The connection link attributes are not used and expose no valuable
information.
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>

If recvmsg is called with a destination buffer that is too small to
receive the contents of skb in its entirety, the return value from
recvmsg was inconsistent with common SOCK_SEQPACKET or SOCK_DGRAM
semantics.

If destination buffer provided by userspace is too small (e.g. len <
copied), then MSG_TRUNC flag is set and copied is returned.  Instead, it
should return the length of the message, which is consistent with how
other datagram based sockets act.  Quoting 'man recv':

"All  three calls return the length of the message on successful comple‐
tion.  If a message is too long to fit in the supplied  buffer,  excess
bytes  may  be discarded depending on the type of socket the message is
received from."

and

"MSG_TRUNC (since Linux 2.2)

    For   raw   (AF_PACKET),   Internet   datagram   (since    Linux
    2.4.27/2.6.8),  netlink  (since Linux 2.6.22), and UNIX datagram
    (since Linux 3.4) sockets: return the real length of the packet
    or datagram, even when it was longer than the passed buffer."
Signed-off-by: NDenis Kenzior <denkenz@gmail.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

If recvmsg is called with a destination buffer that is too small to
receive the contents of skb in its entirety, the return value from
recvmsg was inconsistent with common SOCK_SEQPACKET or SOCK_DGRAM
semantics.

If destination buffer provided by userspace is too small (e.g. len <
copied), then MSG_TRUNC flag is set and copied is returned.  Instead, it
should return the length of the message, which is consistent with how
other datagram based sockets act.  Quoting 'man recv':

"All  three calls return the length of the message on successful comple‐
tion.  If a message is too long to fit in the supplied  buffer,  excess
bytes  may  be discarded depending on the type of socket the message is
received from."

and

"MSG_TRUNC (since Linux 2.2)

    For   raw   (AF_PACKET),   Internet   datagram   (since    Linux
    2.4.27/2.6.8),  netlink  (since Linux 2.6.22), and UNIX datagram
    (since Linux 3.4) sockets: return the real length of the packet
    or datagram, even when it was longer than the passed buffer."
Signed-off-by: NDenis Kenzior <denkenz@gmail.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

SMP does ECB crypto on stack buffers.  This is complicated and
fragile, and it will not work if the stack is virtually allocated.

Switch to the crypto_cipher interface, which is simpler and safer.
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Acked-by: NJohan Hedberg <johan.hedberg@intel.com>
Tested-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

It is time to add netdev_lockdep_set_classes() helper
so that lockdep annotations per device type are easier to manage.

This removes a lot of copies and missing annotations.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of using a single bit (__QDISC___STATE_RUNNING)
in sch->__state, use a seqcount.

This adds lockdep support, but more importantly it will allow us
to sample qdisc/class statistics without having to grab qdisc root lock.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With all the latest fixes applied, I am still able to reproduce this
(and other) warning(s):
WARNING: CPU: 1 PID: 19684 at ../kernel/workqueue.c:4092 destroy_workqueue+0x70a/0x770()
...
Call Trace:
 [<ffffffff819fee81>] ? dump_stack+0xb3/0x112
 [<ffffffff8117377e>] ? warn_slowpath_common+0xde/0x140
 [<ffffffff811ce68a>] ? destroy_workqueue+0x70a/0x770
 [<ffffffff811739ae>] ? warn_slowpath_null+0x2e/0x40
 [<ffffffff811ce68a>] ? destroy_workqueue+0x70a/0x770
 [<ffffffffa0c944c9>] ? hci_unregister_dev+0x2a9/0x720 [bluetooth]
 [<ffffffffa0b301db>] ? vhci_release+0x7b/0xf0 [hci_vhci]
 [<ffffffffa0b30160>] ? vhci_flush+0x50/0x50 [hci_vhci]
 [<ffffffff8117cd73>] ? do_exit+0x863/0x2b90

This is due to race present in the hci_unregister_dev path.
hdev->power_on work races with hci_dev_do_close. One tries to open,
the other tries to close, leading to warning like the above. (Another
example is a warning in kobject_get or kobject_put depending on who
wins the race.)

Fix this by switching those two racers to ensure hdev->power_on never
triggers while hci_dev_do_close is in progress.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Replace all trans_start updates with netif_trans_update helper.
change was done via spatch:

struct net_device *d;
@@
- d->trans_start = jiffies
+ netif_trans_update(d)

Compile tested only.

Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: linux-xtensa@linux-xtensa.org
Cc: linux1394-devel@lists.sourceforge.net
Cc: linux-rdma@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: MPT-FusionLinux.pdl@broadcom.com
Cc: linux-scsi@vger.kernel.org
Cc: linux-can@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Cc: linux-hams@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: linux-wireless@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: devel@driverdev.osuosl.org
Cc: b.a.t.m.a.n@lists.open-mesh.org
Cc: linux-bluetooth@vger.kernel.org
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Acked-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: NMugunthan V N <mugunthanvnm@ti.com>
Acked-by: NAntonio Quartulli <a@unstable.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The memcpy of ipv6 header destination address to the skb control block
(sbk->cb) in header_create() results in currupted memory when bt_xmit()
is issued. The skb->cb is "released" in the return of header_create()
making room for lower layer to minipulate the skb->cb.

The value retrieved in bt_xmit is not persistent across header creation
and sending, and the lower layer will overwrite portions of skb->cb,
making the copied destination address wrong.

The memory corruption will lead to non-working multicast as the first 4
bytes of the copied destination address is replaced by a value that
resolves into a non-multicast prefix.

This fix removes the dependency on the skb control block between header
creation and send, by moving the destination address memcpy to the send
function path (setup_create, which is called from bt_xmit).
Signed-off-by: NGlenn Ruben Bakke <glenn.ruben.bakke@nordicsemi.no>
Acked-by: NJukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org # 4.5+

sock_owned_by_user should not be used without socket lock held. It seems
to be a common practice to check .owned before lock reclassification, so
provide a little help to abstract this check away.

Cc: linux-cifs@vger.kernel.org
Cc: linux-bluetooth@vger.kernel.org
Cc: linux-nfs@vger.kernel.org
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch changes the naming for interface private data for lowpan
intefaces. The current private data scheme is:

-------------------------------------------------
|    6LoWPAN Generic   |    LinkLayer 6LoWPAN   |
-------------------------------------------------

the current naming schemes are:

- 6LoWPAN Generic:
  - lowpan_priv
- LinkLayer 6LoWPAN:
  - BTLE
    - lowpan_dev
  - 802.15.4:
    - lowpan_dev_info

the new naming scheme with this patch will be:

- 6LoWPAN Generic:
  - lowpan_dev
- LinkLayer 6LoWPAN:
  - BTLE
    - lowpan_btle_dev
  - 802.15.4:
    - lowpan_802154_dev
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Reviewed-by: Stefan Schmidt<stefan@osg.samsung.com>
Acked-by: NJukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Update the security level check to allow setting BT_SECURITY_FIPS for
an L2CAP socket.
Signed-off-by: NPatrik Flykt <patrik.flykt@linux.intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

In case of buggy controllers send advertising packet types that we
don't know of we should simply ignore them instead of trying to react
to them in some (potentially wrong) way.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

If we're dealing with a single-mode controller or BR/EDR is disable
for a dual-mode one, the NO_BREDR flag needs to be unconditionally
present in the advertising data. This patch moves it out from behind
an extra condition to be always set in the create_instance_adv_data()
function if BR/EDR is disabled.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The Add Advertising command handler does the appropriate checks for
the AD and Scan Response data, however fails to take into account the
general length of the mgmt command itself, which could lead to
potential buffer overflows. This patch adds the necessary check that
the mgmt command length is consistent with the given ad and scan_rsp
lengths.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org

A recent change added MGMT_ADV_FLAG_DISCOV to the flags returned by
get_adv_instance_flags(), however failed to take into account limited
discoverable mode. This patch fixes the issue by setting the correct
discoverability flag in the AD data.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Increment the mgmt revision due to the recently added limited
privacy mode.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Introduce a limited privacy mode indicated by value 0x02 to the mgmt
Set Privacy command.

With value 0x02 the kernel will use privacy mode with a resolvable
private address. In case the controller is bondable and discoverable
the identity address will be used.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When lookup up the advertising instance flags for the default
advertising instance (0) the discoverable flag should be filled in
based on the HCI_DISCOVERABLE flag.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Minor fix to not do the memset until the variable it clears is
actually used.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When the HCI_AUTO_OFF flag is cleared, the power_off delayed work need
to be cancel or HCI will be powered off even if it's managed.
Signed-off-by: NWei-Ning Huang <wnhuang@chromium.org>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Recently a managed version of led_trigger_register was introduced.
Using devm_led_trigger_register allows to simplify the LED trigger code.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Add support for LED triggers to the Bluetooth subsystem and add kernel
config symbol BT_LEDS for it.

