KASAN revealed another access after delete in group.c. This time
it found that we read the header of a received message after the
buffer has been released.
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

v2:
 * Replace busy wait with wait_event()/wake_up_all()
 * Cannot garantee that at the time xennet_remove is called, the
   xen_netback state will not be XenbusStateClosed, so added a
   condition for that
 * There's a small chance for the xen_netback state is
   XenbusStateUnknown by the time the xen_netfront switches to Closed,
   so added a condition for that.

When unloading module xen_netfront from guest, dmesg would output
warning messages like below:

  [  105.236836] xen:grant_table: WARNING: g.e. 0x903 still in use!
  [  105.236839] deferring g.e. 0x903 (pfn 0x35805)

This problem relies on netfront and netback being out of sync. By the time
netfront revokes the g.e.'s netback didn't have enough time to free all of
them, hence displaying the warnings on dmesg.

The trick here is to make netfront to wait until netback frees all the g.e.'s
and only then continue to cleanup for the module removal, and this is done by
manipulating both device states.
Signed-off-by: NEduardo Otubo <otubo@redhat.com>
Acked-by: NJuergen Gross <jgross@suse.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Merge tag 'mac80211-for-davem-2017-11-27' of git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211

Johannes Berg says:

====================
Four fixes:
 * CRYPTO_SHA256 is needed for regdb validation
 * mac80211: mesh path metric was wrong in some frames
 * mac80211: use QoS null-data packets on QoS connections
 * mac80211: tear down RX aggregation sessions first to
   drop fewer packets in HW restart scenarios
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Xin Long says:

====================
sctp: a bunch of fixes for stream reconfig

This patchset is to make stream reset and asoc reset work more correctly
for stream reconfig.

Thank to Marcelo making them very clear.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When doing asoc reset, if the sender of the response has already sent some
chunk and increased asoc->next_tsn before the duplicate request comes, the
response will use the old result with an incorrect sender next_tsn.

Better than asoc->next_tsn, asoc->ctsn_ack_point can't be changed after
the sender of the response has performed the asoc reset and before the
peer has confirmed it, and it's value is still asoc->next_tsn original
value minus 1.

This patch sets sender next_tsn for the old result with ctsn_ack_point
plus 1 when processing the duplicate request, to make sure the sender
next_tsn value peer gets will be always right.

Fixes: 692787ce ("sctp: implement receiver-side procedures for the SSN/TSN Reset Request Parameter")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now when doing asoc reset, it cleans up sacked and abandoned queues
by calling sctp_outq_free where it also cleans up unsent, retransmit
and transmitted queues.

It's safe for the sender of response, as these 3 queues are empty at
that time. But when the receiver of response is doing the reset, the
users may already enqueue some chunks into unsent during the time
waiting the response, and these chunks should not be flushed.

To void the chunks in it would be removed, it moves the queue into a
temp list, then gets it back after sctp_outq_free is done.

The patch also fixes some incorrect comments in
sctp_process_strreset_tsnreq.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As it says in rfc6525#section5.1.4, before sending the request,

   C2:  The sender has either no outstanding TSNs or considers all
        outstanding TSNs abandoned.

Prior to this patch, it tried to consider all outstanding TSNs abandoned
by dropping all chunks in all outqs with sctp_outq_free (even including
sacked, retransmit and transmitted queues) when doing this reset, which
is too aggressive.

To make it work gently, this patch will only allow the asoc reset when
the sender has no outstanding TSNs by checking if unsent, transmitted
and retransmit are all empty with sctp_outq_is_empty before sending
and processing the request.

Fixes: 692787ce ("sctp: implement receiver-side procedures for the SSN/TSN Reset Request Parameter")
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now the out stream reset in sctp stream reconf could be done even if
the stream outq is not empty. It means that users can not be sure
since which msg the new ssn will be used.

To make this more synchronous, it shouldn't allow to do out stream
reset until these chunks in unsent outq all are sent out.

This patch checks the corresponding stream outqs when sending and
processing the request . If any of them has unsent chunks in outq,
it will return -EAGAIN instead or send SCTP_STRRESET_IN_PROGRESS
back to the sender.

