'err' is overwrited to 0 after maybe_pull_tail() call, so the error
code was not set if skb_partial_csum_set() call failed. Fix to return
error -EPROTO from those error handling case instead of 0.

Fixes: d52eb0d4 ('xen-netback: make sure skb linear area covers checksum field')
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: NWei Liu <wei.liu2@citrix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jakub reported while working with nlmon netlink sniffer that parts of
the inet_diag_sockid are not initialized when r->idiag_family != AF_INET6.
That is, fields of r->id.idiag_src[1 ... 3], r->id.idiag_dst[1 ... 3].

In fact, it seems that we can leak 6 * sizeof(u32) byte of kernel [slab]
memory through this. At least, in udp_dump_one(), we allocate a skb in ...

  rep = nlmsg_new(sizeof(struct inet_diag_msg) + ..., GFP_KERNEL);

... and then pass that to inet_sk_diag_fill() that puts the whole struct
inet_diag_msg into the skb, where we only fill out r->id.idiag_src[0],
r->id.idiag_dst[0] and leave the rest untouched:

  r->id.idiag_src[0] = inet->inet_rcv_saddr;
  r->id.idiag_dst[0] = inet->inet_daddr;

struct inet_diag_msg embeds struct inet_diag_sockid that is correctly /
fully filled out in IPv6 case, but for IPv4 not.

So just zero them out by using plain memset (for this little amount of
bytes it's probably not worth the extra check for idiag_family == AF_INET).

Similarly, fix also other places where we fill that out.
Reported-by: NJakub Zawadzki <darkjames-ws@darkjames.pl>
Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While testing my changes for TSO support in SIT devices,
I was using sit0 tunnel which appears to include nopmtudisc flag.

But using :

ip tun add sittun mode sit remote $REMOTE_IPV4 local $LOCAL_IPV4 \
   dev $IFACE

We get a tunnel which rejects too long packets because of the mtu check
which is not yet GSO aware.

erd:~# ip tunnel
sittun: ipv6/ip  remote 10.246.17.84  local 10.246.17.83  ttl inherit  6rd-prefix 2002::/16
sit0: ipv6/ip  remote any  local any  ttl 64  nopmtudisc 6rd-prefix 2002::/16

This patch is based on an excellent report from
Michal Shmidt.

In the future, we probably want to extend the MTU check to do the
right thing for GSO packets...

Fixes: ("61c1db7f ipv6: sit: add GSO/TSO support")
Reported-by: NMichal Schmidt <mschmidt@redhat.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Tested-by: NMichal Schmidt <mschmidt@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sockets marked with IPV6_PMTUDISC_PROBE (or later IPV6_PMTUDISC_INTERFACE)
don't respect this setting when the outgoing interface supports UFO.

We had the same problem in IPv4, which was fixed in commit
daba287b ("ipv4: fix DO and PROBE pmtu
mode regarding local fragmentation with UFO/CORK").

Also IPV6_DONTFRAG mode did not care about already corked data, thus
it may generate a fragmented frame even if this socket option was
specified. It also did not care about the length of the ipv6 header and
possible options.

In the error path allow the user to receive the pmtu notifications via
both, rxpmtu method or error queue. The user may opted in for both,
so deliver the notification to both error handlers (the handlers check
if the error needs to be enqueued).

Also report back consistent pmtu values when sending on an already
cork-appended socket.
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Certain dm962x revisions contain an bug, where if a USB bulk transfer retry
(E.G. if bulk crc mismatch) happens right after a transfer with odd or
maxpacket length, the internal tx hardware fifo gets out of sync causing
the interface to stop working.

Work around it by adding up to 3 bytes of padding to ensure this situation
cannot trigger.

This workaround also means we never pass multiple-of-maxpacket size skb's
to usbnet, so the length adjustment to handle usbnet's padding of those can
be removed.

