This patch adds a simple ECC library that will act as a fundamental
building block for LE Secure Connections. The library has a simple API
consisting of two functions: one for generating a public/private key
pair and another one for generating a Diffie-Hellman key from a local
private key and a remote public key.
The code has been taken from https://github.com/kmackay/easy-ecc and
modified to conform with the kernel coding style.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Most of the LE Secure Connections SMP crypto functions build on top of
the AES-CMAC function. This patch adds access to AES-CMAC in the kernel
crypto subsystem by allocating a crypto_hash handle for it in a similar
way that we have one for AES-CBC.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Depending on whether Secure Connections is enabled or not we may need to add
the link key generation bit to the key distribution. This patch does the
necessary modifications to the build_pairing_cmd() function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that hci_find_ltk_by_addr is the only LTK lookup function there's no
need to keep the long name anymore. This patch shortens the function
name to simply hci_find_ltk.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that LTKs are always looked up based on bdaddr (with EDiv/Rand
checks done after a successful lookup) the hci_find_ltk function is not
needed anymore. This patch removes the function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
LTKs derived from Secure Connections based pairing are symmetric, i.e.
they should match both master and slave role. This patch updates the LTK
lookup functions to ignore the desired role when dealing with SC LTKs.
Furthermore, with Secure Connections the EDiv and Rand values are not
used and should always be set to zero. This patch updates the LTK lookup
to first use the bdaddr as key and then do the necessary verifications
of EDiv and Rand based on whether the found LTK is for SC or not.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Since LE Secure Connections is a purely host-side feature we should
offer the Secure Connections mgmt setting for any adapter with LE
support. This patch updates the supported settings value and the
set_secure_conn command handler accordingly.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Since the HCI_SC_ENABLED flag will also be used for controllers without
BR/EDR Secure Connections support whenever we need to check specifically
for SC for BR/EDR we also need to check that the controller actually
supports it. This patch adds a convenience macro for check all the
necessary conditions and converts the places in the code that need it to
use it.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When the looked-up LTK is one generated by Secure Connections pairing
the security level it gives is BT_SECURITY_FIPS. This patch updates the
LTK request event handler to correctly set this level.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We need a dedicated LTK type for LTK resulting from a Secure Connections
based SMP pairing. This patch adds a new define for it and ensures that
both the New LTK event as well as the Load LTKs command supports it.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch updates the functions which map the SMP authentication
request to a security level and vice-versa to take into account the
Secure Connections feature.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch adds a new SMP flag for tracking whether Secure Connections
is in use and sets the flag when both remote and local side have elected
to use Secure Connections.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If we haven't enabled SC support on our side we should use the same mask
for the authentication requirement as we were using before SC support
was added, otherwise we should use the extended mask for SC.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch adds basic SMP defines for commands, error codes and PDU
definitions for the LE Secure Connections feature.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When we get a Link Key Notification HCI event we should already have a
hci_conn object. This should have been created either in the Connection
Request event handler, the hci_connect_acl() function or the
hci_cs_create_conn() function (if the request was not sent by the
kernel).
Since the only case that we'd end up not having a hci_conn in the Link
Key Notification event handler would be essentially broken hardware it's
safe to simply bail out from the function if this happens.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
To pave the way for future fixed channels to be added easily we should
track both the local and remote mask on a per-L2CAP connection (struct
l2cap_conn) basis. So far the code has used a global variable in a racy
way which anyway needs fixing.
This patch renames the existing conn->fixed_chan_mask that tracked
the remote mask to conn->remote_fixed_chan and adds a new variable
conn->local_fixed_chan to track the local mask. Since the HS support
info is now available in the local mask we can remove the
conn->hs_enabled variable.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The Bluetooth spec states that automatically flushable packets may not
be sent over a LE-U link.
Signed-off-by: Steven Walter <stevenrwalter@gmail.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This patch converts the hdev->link_keys list to be protected through
RCU, thereby eliminating the need to hold the hdev lock while accessing
the list.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When a connection is requested the conn->pending_sec_level value gets
set to whatever level the user requested the connection to be. During
the pairing process there are various sanity checks to try to ensure
that the right length PIN or right IO Capability is used to satisfy the
target security level. However, when we finally get hold of the link key
that is to be used we should still set the actual final security level
from the key type.
This way when we eventually get an Encrypt Change event the correct
value gets copied to conn->sec_level.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In __hci_cmd_sync_ev() and __hci_req_sync() if the hci_req_run() call
fails and we return from the functions we should ensure that the state
doesn't remain in TASK_INTERRUPTIBLE that we just set it to. This patch
fixes missing calls to set_current_state(TASK_RUNNING) in both places.