Fixes: 7f9d68ac ("sctp: implement sender-side procedures for SSN Reset Request Parameter")
Suggested-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now in stream reconf part there are still some places using magic
number 2 for each stream number length. To make it more readable,
this patch is to replace them with sizeof(__u16).
Reported-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When doing HW restart we tear down aggregations.
Since at this point we are not TX'ing any aggregation, while
the peer is still sending RX aggregation over the air, it will
make sense to tear down the RX aggregations first.
Signed-off-by: NSara Sharon <sara.sharon@intel.com>
Signed-off-by: NLuca Coelho <luciano.coelho@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The previous path metric update from RANN frame has not considered
the own link metric toward the transmitting mesh STA. Fix this.

Reported-by: Michael65535
Signed-off-by: NChun-Yeow Yeoh <yeohchunyeow@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

When connected to a QoS/WMM AP, mac80211 should use a QoS NDP
for probing it, instead of a regular non-QoS one, fix this.

Change all the drivers to *not* allow QoS NDP for now, even
though it looks like most of them should be OK with that.
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

If we want to add a datapath flow, which has more than 500 vxlan outputs'
action, we will get the following error reports:
  openvswitch: netlink: Flow action size 32832 bytes exceeds max
  openvswitch: netlink: Flow action size 32832 bytes exceeds max
  openvswitch: netlink: Actions may not be safe on all matching packets
  ... ...

It seems that we can simply enlarge the MAX_ACTIONS_BUFSIZE to fix it, but
this is not the root cause. For example, for a vxlan output action, we need
about 60 bytes for the nlattr, but after it is converted to the flow
action, it only occupies 24 bytes. This means that we can still support
more than 1000 vxlan output actions for a single datapath flow under the
the current 32k max limitation.

So even if the nla_len(attr) is larger than MAX_ACTIONS_BUFSIZE, we
shouldn't report EINVAL and keep it move on, as the judgement can be
done by the reserve_sfa_size.
Signed-off-by: Nzhangliping <zhangliping02@baidu.com>
Acked-by: NPravin B Shelar <pshelar@ovn.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

gso_type is being used in binary AND operations together with SKB_GSO_UDP.
The issue is that variable gso_type is of type unsigned short and
SKB_GSO_UDP expands to more than 16 bits:

SKB_GSO_UDP = 1 << 16

this makes any binary AND operation between gso_type and SKB_GSO_UDP to
be always zero, hence making some code unreachable and likely causing
undesired behavior.

Fix this by changing the data type of variable gso_type to unsigned int.

Addresses-Coverity-ID: 1462223
Fixes: 0c19f846 ("net: accept UFO datagrams from tuntap and packet")
Signed-off-by: NGustavo A. R. Silva <garsilva@embeddedor.com>
Acked-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

New file seems to have missed the SPDX license scan and update.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Setting the refcount to 0 when allocating a tree to match the number of
switch devices it holds may cause an 'increment on 0; use-after-free',
if CONFIG_REFCOUNT_FULL is enabled.

To fix this, do not decrement the refcount of a newly allocated tree,
increment it when an already allocated tree is found, and decrement it
after the probing of a switch, as done with the previous behavior.

At the same time, make dsa_tree_get and dsa_tree_put accept a NULL
argument to simplify callers, and return the tree after incrementation,
as most kref users like of_node_get and of_node_put do.

Fixes: 8e5bf975 ("net: dsa: simplify tree reference counting")
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Tested-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When using the host personality, VMCI will grab a mutex for any
queue pair access. In the detach callback for the vmci vsock
transport, we call vsock_stream_has_data while holding a spinlock,
and vsock_stream_has_data will access a queue pair.

To avoid this, we can simply omit calling vsock_stream_has_data
for host side queue pairs, since the QPs are empty per default
when the guest has detached.

This bug affects users of VMware Workstation using kernel version
4.4 and later.

