not start to aggregate packets in a A-MSDU frame (converting the
first subframe to A-MSDU, adding the header) if max_tx_fragments or
max_amsdu_subframes limits are already exceeded by it. In particular,
this happens when drivers set the limit to 1 to avoid A-MSDUs at all.
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
[reword commit message to be more precise]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

nl80211_update_ft_ies() tried to validate NL80211_ATTR_IE with
is_valid_ie_attr() before dereferencing it, but that helper function
returns true in case of NULL pointer (i.e., attribute not included).
This can result to dereferencing a NULL pointer. Fix that by explicitly
checking that NL80211_ATTR_IE is included.

Fixes: 355199e0 ("cfg80211: Extend support for IEEE 802.11r Fast BSS Transition")
Signed-off-by: Arunk Khandavalli <akhandav@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

When building building AMSDU from non-linear SKB, we hit a
kernel panic when trying to push the padding to the tail.
Instead, put the padding at the head of the next subframe.
This also fixes the A-MSDU subframes to not have the padding
accounted in the length field and not have pad at all for
the last subframe, both required by the spec.

Fixes: 6e0456b5 ("mac80211: add A-MSDU tx support")
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Reviewed-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

IEEE 802.11-2016 14.10.8.3 HWMP sequence numbering says:
If it is a target mesh STA, it shall update its own HWMP SN to
maximum (current HWMP SN, target HWMP SN in the PREQ element) + 1
immediately before it generates a PREP element in response to a
PREQ element.
Signed-off-by: Yuan-Chi Pang <fu3mo6goo@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

freq_reg_info expects to get the frequency in kHz. Instead we
accidently pass it in MHz.  Thus, currently the function always
return ERR rule. Fix that.

Fixes: 50f32718 ("nl80211: Add wmm rule attribute to NL80211_CMD_GET_WIPHY dump command")
Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
[fix kHz/MHz in commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

TXOP (also known as Channel Occupancy Time) is u16 and should be
added using nla_put_u16 instead of u8, fix that.

Fixes: 50f32718 ("nl80211: Add wmm rule attribute to NL80211_CMD_GET_WIPHY dump command")
Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

User controls @idx which to be used as index of hwsim_world_regdom_custom.
So, It can be exploited via Spectre-like attack. (speculative execution)

This kind of attack leaks address of hwsim_world_regdom_custom,
It leads an attacker to bypass security mechanism such as KASLR.

So sanitize @idx before using it to prevent attack.

I leveraged strategy [1] to find and exploit this gadget.

[1] https://github.com/jinb-park/linux-exploit/tree/master/exploit-remaining-spectre-gadget/Signed-off-by: Jinbum Park <jinb.park7@gmail.com>
[johannes: unwrap URL]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

I changed the way mac80211 updates the PM state of the peer.
I forgot that we could also have multicast frames from the
peer and that those frame should of course not change the
PM state of the peer: A peer goes to power save when it
needs to scan, but it won't send the broadcast Probe Request
with the PM bit set.

This made us mark the peer as awake when it wasn't and then
Intel's firmware would fail to transmit because the peer is
asleep according to its database. The driver warned about
this and it looked like this:

 WARNING: CPU: 0 PID: 184 at /usr/src/linux-4.16.14/drivers/net/wireless/intel/iwlwifi/mvm/tx.c:1369 iwl_mvm_rx_tx_cmd+0x53b/0x860
 CPU: 0 PID: 184 Comm: irq/124-iwlwifi Not tainted 4.16.14 #1
 RIP: 0010:iwl_mvm_rx_tx_cmd+0x53b/0x860
 Call Trace:
  iwl_pcie_rx_handle+0x220/0x880
  iwl_pcie_irq_handler+0x6c9/0xa20
  ? irq_forced_thread_fn+0x60/0x60
  ? irq_thread_dtor+0x90/0x90

The relevant code that spits the WARNING is:

        case TX_STATUS_FAIL_DEST_PS:
                /* the FW should have stopped the queue and not
                 * return this status
                 */
                WARN_ON(1);
                info->flags |= IEEE80211_TX_STAT_TX_FILTERED;

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=199967.