Cc: <stable@vger.kernel.org>
Reported-by: NJoseph Chang <joseph_chang@davicom.com.tw>
Signed-off-by: NPeter Korsgaard <peter@korsgaard.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver nowadays also support dm9620/dm9621a based USB 2.0 ethernet
adapters, so adjust module/driver description and Kconfig help text to
match.
Signed-off-by: NPeter Korsgaard <peter@korsgaard.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

dm9620/dm9621a require room for 4 byte padding even in dm9601 (3 byte
header) mode.

Cc: <stable@vger.kernel.org>
Signed-off-by: NPeter Korsgaard <peter@korsgaard.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

dm9621a is functionally identical to dm9620, so the existing handling can
directly be used.

Thanks to Davicom for sending me a dongle.
Signed-off-by: NPeter Korsgaard <peter@korsgaard.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ipgre_header_parse() needs to parse the tunnel's ip header and it
uses mac_header to locate the iphdr. This got broken when gre tunneling
was refactored as mac_header is no longer updated to point to iphdr.
Introduce skb_pop_mac_header() helper to do the mac_header assignment
and use it in ipgre_rcv() to fix msg_name parsing.

Bug introduced in commit c5441932 (GRE: Refactor GRE tunneling code.)

Cc: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: NTimo Teräs <timo.teras@iki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds support for enabling In Band mode in 10 mbps speed.
RGMII supports 1 Gig and 100 mbps mode for Forced mode of operation.
For 10mbps mode it should be configured to in band mode so that link
status, duplexity and speed are determined from the RGMII input data
stream
Signed-off-by: NMugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Ding Tianhong says:

====================
Jay Vosburgh said that the bond_3ad_adapter_speed_changed and
bond_3ad_adapter_duplex_changed is called with RTNL only, and
the functions will modify the port's information with no further
locking, they will not mutex against bond state machine and
incoming LACPDU which do not hold RTNL, So I add port lock to
protect the port information.

But they are not critical bugs, they exist since day one, and till
now they have never been hit and reported, because change for speed
and duplex is very rare, and will not occur critical problem.

The comments in the function is very old, cleanup the comments together.
====================
Signed-off-by: NJay Vosburgh <fubar@us.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The bond_3ad_handle_link_change is called with RTNL only,
and the function will modify the port's information with
no further locking, it will not mutex against bond state
machine and incoming LACPDU which do not hold RTNL, So I
add __get_state_machine_lock to protect the port.

But it is not a critical bug, it exist since day one, and till
now it has never been hit and reported, because changes to
speed is very rare, and will not occur critical problem.

The comments in the function is very old, cleanup it and
add a new pr_debug to debug the port message.
Signed-off-by: NDing Tianhong <dingtianhong@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jay Vosburgh said that the bond_3ad_adapter_duplex_changed is
called with RTNL only, and the function will modify the port's
information with no further locking, it will not mutex against
bond state machine and incoming LACPDU which do not hold RTNL,
So I add __get_state_machine_lock to protect the port.

But it is not a critical bug, it exist since day one, and till
now it has never been hit and reported, because changes to
speed is very rare, and will not occur critical problem.

The comments in the function is very old, cleanup it.
Suggested-by: NJay Vosburgh <fubar@us.ibm.com>
Signed-off-by: NDing Tianhong <dingtianhong@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Jay Vosburgh said that the bond_3ad_adapter_speed_changed is
called with RTNL only, and the function will modify the port's
information with no further locking, it will not mutex against
bond state machine and incoming LACPDU which do not hold RTNL,
So I add __get_state_machine_lock to protect the port.

But it is not a critical bug, it exist since day one, and till
now it has never been hit and reported, because changes to
speed is very rare, and will not occur critical problem.