Testing: Ran vsock tests between guest and host, and verified that
with this change, the host isn't calling vsock_stream_has_data
during detach. Ran mixedTest between guest and host using both
guest and host as server.

v2: Rebased on top of recent change to sk_state values
Reviewed-by: NAdit Ranadive <aditr@vmware.com>
Reviewed-by: NAditya Sarwade <asarwade@vmware.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NJorgen Hansen <jhansen@vmware.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcf_block_put_ext has assumed that all filters (and thus their goto
actions) are destroyed in RCU callback and thus can not race with our
list iteration. However, that is not true during netns cleanup (see
tcf_exts_get_net comment).

Prevent the user after free by holding all chains (except 0, that one is
already held). foreach_safe is not enough in this case.

To reproduce, run the following in a netns and then delete the ns:
    ip link add dtest type dummy
    tc qdisc add dev dtest ingress
    tc filter add dev dtest chain 1 parent ffff: handle 1 prio 1 flower action goto chain 2

Fixes: 822e86d9 ("net_sched: remove tcf_block_put_deferred()")
Signed-off-by: NRoman Kapl <code@rkapl.cz>
Acked-by: NJiri Pirko <jiri@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 86dabda4 ("net: thunderbolt: Clear finished Tx frame bus
address in tbnet_tx_callback()") fixed a DMA-API violation where the
driver called dma_unmap_page() in tbnet_free_buffers() for a bus address
that might already be unmapped. The fix was to zero out the bus address
of a frame in tbnet_tx_callback().

However, as pointed out by David Miller, zero might well be valid
mapping (at least in theory) so it is not good idea to use it here.

It turns out that we don't need the whole map/unmap dance for Tx buffers
at all. Instead we can map the buffers when they are initially allocated
and unmap them when the interface is brought down. In between we just
DMA sync the buffers for the CPU or device as needed.
Signed-off-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't offload IP header checksum to NIC.

This fixes a previous patch which enabled checksum offloading
for both IPv4 and IPv6 packets.  So L3 checksum offload was
getting enabled for IPv6 pkts.  And HW is dropping these pkts
as it assumes the pkt is IPv4 when IP csum offload is set
in the SQ descriptor.

Fixes:  3a9024f5 ("net: thunderx: Enable TSO and checksum offloads for ipv6")
Signed-off-by: NSunil Goutham <sgoutham@cavium.com>
Signed-off-by: NAleksey Makarov <aleksey.makarov@auriga.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When regulatory database certificates are built-in, they're
currently using the SHA256 digest algorithm, so add that to
the build in that case.

Also add a note that for custom certificates, one may need
to add the right algorithms.
Reported-by: NFlorian Fainelli <f.fainelli@gmail.com>
Tested-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

The function pci_unmap_page is obsolete. So it is replaced with
the function dma_unmap_page.

CC: Srinivas Eeda <srinivas.eeda@oracle.com>
CC: Joe Jin <joe.jin@oracle.com>
CC: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: NZhu Yanjun <yanjun.zhu@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

David Howells says:

====================
rxrpc: Fixes and improvements

Here's a set of patches that fix and improve some stuff in the AF_RXRPC
protocol:

The patches are:

 (1) Unlock mutex returned by rxrpc_accept_call().

 (2) Don't set connection upgrade by default.

 (3) Differentiate the call->user_mutex used by the kernel from that used
     by userspace calling sendmsg() to avoid lockdep warnings.

 (4) Delay terminal ACK transmission to a work queue so that it can be
     replaced by the next call if there is one.

 (5) Split the call parameters from the connection parameters so that more
     call-specific parameters can be passed through.

 (6) Fix the call timeouts to work the same as for other RxRPC/AFS
     implementations.

 (7) Don't transmit DELAY ACKs immediately, but instead delay them slightly
     so that can be discarded or can represent more packets.

 (8) Use RTT to calculate certain protocol timeouts.

 (9) Add a timeout to detect lost ACK/DATA packets.

(10) Add a keepalive function so that we ping the peer if we haven't
     transmitted for a short while, thereby keeping intervening firewall
     routes open.

(11) Make service endpoints expire like they're supposed to so that the UDP
     port can be reused.

(12) Fix connection expiry timers to make cleanup happen in a more timely
     fashion.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix the rxrpc connection expiry timers so that connections for closed
AF_RXRPC sockets get deleted in a more timely fashion, freeing up the
transport UDP port much more quickly.