Fixes: 9fef6544 ("mac80211: always update the PM state of a peer on MGMT / DATA frames")
Cc: <stable@vger.kernel.org>   #4.16+
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Make wmm_rule be part of the reg_rule structure. This simplifies the
code a lot at the cost of having bigger memory usage. However in most
cases we have only few reg_rule's and when we do have many like in
iwlwifi we do not save memory as it allocates a separate wmm_rule for
each channel anyway.

This also fixes a bug reported in various places where somewhere the
pointers were corrupted and we ended up doing a null-dereference.

Fixes: 230ebaa1 ("cfg80211: read wmm rules from regulatory database")
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
[rephrase commit message slightly]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The mac80211_hwsim driver intends to say that it supports up to four
STBC receive streams, but instead it ends up saying something undefined.
The IEEE80211_VHT_CAP_RXSTBC_X macros aren't independent bits that can
be ORed together, but values.  In this case, _4 is the appropriate one
to use.
Signed-off-by: Danek Duvall <duvall@comfychair.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The mod mask for VHT capabilities intends to say that you can override
the number of STBC receive streams, and it does, but only by accident.
The IEEE80211_VHT_CAP_RXSTBC_X aren't bits to be set, but values (albeit
left-shifted).  ORing the bits together gets the right answer, but we
should use the _MASK macro here instead.
Signed-off-by: Danek Duvall <duvall@comfychair.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Pointer arithmetic already adjusts by the size of the struct,
so the sizeof() calculation is wrong. This is basically the
same as Colin King's patch for similar code in the iwlwifi
driver.

Fixes: 230ebaa1 ("cfg80211: read wmm rules from regulatory database")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Syzbot continues to try to create mac80211_hwsim radios, and
manages to pass parameters that are later checked with WARN_ON
in cfg80211 - catch another one in hwsim directly.

Reported-by: syzbot+2a12f11c306afe871c1f@syzkaller.appspotmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

The TXQ teardown code can reference the vif data structures that are
stored in the netdev private memory area if there are still packets on
the queue when it is being freed. Since the TXQ teardown code is run
after the netdevs are freed, this can lead to a use-after-free. Fix this
by moving the TXQ teardown code to earlier in ieee80211_unregister_hw().
Reported-by: Ben Greear <greearb@candelatech.com>
Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

One more driver is apparently broken by the recent change
to linux/platform_device.h:

net/rfkill/rfkill-gpio.c: In function 'rfkill_gpio_acpi_probe':
net/rfkill/rfkill-gpio.c:82:29: error: dereferencing pointer to incomplete type 'const struct acpi_device_id'

Include linux/mod_devicetable.h to get the definition of the
acpi_device_id structure.

Fixes: ac316725 ("headers: separate linux/mod_devicetable.h from linux/platform_device.h")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Pull networking fixes from David Miller:
 "Last bit of straggler fixes...

  1) Fix btf library licensing to LGPL, from Martin KaFai lau.

  2) Fix error handling in bpf sockmap code, from Daniel Borkmann.

  3) XDP cpumap teardown handling wrt. execution contexts, from Jesper
     Dangaard Brouer.

  4) Fix loss of runtime PM on failed vlan add/del, from Ivan
     Khoronzhuk.

  5) xen-netfront caches skb_shinfo(skb) across a __pskb_pull_tail()
     call, which potentially changes the skb's data buffer, and thus
     skb_shinfo(). Fix from Juergen Gross"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  xen/netfront: don't cache skb_shinfo()
  net: ethernet: ti: cpsw: fix runtime_pm while add/kill vlan
  net: ethernet: ti: cpsw: clear all entries when delete vid
  xdp: fix bug in devmap teardown code path
  samples/bpf: xdp_redirect_cpu adjustment to reproduce teardown race easier
  xdp: fix bug in cpumap teardown code path
  bpf, sockmap: fix cork timeout for select due to epipe
  bpf, sockmap: fix leak in bpf_tcp_sendmsg wait for mem path
  bpf, sockmap: fix bpf_tcp_sendmsg sock error handling
  bpf: btf: Change tools/lib/bpf/btf to LGPL

skb_shinfo() can change when calling __pskb_pull_tail(): Don't cache
its return value.