For now one trigger for indicating "HCI is powered up" is supported.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

In commit 44d27137 ("Bluetooth: Compress the size of struct
hci_ctrl") we squashed down the size of the structure by using a union
with the assumption that all users would use the flag to determine
whether we had a req_complete or a req_complete_skb.

Unfortunately we had a case in hci_req_cmd_complete() where we weren't
looking at the flag.  This can result in a situation where we might be
storing a hci_req_complete_skb_t in a hci_req_complete_t variable, or
vice versa.

During some testing I found at least one case where the function
hci_req_sync_complete() was called improperly because the kernel thought
that it didn't require an SKB.  Looking through the stack in kgdb I
found that it was called by hci_event_packet() and that
hci_event_packet() had both of its locals "req_complete" and
"req_complete_skb" pointing to the same place: both to
hci_req_sync_complete().

Let's make sure we always check the flag.

For more details on debugging done, see <http://crbug.com/588288>.

Fixes: 44d27137 ("Bluetooth: Compress the size of struct hci_ctrl")
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Acked-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The commit cad20c27 was supposed to
fix handling of devices first using public addresses and then
switching to RPAs after pairing. Unfortunately it missed a couple of
key places in the code.

1. When evaluating which devices should be removed from the existing
white list we also need to consider whether we have an IRK for them or
not, i.e. a call to hci_find_irk_by_addr() is needed.

2. In smp_notify_keys() we should not be requiring the knowledge of
the RPA, but should simply keep the IRK around if the other conditions
require it.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org # 4.4+

At least the l2cap_add_psm() routine depends on the source address
type being properly set to know what auto-allocation ranges to use, so
the assignment to l2cap_chan needs to happen before this.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The LE dynamic PSM range is different from BR/EDR (0x0080 - 0x00ff)
and doesn't have requirements relating to parity, so separate checks
are needed.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Having proper defines makes the code a bit readable, it also avoids
duplicating hard-coded values since these are also needed when
auto-allocating PSM values (in a subsequent patch).
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch replaces uses of blkcipher with skcipher and the long
obsolete hash interface with shash.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Acked-by: NMarcel Holtmann <marcel@holtmann.org>

This patch fixes incorrect handling of the 6lowpan packets that contain
uncompressed IPv6 header.

RFC4944 specifies a special dispatch for 6lowpan to carry uncompressed
IPv6 header. This dispatch (1 byte long) has to be removed during
reception and skb data pointer has to be moved. To correctly point in
the beginning of the IPv6 header the dispatch byte has to be pulled off
before packet can be processed by netif_rx_in().

Test scenario: IPv6 packets are not correctly interpreted by the network
layer when IPv6 header is not compressed (e.g. ICMPv6 Echo Reply is not
propagated correctly to the ICMPv6 layer because the extra byte will make
the header look corrupted).

Similar approach is done for IEEE 802.15.4.
Signed-off-by: NLukasz Duda <lukasz.duda@nordicsemi.no>
Signed-off-by: NGlenn Ruben Bakke <glenn.ruben.bakke@nordicsemi.no>
Acked-by: NJukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Cc: stable@vger.kernel.org # 4.4+

The fixes provided in this patch assigns a valid net_device structure to
skb before dispatching it for further processing.

Scenario #1:
============

Bluetooth 6lowpan receives an uncompressed IPv6 header, and dispatches it
to netif. The following error occurs:

Null pointer dereference error #1 crash log:

[  845.854013] BUG: unable to handle kernel NULL pointer dereference at
               0000000000000048
[  845.855785] IP: [<ffffffff816e3d36>] enqueue_to_backlog+0x56/0x240
...
[  845.909459] Call Trace:
[  845.911678]  [<ffffffff816e3f64>] netif_rx_internal+0x44/0xf0

The first modification fixes the NULL pointer dereference error by
assigning dev to the local_skb in order to set a valid net_device before
processing the skb by netif_rx_ni().