 (1) Replace the delayed work items with work items plus timers so that
     timer_reduce() can be used to shorten them and so that the timer
     doesn't requeue the work item if the net namespace is dead.

 (2) Don't use queue_delayed_work() as that won't alter the timeout if the
     timer is already running.

 (3) Don't rearm the timers if the network namespace is dead.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

RxRPC service endpoints expire like they're supposed to by the following
means:

 (1) Mark dead rxrpc_net structs (with ->live) rather than twiddling the
     global service conn timeout, otherwise the first rxrpc_net struct to
     die will cause connections on all others to expire immediately from
     then on.

 (2) Mark local service endpoints for which the socket has been closed
     (->service_closed) so that the expiration timeout can be much
     shortened for service and client connections going through that
     endpoint.

 (3) rxrpc_put_service_conn() needs to schedule the reaper when the usage
     count reaches 1, not 0, as idle conns have a 1 count.

 (4) The accumulator for the earliest time we might want to schedule for
     should be initialised to jiffies + MAX_JIFFY_OFFSET, not ULONG_MAX as
     the comparison functions use signed arithmetic.

 (5) Simplify the expiration handling, adding the expiration value to the
     idle timestamp each time rather than keeping track of the time in the
     past before which the idle timestamp must go to be expired.  This is
     much easier to read.

 (6) Ignore the timeouts if the net namespace is dead.

 (7) Restart the service reaper work item rather the client reaper.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

We need to transmit a packet every so often to act as a keepalive for the
peer (which has a timeout from the last time it received a packet) and also
to prevent any intervening firewalls from closing the route.

Do this by resetting a timer every time we transmit a packet.  If the timer
ever expires, we transmit a PING ACK packet and thereby also elicit a PING
RESPONSE ACK from the other side - which prevents our last-rx timeout from
expiring.

The timer is set to 1/6 of the last-rx timeout so that we can detect the
other side going away if it misses 6 replies in a row.

This is particularly necessary for servers where the processing of the
service function may take a significant amount of time.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Add an extra timeout that is set/updated when we send a DATA packet that
has the request-ack flag set.  This allows us to detect if we don't get an
ACK in response to the latest flagged packet.

The ACK packet is adjudged to have been lost if it doesn't turn up within
2*RTT of the transmission.

If the timeout occurs, we schedule the sending of a PING ACK to find out
the state of the other side.  If a new DATA packet is ready to go sooner,
we cancel the sending of the ping and set the request-ack flag on that
instead.

If we get back a PING-RESPONSE ACK that indicates a lower tx_top than what
we had at the time of the ping transmission, we adjudge all the DATA
packets sent between the response tx_top and the ping-time tx_top to have
been lost and retransmit immediately.

Rather than sending a PING ACK, we could just pick a DATA packet and
speculatively retransmit that with request-ack set.  It should result in
either a REQUESTED ACK or a DUPLICATE ACK which we can then use in lieu the
a PING-RESPONSE ACK mentioned above.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Express protocol timeouts for data retransmission and deferred ack
generation in terms on RTT rather than specified timeouts once we have
sufficient RTT samples.

For the moment, this requires just one RTT sample to be able to use this
for ack deferral and two for data retransmission.

The data retransmission timeout is set at RTT*1.5 and the ACK deferral
timeout is set at RTT.

Note that the calculated timeout is limited to a minimum of 4ns to make
sure it doesn't happen too quickly.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Don't transmit a DELAY ACK immediately on proposal when the Rx window is
rotated, but rather defer it to the work function.  This means that we have
a chance to queue/consume more received packets before we actually send the
DELAY ACK, or even cancel it entirely, thereby reducing the number of
packets transmitted.

We do, however, want to continue sending other types of packet immediately,
particularly REQUESTED ACKs, as they may be used for RTT calculation by the
other side.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Fix the rxrpc call expiration timeouts and make them settable from
userspace.  By analogy with other rx implementations, there should be three
timeouts:

 (1) "Normal timeout"

     This is set for all calls and is triggered if we haven't received any
     packets from the peer in a while.  It is measured from the last time
     we received any packet on that call.  This is not reset by any
     connection packets (such as CHALLENGE/RESPONSE packets).