The comment in the function is very old, cleanup it.
Suggested-by: NJay Vosburgh <fubar@us.ibm.com>
Signed-off-by: NDing Tianhong <dingtianhong@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull drm fixes from Dave Airlie:
 "Definitely seems quieter this week,

  Radeon, intel, intel broadwell, vmwgfx, ttm, armada, and a couple of
  core fixes, one revert in radeon

  Most of these are either going to stable or fixes for things
  introduced in the merge window"

* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (30 commits)
  drm/edid: add quirk for BPC in Samsung NP700G7A-S01PL notebook
  drm/ttm: Fix accesses through vmas with only partial coverage
  drm/nouveau: only runtime suspend by default in optimus configuration
  drm: don't double-free on driver load error
  Revert "drm/radeon: Implement radeon_pci_shutdown"
  drm/radeon: add missing display tiling setup for oland
  drm/radeon: fix typo in cik_copy_dma
  drm/radeon/cik: plug in missing blit callback
  drm/radeon/dpm: Fix hwmon crash
  drm/radeon: Fix sideport problems on certain RS690 boards
  drm/i915: don't update the dri1 breadcrumb with modesetting
  DRM: Armada: prime refcounting bug fix
  DRM: Armada: fix printing of phys_addr_t/dma_addr_t
  DRM: Armada: destroy framebuffer after helper
  DRM: Armada: implement lastclose() for fbhelper
  drm/i915: Repeat eviction search after idling the GPU
  drm/vmwgfx: Add max surface memory param
  drm/i915: Fix use-after-free in do_switch
  drm/i915: fix pm init ordering
  drm/i915: Hold mutex across i915_gem_release
  ...

Pull networking fixes from David Miller:
 "A quick batch of fixes, including the annoying bad lock stack problem
  introduced by udp_sk_rx_dst_set() locking change:

   1) Use xchg() instead of sk_dst_lock() in udp_sk_rx_dst_set(), from
      Eric Dumazet.

   2) qlcnic bug fixes from Himanshu Madhani and Manish Chopra.

   3) Update IPSEC MAINTAINERS entry, from Steffen Klassert.

   4) Administrative neigh entry changes should generate netlink
      notifications the same as event generated ones.  From Bob
      Gilligan.

   5) Netfilter SYNPROXY fixes from Patrick McHardy.

   6) Netfilter nft_reject endianness fixes from Eric Leblond"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  qlcnic: Dump mailbox registers when mailbox command times out.
  qlcnic: Fix mailbox processing during diagnostic test
  qlcnic: Allow firmware dump collection when auto firmware recovery is disabled
  qlcnic: Fix memory allocation
  qlcnic: Fix TSS/RSS validation for 83xx/84xx series adapter.
  qlcnic: Fix TSS/RSS ring validation logic.
  qlcnic: Fix diagnostic test for all adapters.
  qlcnic: Fix usage of netif_tx_{wake, stop} api during link change.
  xen-netback: fix fragments error handling in checksum_setup_ip()
  neigh: Netlink notification for administrative NUD state change
  ipv4: improve documentation of ip_no_pmtu_disc
  net: unix: allow bind to fail on mutex lock
  MAINTAINERS: Update the IPsec maintainer entry
  udp: ipv4: do not use sk_dst_lock from softirq context
  netvsc: don't flush peers notifying work during setting mtu
  can: peak_usb: fix mem leak in pcan_usb_pro_init()
  can: ems_usb: fix urb leaks on failure paths
  sctp: loading sctp when load sctp_probe
  netfilter: nft_reject: fix endianness in dump function
  netfilter: SYNPROXY target: restrict to INPUT/FORWARD

Marc Kleine-Budde says:

====================
this is a pull request with two fixes for net/master, the current release
cycle.

It consists of a patch by Alexey Khoroshilov from the Linux Driver Verification
project, which fixes a memory leak in ems_usb's failure patch. And a patch by
me which fixes a memory leak in the peak usb driver.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Himanshu Madhani says:

====================
qlcnic: Bug fixes.