Scenario #2:
============

Bluetooth 6lowpan receives an UDP compressed message which needs further
decompression by nhc_udp. The following error occurs:

Null pointer dereference error #2 crash log:

[   63.295149] BUG: unable to handle kernel NULL pointer dereference at
               0000000000000840
[   63.295931] IP: [<ffffffffc0559540>] udp_uncompress+0x320/0x626
               [nhc_udp]

The second modification fixes the NULL pointer dereference error by
assigning dev to the local_skb in the case of a udp compressed packet.
The 6lowpan udp_uncompress function expects that the net_device is set in
the skb when checking lltype.
Signed-off-by: NGlenn Ruben Bakke <glenn.ruben.bakke@nordicsemi.no>
Signed-off-by: NLukasz Duda <lukasz.duda@nordicsemi.no>
Acked-by: NJukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Cc: stable@vger.kernel.org # 4.4+

Instead, allow using string formatting with send_monitor_note()
and access init_utsname().
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch implements the mgmt Start Limited Discovery command. Most
of existing Start Discovery code is reused since the only difference
is the presence of a 'limited' flag as part of the discovery state.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

To make the EIR parsing helper more general purpose, make it return
the found data and its length rather than just saying whether the data
was present or not.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Use list_for_each_entry*() instead of list_for_each*() to simplify
the code.
Signed-off-by: NGeliang Tang <geliangtang@163.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A Linux PC is connected with another device over Bluetooth PAN using a
BNEP interface.

Whenever a packet is tried to be sent over the BNEP interface, the
function "bnep_net_xmit()" in "net/bluetooth/bnep/netdev.c" is called.
This function calls "bnep_net_mc_filter()", which checks (if the
destination address is multicast) if the address is set in a certain
multicast filter (&s->mc_filter). If it is not, then it is not sent out.

This filter is only changed in two other functions, found in
net/bluetooth/bnep/core.c": in "bnep_ctrl_set_mc_filter()", which is
only called if a message of type "BNEP_FILTER_MULTI_ADDR_SET" is
received. Otherwise, it is set in "bnep_add_connection()", where it is
set to a default value which only adds the broadcast address to the
filter:

set_bit(bnep_mc_hash(dev->broadcast), (ulong *) &s->mc_filter);

To sum up, if the BNEP interface does not receive any message of type
"BNEP_FILTER_MULTI_ADDR_SET", it will not send out any messages with
multicast destination addresses except for broadcast.

However, in the BNEP specification (page 27 in
http://grouper.ieee.org/groups/802/15/Bluetooth/BNEP.pdf), it is said
that per default, all multicast addresses should not be filtered, i.e.
the BNEP interface should be able to send packets with any multicast
destination address.

It seems that the default case is wrong: the multicast filter should not
block almost all multicast addresses, but should not filter out any.

This leads to the problem that e.g. Neighbor Solicitation messages sent
with Bluetooth PAN over the BNEP interface to a multicast destination
address other than broadcast are blocked and not sent out.

Therefore, in the default case, we set the mc_filter to ~0LL to not
filter out any multicast addresses.
Signed-off-by: NDanny Schweizer <danny.schweizer@proofnet.de>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

This patch introduces register and unregister functionality for lowpan
interfaces. While register a lowpan interface there are several things
which need to be initialize by the 6lowpan subsystem. Upcoming
functionality need to register/unregister per interface components e.g.
debugfs entry.
Reviewed-by: NStefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: NAlexander Aring <alex.aring@gmail.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

Fix a crash that may happen when bt_accept_dequeue is run after a
Bluetooth connection has been disconnected. bt_accept_unlink was called
after release_sock, permitting bt_accept_unlink to run twice on the same
socket and cause a NULL pointer dereference.