     If a service operation takes a long time, the server should generate
     PING ACKs at a duration that's substantially less than the normal
     timeout so is to keep both sides alive.  This is set at 1/6 of normal
     timeout.

 (2) "Idle timeout"

     This is set only for a service call and is triggered if we stop
     receiving the DATA packets that comprise the request data.  It is
     measured from the last time we received a DATA packet.

 (3) "Hard timeout"

     This can be set for a call and specified the maximum lifetime of that
     call.  It should not be specified by default.  Some operations (such
     as volume transfer) take a long time.

Allow userspace to set/change the timeouts on a call with sendmsg, using a
control message:

	RXRPC_SET_CALL_TIMEOUTS

The data to the message is a number of 32-bit words, not all of which need
be given:

	u32 hard_timeout;	/* sec from first packet */
	u32 idle_timeout;	/* msec from packet Rx */
	u32 normal_timeout;	/* msec from data Rx */

This can be set in combination with any other sendmsg() that affects a
call.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

When rxrpc_sendmsg() parses the control message buffer, it places the
parameters extracted into a structure, but lumps together call parameters
(such as user call ID) with operation parameters (such as whether to send
data, send an abort or accept a call).

Split the call parameters out into their own structure, a copy of which is
then embedded in the operation parameters struct.

The call parameters struct is then passed down into the places that need it
instead of passing the individual parameters.  This allows for extra call
parameters to be added.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Delay terminal ACK transmission on a client call by deferring it to the
connection processor.  This allows it to be skipped if we can send the next
call instead, the first DATA packet of which will implicitly ack this call.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Provide a different lockdep key for rxrpc_call::user_mutex when the call is
made on a kernel socket, such as by the AFS filesystem.

The problem is that lockdep registers a false positive between userspace
calling the sendmsg syscall on a user socket where call->user_mutex is held
whilst userspace memory is accessed whereas the AFS filesystem may perform
operations with mmap_sem held by the caller.

In such a case, the following warning is produced.

======================================================
WARNING: possible circular locking dependency detected
4.14.0-fscache+ #243 Tainted: G            E
------------------------------------------------------
modpost/16701 is trying to acquire lock:
 (&vnode->io_lock){+.+.}, at: [<ffffffffa000fc40>] afs_begin_vnode_operation+0x33/0x77 [kafs]

but task is already holding lock:
 (&mm->mmap_sem){++++}, at: [<ffffffff8104376a>] __do_page_fault+0x1ef/0x486

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #3 (&mm->mmap_sem){++++}:
       __might_fault+0x61/0x89
       _copy_from_iter_full+0x40/0x1fa
       rxrpc_send_data+0x8dc/0xff3
       rxrpc_do_sendmsg+0x62f/0x6a1
       rxrpc_sendmsg+0x166/0x1b7
       sock_sendmsg+0x2d/0x39
       ___sys_sendmsg+0x1ad/0x22b
       __sys_sendmsg+0x41/0x62
       do_syscall_64+0x89/0x1be
       return_from_SYSCALL_64+0x0/0x75

-> #2 (&call->user_mutex){+.+.}:
       __mutex_lock+0x86/0x7d2
       rxrpc_new_client_call+0x378/0x80e
       rxrpc_kernel_begin_call+0xf3/0x154
       afs_make_call+0x195/0x454 [kafs]
       afs_vl_get_capabilities+0x193/0x198 [kafs]
       afs_vl_lookup_vldb+0x5f/0x151 [kafs]
       afs_create_volume+0x2e/0x2f4 [kafs]
       afs_mount+0x56a/0x8d7 [kafs]
       mount_fs+0x6a/0x109
       vfs_kern_mount+0x67/0x135
       do_mount+0x90b/0xb57
       SyS_mount+0x72/0x98
       do_syscall_64+0x89/0x1be
       return_from_SYSCALL_64+0x0/0x75