Cc: stable@vger.kernel.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Grygorii Strashko says:

====================
net: ethernet: ti: cpsw: fix runtime pm while add/del reserved vid

Here 2 not critical fixes for:
- vlan ale table leak while error if deleting vlan (simplifies next fix)
- runtime pm while try to set reserved vlan
====================
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

It's exclusive with normal behaviour but if try to set vlan to one of
the reserved values is made, the cpsw runtime pm is broken.

Fixes: a6c5d14f ("drivers: net: cpsw: ndev: fix accessing to suspended device")
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

In cases if some of the entries were not found in forwarding table
while killing vlan, the rest not needed entries still left in the
table. No need to stop, as entry was deleted anyway. So fix this by
returning error only after all was cleaned. To implement this, return
-ENOENT in cpsw_ale_del_mcast() as it's supposed to be.
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

If zram supports writeback feature, it's no longer a
BD_CAP_SYNCHRONOUS_IO device beause zram does asynchronous IO operations
for incompressible pages.

Do not pretend to be synchronous IO device.  It makes the system very
sluggish due to waiting for IO completion from upper layers.

Furthermore, it causes a user-after-free problem because swap thinks the
opearion is done when the IO functions returns so it can free the page
(e.g., lock_page_or_retry and goto out_release in do_swap_page) but in
fact, IO is asynchronous so the driver could access a just freed page
afterward.

This patch fixes the problem.

  BUG: Bad page state in process qemu-system-x86  pfn:3dfab21
  page:ffffdfb137eac840 count:0 mapcount:0 mapping:0000000000000000 index:0x1
  flags: 0x17fffc000000008(uptodate)
  raw: 017fffc000000008 dead000000000100 dead000000000200 0000000000000000
  raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000
  page dumped because: PAGE_FLAGS_CHECK_AT_PREP flag set
  bad because of flags: 0x8(uptodate)
  CPU: 4 PID: 1039 Comm: qemu-system-x86 Tainted: G    B 4.18.0-rc5+ #1
  Hardware name: Supermicro Super Server/X10SRL-F, BIOS 2.0b 05/02/2017
  Call Trace:
    dump_stack+0x5c/0x7b
    bad_page+0xba/0x120
    get_page_from_freelist+0x1016/0x1250
    __alloc_pages_nodemask+0xfa/0x250
    alloc_pages_vma+0x7c/0x1c0
    do_swap_page+0x347/0x920
    __handle_mm_fault+0x7b4/0x1110
    handle_mm_fault+0xfc/0x1f0
    __get_user_pages+0x12f/0x690
    get_user_pages_unlocked+0x148/0x1f0
    __gfn_to_pfn_memslot+0xff/0x3c0 [kvm]
    try_async_pf+0x87/0x230 [kvm]
    tdp_page_fault+0x132/0x290 [kvm]
    kvm_mmu_page_fault+0x74/0x570 [kvm]
    kvm_arch_vcpu_ioctl_run+0x9b3/0x1990 [kvm]
    kvm_vcpu_ioctl+0x388/0x5d0 [kvm]
    do_vfs_ioctl+0xa2/0x630
    ksys_ioctl+0x70/0x80
    __x64_sys_ioctl+0x16/0x20
    do_syscall_64+0x55/0x100
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