[50510.241632] BUG: unable to handle kernel NULL pointer dereference at 00000000000001a8
[50510.241694] IP: [<ffffffffc01243f7>] bt_accept_unlink+0x47/0xa0 [bluetooth]
[50510.241759] PGD 0
[50510.241776] Oops: 0002 [#1] SMP
[50510.241802] Modules linked in: rtl8192cu rtl_usb rtlwifi rtl8192c_common 8021q garp stp mrp llc rfcomm bnep nls_iso8859_1 intel_rapl x86_pkg_temp_thermal intel_powerclamp coretemp arc4 ath9k ath9k_common ath9k_hw ath kvm eeepc_wmi asus_wmi mac80211 snd_hda_codec_hdmi snd_hda_codec_realtek sparse_keymap crct10dif_pclmul snd_hda_codec_generic crc32_pclmul snd_hda_intel snd_hda_controller cfg80211 snd_hda_codec i915 snd_hwdep snd_pcm ghash_clmulni_intel snd_timer snd soundcore serio_raw cryptd drm_kms_helper drm i2c_algo_bit shpchp ath3k mei_me lpc_ich btusb bluetooth 6lowpan_iphc mei lp parport wmi video mac_hid psmouse ahci libahci r8169 mii
[50510.242279] CPU: 0 PID: 934 Comm: krfcommd Not tainted 3.16.0-49-generic #65~14.04.1-Ubuntu
[50510.242327] Hardware name: ASUSTeK Computer INC. VM40B/VM40B, BIOS 1501 12/09/2014
[50510.242370] task: ffff8800d9068a30 ti: ffff8800d7a54000 task.ti: ffff8800d7a54000
[50510.242413] RIP: 0010:[<ffffffffc01243f7>]  [<ffffffffc01243f7>] bt_accept_unlink+0x47/0xa0 [bluetooth]
[50510.242480] RSP: 0018:ffff8800d7a57d58  EFLAGS: 00010246
[50510.242511] RAX: 0000000000000000 RBX: ffff880119bb8c00 RCX: ffff880119bb8eb0
[50510.242552] RDX: ffff880119bb8eb0 RSI: 00000000fffffe01 RDI: ffff880119bb8c00
[50510.242592] RBP: ffff8800d7a57d60 R08: 0000000000000283 R09: 0000000000000001
[50510.242633] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8800d8da9eb0
[50510.242673] R13: ffff8800d74fdb80 R14: ffff880119bb8c00 R15: ffff8800d8da9c00
[50510.242715] FS:  0000000000000000(0000) GS:ffff88011fa00000(0000) knlGS:0000000000000000
[50510.242761] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[50510.242794] CR2: 00000000000001a8 CR3: 0000000001c13000 CR4: 00000000001407f0
[50510.242835] Stack:
[50510.242849]  ffff880119bb8eb0 ffff8800d7a57da0 ffffffffc0124506 ffff8800d8da9eb0
[50510.242899]  ffff8800d8da9c00 ffff8800d9068a30 0000000000000000 ffff8800d74fdb80
[50510.242949]  ffff8800d6f85208 ffff8800d7a57e08 ffffffffc0159985 000000000000001f
[50510.242999] Call Trace:
[50510.243027]  [<ffffffffc0124506>] bt_accept_dequeue+0xb6/0x180 [bluetooth]
[50510.243085]  [<ffffffffc0159985>] l2cap_sock_accept+0x125/0x220 [bluetooth]
[50510.243128]  [<ffffffff810a1b30>] ? wake_up_state+0x20/0x20
[50510.243163]  [<ffffffff8164946e>] kernel_accept+0x4e/0xa0
[50510.243200]  [<ffffffffc05b97cd>] rfcomm_run+0x1ad/0x890 [rfcomm]
[50510.243238]  [<ffffffffc05b9620>] ? rfcomm_process_rx+0x8a0/0x8a0 [rfcomm]
[50510.243281]  [<ffffffff81091572>] kthread+0xd2/0xf0
[50510.243312]  [<ffffffff810914a0>] ? kthread_create_on_node+0x1c0/0x1c0
[50510.243353]  [<ffffffff8176e9d8>] ret_from_fork+0x58/0x90
[50510.243387]  [<ffffffff810914a0>] ? kthread_create_on_node+0x1c0/0x1c0
[50510.243424] Code: 00 48 8b 93 b8 02 00 00 48 8d 83 b0 02 00 00 48 89 51 08 48 89 0a 48 89 83 b0 02 00 00 48 89 83 b8 02 00 00 48 8b 83 c0 02 00 00 <66> 83 a8 a8 01 00 00 01 48 c7 83 c0 02 00 00 00 00 00 00 f0 ff
[50510.243685] RIP  [<ffffffffc01243f7>] bt_accept_unlink+0x47/0xa0 [bluetooth]
[50510.243737]  RSP <ffff8800d7a57d58>
[50510.243758] CR2: 00000000000001a8
[50510.249457] ---[ end trace bb984f932c4e3ab3 ]---
Signed-off-by: NYichen Zhao <zhaoyichen@google.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

When we're doing background scanning and connection attempts it's
possible we timeout trying to connect and go back to scanning again.
The timeout triggers a HCI_LE_Create_Connection_Cancel which will
trigger a Connection Complete with "Unknown Connection Identifier"
error status. Since we go back to scanning this isn't really a failure
and shouldn't be presented as such to user space through mgmt.

The exception to this is if the connection attempt was due to an
explicit request on an L2CAP socket (indicated by
params->explicit_connect being true). Since the socket will get an
error it's consistent to also notify the failure on mgmt in this case.
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>