-> #1 (k-sk_lock-AF_RXRPC){+.+.}:
       lock_sock_nested+0x74/0x8a
       rxrpc_kernel_begin_call+0x8a/0x154
       afs_make_call+0x195/0x454 [kafs]
       afs_fs_get_capabilities+0x17a/0x17f [kafs]
       afs_probe_fileserver+0xf7/0x2f0 [kafs]
       afs_select_fileserver+0x83f/0x903 [kafs]
       afs_fetch_status+0x89/0x11d [kafs]
       afs_iget+0x16f/0x4f8 [kafs]
       afs_mount+0x6c6/0x8d7 [kafs]
       mount_fs+0x6a/0x109
       vfs_kern_mount+0x67/0x135
       do_mount+0x90b/0xb57
       SyS_mount+0x72/0x98
       do_syscall_64+0x89/0x1be
       return_from_SYSCALL_64+0x0/0x75

-> #0 (&vnode->io_lock){+.+.}:
       lock_acquire+0x174/0x19f
       __mutex_lock+0x86/0x7d2
       afs_begin_vnode_operation+0x33/0x77 [kafs]
       afs_fetch_data+0x80/0x12a [kafs]
       afs_readpages+0x314/0x405 [kafs]
       __do_page_cache_readahead+0x203/0x2ba
       filemap_fault+0x179/0x54d
       __do_fault+0x17/0x60
       __handle_mm_fault+0x6d7/0x95c
       handle_mm_fault+0x24e/0x2a3
       __do_page_fault+0x301/0x486
       do_page_fault+0x236/0x259
       page_fault+0x22/0x30
       __clear_user+0x3d/0x60
       padzero+0x1c/0x2b
       load_elf_binary+0x785/0xdc7
       search_binary_handler+0x81/0x1ff
       do_execveat_common.isra.14+0x600/0x888
       do_execve+0x1f/0x21
       SyS_execve+0x28/0x2f
       do_syscall_64+0x89/0x1be
       return_from_SYSCALL_64+0x0/0x75

other info that might help us debug this:

Chain exists of:
  &vnode->io_lock --> &call->user_mutex --> &mm->mmap_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&mm->mmap_sem);
                               lock(&call->user_mutex);
                               lock(&mm->mmap_sem);
  lock(&vnode->io_lock);

 *** DEADLOCK ***

1 lock held by modpost/16701:
 #0:  (&mm->mmap_sem){++++}, at: [<ffffffff8104376a>] __do_page_fault+0x1ef/0x486

stack backtrace:
CPU: 0 PID: 16701 Comm: modpost Tainted: G            E   4.14.0-fscache+ #243
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
Call Trace:
 dump_stack+0x67/0x8e
 print_circular_bug+0x341/0x34f
 check_prev_add+0x11f/0x5d4
 ? add_lock_to_list.isra.12+0x8b/0x8b
 ? add_lock_to_list.isra.12+0x8b/0x8b
 ? __lock_acquire+0xf77/0x10b4
 __lock_acquire+0xf77/0x10b4
 lock_acquire+0x174/0x19f
 ? afs_begin_vnode_operation+0x33/0x77 [kafs]
 __mutex_lock+0x86/0x7d2
 ? afs_begin_vnode_operation+0x33/0x77 [kafs]
 ? afs_begin_vnode_operation+0x33/0x77 [kafs]
 ? afs_begin_vnode_operation+0x33/0x77 [kafs]
 afs_begin_vnode_operation+0x33/0x77 [kafs]
 afs_fetch_data+0x80/0x12a [kafs]
 afs_readpages+0x314/0x405 [kafs]
 __do_page_cache_readahead+0x203/0x2ba
 ? filemap_fault+0x179/0x54d
 filemap_fault+0x179/0x54d
 __do_fault+0x17/0x60
 __handle_mm_fault+0x6d7/0x95c
 handle_mm_fault+0x24e/0x2a3
 __do_page_fault+0x301/0x486
 do_page_fault+0x236/0x259
 page_fault+0x22/0x30
RIP: 0010:__clear_user+0x3d/0x60
RSP: 0018:ffff880071e93da0 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000000000011c RCX: 000000000000011c
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000060f720
RBP: 000000000060f720 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffff8800b5459b68 R12: ffff8800ce150e00
R13: 000000000060f720 R14: 00000000006127a8 R15: 0000000000000000
 padzero+0x1c/0x2b
 load_elf_binary+0x785/0xdc7
 search_binary_handler+0x81/0x1ff
 do_execveat_common.isra.14+0x600/0x888
 do_execve+0x1f/0x21
 SyS_execve+0x28/0x2f
 do_syscall_64+0x89/0x1be
 entry_SYSCALL64_slow_path+0x25/0x25
RIP: 0033:0x7fdb6009ee07
RSP: 002b:00007fff566d9728 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 000055ba57280900 RCX: 00007fdb6009ee07
RDX: 000055ba5727f270 RSI: 000055ba5727cac0 RDI: 000055ba57280900
RBP: 000055ba57280900 R08: 00007fff566d9700 R09: 0000000000000000
R10: 000055ba5727cac0 R11: 0000000000000246 R12: 0000000000000000
R13: 000055ba5727cac0 R14: 000055ba5727f270 R15: 0000000000000000
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Don't set upgrade by default when creating a call from sendmsg().  This is
a holdover from when I was testing the code.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