Link: https://lore.kernel.org/lkml/0516ae2d-b0fd-92c5-aa92-112ba7bd32fc@contabo.de/
Link: http://lkml.kernel.org/r/20180802051112.86174-1-minchan@kernel.org
[minchan@kernel.org: fix changelog, add comment]
 Link: https://lore.kernel.org/lkml/0516ae2d-b0fd-92c5-aa92-112ba7bd32fc@contabo.de/
 Link: http://lkml.kernel.org/r/20180802051112.86174-1-minchan@kernel.org
 Link: http://lkml.kernel.org/r/20180805233722.217347-1-minchan@kernel.org
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Tino Lehnig <tino.lehnig@contabo.de>
Tested-by: Tino Lehnig <tino.lehnig@contabo.de>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: <stable@vger.kernel.org>	[4.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ioremap_prot() can return NULL which could lead to an oops.

Link: http://lkml.kernel.org/r/1533195441-58594-1-git-send-email-chenjie6@huawei.comSigned-off-by: chen jie <chenjie6@huawei.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: chenjie <chenjie6@huawei.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

With gcc-8 fsanitize=null become very noisy.  GCC started to complain
about things like &a->b, where 'a' is NULL pointer.  There is no NULL
dereference, we just calculate address to struct member.  It's
technically undefined behavior so UBSAN is correct to report it.  But as
long as there is no real NULL-dereference, I think, we should be fine.

-fno-delete-null-pointer-checks compiler flag should protect us from any
consequences.  So let's just no use -fsanitize=null as it's not useful
for us.  If there is a real NULL-deref we will see crash.  Even if
userspace mapped something at NULL (root can do this), with things like
SMAP should catch the issue.

Link: http://lkml.kernel.org/r/20180802153209.813-1-aryabinin@virtuozzo.comSigned-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This entry was created with my personal e-mail address.  Update this entry
to my open-source kernel.org account.

Link: http://lkml.kernel.org/r/20180806143904.4716-4-kieran.bingham@ideasonboard.comSigned-off-by: Kieran Bingham <kbingham@kernel.org>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull i2c fix from Wolfram Sang:
 "A single driver bugfix for I2C.

  The bug was found by systematically stress testing the driver, so I am
  confident to merge it that late in the cycle although it is probably
  unusually large"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: xlp9xx: Fix case where SSIF read transaction completes early

Daniel Borkmann says:

====================
pull-request: bpf 2018-08-10

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

The main changes are:

1) Fix cpumap and devmap on teardown as they're under RCU context
   and won't have same assumption as running under NAPI protection,
   from Jesper.

2) Fix various sockmap bugs in bpf_tcp_sendmsg() code, e.g. we had
   a bug where socket error was not propagated correctly, from Daniel.

3) Fix incompatible libbpf header license for BTF code and match it
   before it gets officially released with the rest of libbpf which
   is LGPL-2.1, from Martin.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Jesper Dangaard Brouer says:

====================
Removing entries from cpumap and devmap, goes through a number of
syncronization steps to make sure no new xdp_frames can be enqueued.
But there is a small chance, that xdp_frames remains which have not
been flushed/processed yet.  Flushing these during teardown, happens
from RCU context and not as usual under RX NAPI context.

The optimization introduced in commt 389ab7f0 ("xdp: introduce
xdp_return_frame_rx_napi"), missed that the flush operation can also
be called from RCU context.  Thus, we cannot always use the
xdp_return_frame_rx_napi call, which take advantage of the protection
provided by XDP RX running under NAPI protection.

The samples/bpf xdp_redirect_cpu have a --stress-mode, that is
adjusted to easier reproduce (verified by Red Hat QA).
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Like cpumap teardown, the devmap teardown code also flush remaining
xdp_frames, via bq_xmit_all() in case map entry is removed.  The code
can call xdp_return_frame_rx_napi, from the the wrong context, in-case
ndo_xdp_xmit() fails.

Fixes: 389ab7f0 ("xdp: introduce xdp_return_frame_rx_napi")
Fixes: 735fc405 ("xdp: change ndo_xdp_xmit API to support bulking")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

The teardown race in cpumap is really hard to reproduce.  These changes
makes it easier to reproduce, for QA.