This series contains bug fixes for mailbox handling and multi Tx queue support
for all supported adapters.

changes from v1 -> v2
o updated patch to fix usage of netif_tx_{wake,stop} api during link change
  as per David Miller's suggestion.
o Dropped patch to use spinklock per tx queue for more work.
o Added reworked patch for memory allocation failures.
o Added patch to allow capturing of dump, when auto recovery is disabled in firmware.
o Added patches for mailbox interrupt handling and debugging data for mailbox failure.

Please apply to net.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NManish Chopra <manish.chopra@qlogic.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

o Do not enable mailbox polling in case of legacy interrupt.
  Process mailbox AEN/response from the interrupt.
Signed-off-by: NManish Chopra <manish.chopra@qlogic.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

o Allow driver to collect firmware dump, during a forced firmware dump
  operation, when auto firmware recovery is disabled. Also, during this
  operation, driver should not allow reset recovery to be performed.
Signed-off-by: NManish Chopra <manish.chopra@qlogic.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

o Use vzalloc() instead of kzalloc() for allocation of
  bootloader size memory. kzalloc() may fail to allocate
  the size of bootloader
Signed-off-by: NManish Chopra <manish.chopra@qlogic.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

o Current code was not allowing the user to configure more
  than one Tx ring using ethtool for 83xx/84xx adapter.
  This regression was introduced by commit id
  18afc102 ("qlcnic: Enable
  multiple Tx queue support for 83xx/84xx Series adapter.")
Signed-off-by: NHimanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

o TSS/RSS ring validation does not take into account that either
  of these ring values can be 0. This patch fixes this validation
  and would fail set_channel operation if any of these ring value
  is 0. This regression was added as part of commit id
  34e8c406 ("qlcnic: refactor Tx/SDS
  ring calculation and validation in driver.")
Signed-off-by: NHimanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

o Driver should re-allocate all Tx queues after completing
  diagnostic tests. This regression was added by commit id
  c2c5e3a0 ("qlcnic: Enable
  diagnostic test for multiple Tx queues.")
Signed-off-by: NHimanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

o Driver was using netif_tx_{stop,wake}_all_queues() api
  during link change event. Remove these api calls to
  manage queue start/stop event, as core networking stack
  will manage this based on netif_carrier_{on,off} call.
  These API's were modified as part of commit id
  012ec812 ("qlcnic: Multi Tx
  queue support for 82xx Series adapter.")
Signed-off-by: NShahed Shaikh <shahed.shaikh@qlogic.com>
Signed-off-by: NHimanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix to return -EPROTO error if fragments detected in checksum_setup_ip().

Fixes: 1431fb31 ('xen-netback: fix fragment detection in checksum setup')
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Reviewed-by: NPaul Durrant <paul.durrant@citrix.com>
Acked-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The neighbour code sends up an RTM_NEWNEIGH netlink notification if
the NUD state of a neighbour cache entry is changed by a timer (e.g.
from REACHABLE to STALE), even if the lladdr of the entry has not
changed.

But an administrative change to the the NUD state of a neighbour cache
entry that does not change the lladdr (e.g. via "ip -4 neigh change
...  nud ...") does not trigger a netlink notification.  This means
that netlink listeners will not hear about administrative NUD state
changes such as from a resolved state to PERMANENT.

This patch changes the neighbor code to generate an RTM_NEWNEIGH
message when the NUD state of an entry is changed administratively.
Signed-off-by: NBob Gilligan <gilligan@aristanetworks.com>
Acked-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull regulator/clk fix from Mark Brown:
 "Fix s2mps11 build

  This patch fixes a build failure that appeared in v3.13-rc4 due to an
  RTC/MFD update merged via -mm"

* tag 's2mps11-build' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  mfd: s2mps11: Fix build after regmap field rename in sec-core.c

Pull timer fixes from Ingo Molnar:
 "Five self-contained fixlets:

   - fix clocksource driver build bug
   - fix two sched_clock() bugs triggering on specific hardware
   - fix devicetree enumeration bug affecting specific hardware
   - fix irq handler registration race resulting in boot crash
   - fix device node refcount bug"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: dw_apb_timer_of: Fix support for dts binding "snps,dw-apb-timer"
  clocksource: dw_apb_timer_of: Fix read_sched_clock
  clocksource: sunxi: Stop timer from ticking before enabling interrupts
  clocksource: clksrc-of: Do not drop unheld reference on device node
  clocksource: armada-370-xp: Register sched_clock after the counter reset
  clocksource: time-efm32: Select CLKSRC_MMIO

Pull scheduler fixes from Ingo Molnar:
 "Three fixes for scheduler crashes, each triggers in relatively rare,
  hardware environment dependent situations"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Rework sched_fair time accounting
  math64: Add mul_u64_u32_shr()
  sched: Remove PREEMPT_NEED_RESCHED from generic code
  sched: Initialize power_orig for overlapping groups

Pull perf fix from Ingo Molnar:
 "An x86/intel event constraint fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86: Fix constraint table end marker bug

Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pablo Neira Ayuso says:

====================
The following patchset contains two Netfilter fixes for your net
tree, they are:

* Fix endianness in nft_reject, the NFTA_REJECT_TYPE netlink attributes
  was not converted to network byte order as needed by all nfnetlink
  subsystems, from Eric Leblond.

* Restrict SYNPROXY target to INPUT and FORWARD chains, this avoid a
  possible crash due to misconfigurations, from Patrick McHardy.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is similar to the set_peek_off patch where calling bind while the
socket is stuck in unix_dgram_recvmsg() will block and cause a hung task
spew after a while.

This is also the last place that did a straightforward mutex_lock(), so
there shouldn't be any more of these patches.
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add the IPsec git trees and some pure IPsec modules
to the IPsec section in the MAINTAINERS file.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Using sk_dst_lock from softirq context is not supported right now.

Instead of adding BH protection everywhere,
udp_sk_rx_dst_set() can instead use xchg(), as suggested
by David.
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Fixes: 97502231 ("udp: ipv4: must add synchronization in udp_sk_rx_dst_set()")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull GPIO fixes from Linus Walleij:
 "All but one are long-standing bug fixes that are also tagged for
  stable

   - Driver bug fixes for SH PFC, TWL4030, MSM and RCAR.

   - Update the MAINTAINERS"

* tag 'gpio-v3.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: rcar: Fix level interrupt handling
  gpio: msm: Fix irq mask/unmask by writing bits instead of numbers
  gpio: twl4030: Fix regression for twl gpio LED output
  sh-pfc: Fix PINMUX_GPIO macro
  MAINTAINERS: update GPIO maintainers entry

Pull two Ceph fixes from Sage Weil:
 "One of these is fixing a regression from the d_flags file type patch
  that went into -rc1 that broke instantiation of inodes and dentries
  (we were doing dentries first).  The other is just an off-by-one
  corner case"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  ceph: Avoid data inconsistency due to d-cache aliasing in readpage()
  ceph: initialize inode before instantiating dentry

There's a possible deadlock if we flush the peers notifying work during setting
mtu:

[   22.991149] ======================================================
[   22.991173] [ INFO: possible circular locking dependency detected ]
[   22.991198] 3.10.0-54.0.1.el7.x86_64.debug #1 Not tainted
[   22.991219] -------------------------------------------------------
[   22.991243] ip/974 is trying to acquire lock:
[   22.991261]  ((&(&net_device_ctx->dwork)->work)){+.+.+.}, at: [<ffffffff8108af95>] flush_work+0x5/0x2e0
[   22.991307]
but task is already holding lock:
[   22.991330]  (rtnl_mutex){+.+.+.}, at: [<ffffffff81539deb>] rtnetlink_rcv+0x1b/0x40
[   22.991367]
which lock already depends on the new lock.