The caller of rxrpc_accept_call() must release the lock on call->user_mutex
returned by that function.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Pull networking fixes from David Miller:

 1) Fix PCI IDs of 9000 series iwlwifi devices, from Luca Coelho.

 2) bpf offload bug fixes from Jakub Kicinski.

 3) Fix bpf verifier to NOP out code which is dead at run time because
    due to branch pruning the verifier will not explore such
    instructions. From Alexei Starovoitov.

 4) Fix crash when deleting secondary chains in packet scheduler
    classifier. From Roman Kapl.

 5) Fix buffer management bugs in smc, from Ursula Braun.

 6) Fix regression in anycast route handling, from David Ahern.

 7) Fix link settings regression in r8169, from Tobias Jakobi.

 8) Add back enough UFO support so that live migration still works, from
    Willem de Bruijn.

 9) Linearize enough packet data for the full extent to which the ipvlan
    code will inspect the packet headers, from Gao Feng.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (46 commits)
  ipvlan: Fix insufficient skb linear check for ipv6 icmp
  ipvlan: Fix insufficient skb linear check for arp
  geneve: only configure or fill UDP_ZERO_CSUM6_RX/TX info when CONFIG_IPV6
  net: dsa: bcm_sf2: Clear IDDQ_GLOBAL_PWR bit for PHY
  net: accept UFO datagrams from tuntap and packet
  net: realtek: r8169: implement set_link_ksettings()
  net: ipv6: Fixup device for anycast routes during copy
  net/smc: Fix preinitialization of buf_desc in __smc_buf_create()
  net/smc: use sk_rcvbuf as start for rmb creation
  ipv6: Do not consider linkdown nexthops during multipath
  net: sched: fix crash when deleting secondary chains
  net: phy: cortina: add missing MODULE_DESCRIPTION/AUTHOR/LICENSE
  bpf: fix branch pruning logic
  bpf: change bpf_perf_event_output arg5 type to ARG_CONST_SIZE_OR_ZERO
  bpf: change bpf_probe_read_str arg2 type to ARG_CONST_SIZE_OR_ZERO
  bpf: remove explicit handling of 0 for arg2 in bpf_probe_read
  bpf: introduce ARG_PTR_TO_MEM_OR_NULL
  i40evf: Use smp_rmb rather than read_barrier_depends
  fm10k: Use smp_rmb rather than read_barrier_depends
  igb: Use smp_rmb rather than read_barrier_depends
  ...

Pull x86 platform driver fixes from Darren Hart:
 "Fix two issues resulting from the dell-smbios refactoring and
  introduction of the dell-smbios-wmi dispatcher.

  The first ensures a proper error code is returned when kzalloc fails.