The --stress-mode now have a case of a very small queue size of 8, that helps
to trigger teardown flush to encounter a full queue, which results in calling
xdp_return_frame API, in a non-NAPI protect context.

Also increase MAX_CPUS, as my QA department have larger machines than me.
Tested-by: Jean-Tsung Hsiao <jhsiao@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

When removing a cpumap entry, a number of syncronization steps happen.
Eventually the teardown code __cpu_map_entry_free is invoked from/via
call_rcu.

The teardown code __cpu_map_entry_free() flushes remaining xdp_frames,
by invoking bq_flush_to_queue, which calls xdp_return_frame_rx_napi().
The issues is that the teardown code is not running in the RX NAPI
code path.  Thus, it is not allowed to invoke the NAPI variant of
xdp_return_frame.

This bug was found and triggered by using the --stress-mode option to
the samples/bpf program xdp_redirect_cpu.  It is hard to trigger,
because the ptr_ring have to be full and cpumap bulk queue max
contains 8 packets, and a remote CPU is racing to empty the ptr_ring
queue.

Fixes: 389ab7f0 ("xdp: introduce xdp_return_frame_rx_napi")
Tested-by: Jean-Tsung Hsiao <jhsiao@redhat.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

Pull crypto fix from Herbert Xu:
 "This fixes a performance regression in arm64 NEON crypto as well as a
  crash in x86 aegis/morus on unsupported CPUs"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: x86/aegis,morus - Fix and simplify CPUID checks
  crypto: arm64 - revert NEON yield for fast AEAD implementations

Pull networking fixes from David Miller:

 1) The real fix for the ipv6 route metric leak Sabrina was seeing, from
    Cong Wang.

 2) Fix syzbot triggers AF_PACKET v3 ring buffer insufficient room
    conditions, from Willem de Bruijn.

 3) vsock can reinitialize active work struct, fix from Cong Wang.

 4) RXRPC keepalive generator can wedge a cpu, fix from David Howells.

 5) Fix locking in AF_SMC ioctl, from Ursula Braun.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  dsa: slave: eee: Allow ports to use phylink
  net/smc: move sock lock in smc_ioctl()
  net/smc: allow sysctl rmem and wmem defaults for servers
  net/smc: no shutdown in state SMC_LISTEN
  net: aquantia: Fix IFF_ALLMULTI flag functionality
  rxrpc: Fix the keepalive generator [ver #2]
  net/mlx5e: Cleanup of dcbnl related fields
  net/mlx5e: Properly check if hairpin is possible between two functions
  vhost: reset metadata cache when initializing new IOTLB
  llc: use refcount_inc_not_zero() for llc_sap_find()
  dccp: fix undefined behavior with 'cwnd' shift in ccid2_cwnd_restart()
  tipc: fix an interrupt unsafe locking scenario
  vsock: split dwork to avoid reinitializations
  net: thunderx: check for failed allocation lmac->dmacs
  cxgb4: mk_act_open_req() buggers ->{local, peer}_ip on big-endian hosts
  packet: refine ring v3 block size test to hold one frame
  ip6_tunnel: use the right value for ipv4 min mtu check in ip6_tnl_xmit
  ipv6: fix double refcount of fib6_metrics

During ipmi stress tests we see occasional failure of transactions
at the boot time. This happens in the case of a I2C_M_RECV_LEN
transactions, when the read transfer completes (with the initial
read length of 34) before the driver gets a chance to handle interrupts.

The current driver code expects at least 2 interrupts for I2C_M_RECV_LEN
transactions. The length is updated during the first interrupt, and  the
buffer contents are only copied during subsequent interrupts. In case of
just one interrupt, we will complete the transaction without copying
out the bytes from RX fifo.

Update the code to drain the RX fifo after the length update,
so that the transaction completes correctly in all cases.
Signed-off-by: George Cherian <george.cherian@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org