[   22.991398]
the existing dependency chain (in reverse order) is:
[   22.991426]
-> #1 (rtnl_mutex){+.+.+.}:
[   22.991449]        [<ffffffff810dfdd9>] __lock_acquire+0xb19/0x1260
[   22.991477]        [<ffffffff810e0d12>] lock_acquire+0xa2/0x1f0
[   22.991501]        [<ffffffff81673659>] mutex_lock_nested+0x89/0x4f0
[   22.991529]        [<ffffffff815392b7>] rtnl_lock+0x17/0x20
[   22.991552]        [<ffffffff815230b2>] netdev_notify_peers+0x12/0x30
[   22.991579]        [<ffffffffa0340212>] netvsc_send_garp+0x22/0x30 [hv_netvsc]
[   22.991610]        [<ffffffff8108d251>] process_one_work+0x211/0x6e0
[   22.991637]        [<ffffffff8108d83b>] worker_thread+0x11b/0x3a0
[   22.991663]        [<ffffffff81095e5d>] kthread+0xed/0x100
[   22.991686]        [<ffffffff81681c6c>] ret_from_fork+0x7c/0xb0
[   22.991715]
-> #0 ((&(&net_device_ctx->dwork)->work)){+.+.+.}:
[   22.991715]        [<ffffffff810de817>] check_prevs_add+0x967/0x970
[   22.991715]        [<ffffffff810dfdd9>] __lock_acquire+0xb19/0x1260
[   22.991715]        [<ffffffff810e0d12>] lock_acquire+0xa2/0x1f0
[   22.991715]        [<ffffffff8108afde>] flush_work+0x4e/0x2e0
[   22.991715]        [<ffffffff8108e1b5>] __cancel_work_timer+0x95/0x130
[   22.991715]        [<ffffffff8108e303>] cancel_delayed_work_sync+0x13/0x20
[   22.991715]        [<ffffffffa03404e4>] netvsc_change_mtu+0x84/0x200 [hv_netvsc]
[   22.991715]        [<ffffffff815233d4>] dev_set_mtu+0x34/0x80
[   22.991715]        [<ffffffff8153bc2a>] do_setlink+0x23a/0xa00
[   22.991715]        [<ffffffff8153d054>] rtnl_newlink+0x394/0x5e0
[   22.991715]        [<ffffffff81539eac>] rtnetlink_rcv_msg+0x9c/0x260
[   22.991715]        [<ffffffff8155cdd9>] netlink_rcv_skb+0xa9/0xc0
[   22.991715]        [<ffffffff81539dfa>] rtnetlink_rcv+0x2a/0x40
[   22.991715]        [<ffffffff8155c41d>] netlink_unicast+0xdd/0x190
[   22.991715]        [<ffffffff8155c807>] netlink_sendmsg+0x337/0x750
[   22.991715]        [<ffffffff8150d219>] sock_sendmsg+0x99/0xd0
[   22.991715]        [<ffffffff8150d63e>] ___sys_sendmsg+0x39e/0x3b0
[   22.991715]        [<ffffffff8150eba2>] __sys_sendmsg+0x42/0x80
[   22.991715]        [<ffffffff8150ebf2>] SyS_sendmsg+0x12/0x20
[   22.991715]        [<ffffffff81681d19>] system_call_fastpath+0x16/0x1b

This is because we hold the rtnl_lock() before ndo_change_mtu() and try to flush
the work in netvsc_change_mtu(), in the mean time, netdev_notify_peers() may be
called from worker and also trying to hold the rtnl_lock. This will lead the
flush won't succeed forever. Solve this by not canceling and flushing the work,
this is safe because the transmission done by NETDEV_NOTIFY_PEERS was
synchronized with the netif_tx_disable() called by netvsc_change_mtu().
Reported-by: NYaju Cao <yacao@redhat.com>
Tested-by: NYaju Cao <yacao@redhat.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Acked-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>