  The second avoids an issue in older Dell BIOS implementations which
  would fail if the more complex calls were made by limiting those
  platforms to the simple calls such as those used by the existing
  dell-laptop and dell-wmi drivers, preserving their functionality prior
  to the addition of the dell-smbios-wmi dispatcher"

* tag 'platform-drivers-x86-v4.15-2' of git://git.infradead.org/linux-platform-drivers-x86:
  platform/x86: dell-laptop: fix error return code in dell_init()
  platform/x86: dell-smbios-wmi: Disable userspace interface if missing hotfix

Pull SCSI fixes from James Bottomley:
 "Two basic fixes: one for the sparse problem with the blacklist flags
  and another for a hang forever in bnx2i"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: Use 'blist_flags_t' for scsi_devinfo flags
  scsi: bnx2fc: Fix hung task messages when a cleanup response is not received during abort

Pull sound fixes from Takashi Iwai:
 "All commits found here are small fixes for regression or stable:

   - PCM timestamp behavior fix that could be seen as a regression

   - Remove spurious WARN_ON() from ALSA timer 32bit compat ioctl

   - HD-audio HDMI/DP channel mapping fix for 32bit archs

   - Fix the previous fix for HD-audio initialization code

   - More hardening USB-audio against malicious USB descriptors

   - HD-audio quirks/fixes (Realtek codec, AMD controller)

   - Missing help text for the recent Intel SST kconfig change"

* tag 'sound-fix-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda: Add Raven PCI ID
  ALSA: hda/realtek - Fix ALC700 family no sound issue
  ALSA: hda - Fix yet remaining issue with vmaster 0dB initialization
  ALSA: usb-audio: Add sanity checks in v2 clock parsers
  ALSA: usb-audio: Fix potential zero-division at parsing FU
  ALSA: usb-audio: Fix potential out-of-bound access at parsing SU
  ALSA: usb-audio: Add sanity checks to FE parser
  ALSA: timer: Remove kernel warning at compat ioctl error paths
  ALSA: pcm: update tstamp only if audio_tstamp changed
  ALSA: hda/realtek: Add headset mic support for Intel NUC Skull Canyon
  ALSA: hda: Fix too short HDMI/DP chmap reporting
  ALSA: usb-audio: uac1: Invalidate ctl on interrupt
  ALSA: hda/realtek - Fix ALC275 no sound issue
  ASoC: Intel: Add help text for SND_SOC_INTEL_SST_TOPLEVEL

Pull more drm updates from Dave Airlie:
 "Fixes/cleanups for rc1, non-desktop flags for VR

   - remove the MSM dt-bindings file Rob managed to push in the previous
     pull.

   - add a property/edid quirk to denote HMD devices, I had these
     hanging around for a few weeks and Keith had done some work on
     them, they are fairly self contained and small, and only affect
     people using HTC Vive VR headsets so far.

   - amdgpu, tegra, tilcdc, fsl fixes

   - some imx-drm cleanups I missed, these seemed pretty small, and no
     reason to hold off.

  I have one TTM regression fix (fixes bochs-vga in qemu) sitting
  locally awaiting review I'll probably send that in a separate pull
  request tomorrow"

* tag 'drm-for-v4.15-part2' of git://people.freedesktop.org/~airlied/linux: (33 commits)
  dt-bindings: remove file that was added accidentally
  drm/edid: quirk HTC vive headset as non-desktop. [v2]
  drm/fb: add support for not enabling fbcon on non-desktop displays [v2]
  drm: add connector info/property for non-desktop displays [v2]
  drm/amdgpu: fix rmmod KCQ disable failed error
  drm/amdgpu: fix kernel hang when starting VNC server
  drm/amdgpu: don't skip attributes when powerplay is enabled
  drm/amd/pp: fix typecast error in powerplay.
  drm/tilcdc: Remove obsolete "ti,tilcdc,slave" dts binding support
  drm/tegra: sor: Reimplement pad clock
  Revert "drm/radeon: dont switch vt on suspend"
  drm/amd/amdgpu: fix over-bound accessing in amdgpu_cs_wait_any_fence
  drm/amd/powerplay: fix unfreeze level smc message for smu7
  drm/amdgpu:fix memleak
  drm/amdgpu:fix memleak in takedown
  drm/amd/pp: fix dpm randomly failed on Vega10
  drm/amdgpu: set f_mapping on exported DMA-bufs
  drm/amdgpu: Properly allocate VM invalidate eng v2
  drm/fsl-dcu: enable IRQ before drm_atomic_helper_resume()
  drm/fsl-dcu: avoid disabling pixel clock twice on suspend
  ...