Reported-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Tested-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Doing things like hci_conn_hash_flush() while holding the hdev lock is
risky since its synchronous pending work cancellation could cause the
L2CAP layer to try to reacquire the hdev lock. Right now there doesn't
seem to be any obvious places where this would for certain happen but
it's already enough to cause lockdep to start warning against the hdev
and the work struct locks being taken in the "wrong" order:
[ +0.000373] mgmt-tester/1603 is trying to acquire lock:
[ +0.000292] ((&conn->pending_rx_work)){+.+.+.}, at: [<c104266d>] flush_work+0x0/0x181
[ +0.000270]
but task is already holding lock:
[ +0.000000] (&hdev->lock){+.+.+.}, at: [<c13b9a80>] hci_dev_do_close+0x166/0x359
[ +0.000000]
which lock already depends on the new lock.
[ +0.000000]
the existing dependency chain (in reverse order) is:
[ +0.000000]
-> #1 (&hdev->lock){+.+.+.}:
[ +0.000000] [<c105ea8f>] lock_acquire+0xe3/0x156
[ +0.000000] [<c140c663>] mutex_lock_nested+0x54/0x375
[ +0.000000] [<c13d644b>] l2cap_recv_frame+0x293/0x1a9c
[ +0.000000] [<c13d7ca4>] process_pending_rx+0x50/0x5e
[ +0.000000] [<c1041a3f>] process_one_work+0x21c/0x436
[ +0.000000] [<c1041e3d>] worker_thread+0x1be/0x251
[ +0.000000] [<c1045a22>] kthread+0x94/0x99
[ +0.000000] [<c140f801>] ret_from_kernel_thread+0x21/0x30
[ +0.000000]
-> #0 ((&conn->pending_rx_work)){+.+.+.}:
[ +0.000000] [<c105e158>] __lock_acquire+0xa07/0xc89
[ +0.000000] [<c105ea8f>] lock_acquire+0xe3/0x156
[ +0.000000] [<c1042696>] flush_work+0x29/0x181
[ +0.000000] [<c1042864>] __cancel_work_timer+0x76/0x8f
[ +0.000000] [<c104288c>] cancel_work_sync+0xf/0x11
[ +0.000000] [<c13d4c18>] l2cap_conn_del+0x72/0x183
[ +0.000000] [<c13d8953>] l2cap_disconn_cfm+0x49/0x55
[ +0.000000] [<c13be37a>] hci_conn_hash_flush+0x7a/0xc3
[ +0.000000] [<c13b9af6>] hci_dev_do_close+0x1dc/0x359
[ +0.012038] [<c13bbe38>] hci_unregister_dev+0x6e/0x1a3
[ +0.000000] [<c12d33c1>] vhci_release+0x28/0x47
[ +0.000000] [<c10dd6a9>] __fput+0xd6/0x154
[ +0.000000] [<c10dd757>] ____fput+0xd/0xf
[ +0.000000] [<c1044bb2>] task_work_run+0x6b/0x8d
[ +0.000000] [<c1001bd2>] do_notify_resume+0x3c/0x3f
[ +0.000000] [<c140fa70>] work_notifysig+0x29/0x31
[ +0.000000]
other info that might help us debug this:
[ +0.000000] Possible unsafe locking scenario:
[ +0.000000] CPU0 CPU1
[ +0.000000] ---- ----
[ +0.000000] lock(&hdev->lock);
[ +0.000000] lock((&conn->pending_rx_work));
[ +0.000000] lock(&hdev->lock);
[ +0.000000] lock((&conn->pending_rx_work));
[ +0.000000]
*** DEADLOCK ***
Fully fixing this would require some quite heavy refactoring to change
how the hdev lock and hci_conn instances are handled together. A simpler
solution for now which this patch takes is to try ensure that the hdev
workqueue is empty before proceeding with the various cleanup calls,
including hci_conn_hash_flush().
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The common short form of "randomizer" is "rand" in many places
(including the Bluetooth specification). The shorter version also makes
for easier to read code with less forced line breaks. This patch renames
all occurences of "randomizer" to "rand" in the Bluetooth subsystem
code.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
For now the mgmt commands dealing with remote OOB data are strictly
BR/EDR-only. This patch fixes missing checks for the passed address type
so that any non-BR/EDR value triggers the appropriate error response.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When passed BDADDR_ANY the Remove Remote OOB Data comand is specified to
clear all entries. This patch adds the necessary check and calls
hci_remote_oob_data_clear() when necessary.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch adds some extra debug logs to L2CAP related code. These are
mainly to help track locking issues but will probably be useful for
debugging other types of issues as well.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that the SMP related key lists are converted to RCU there is nothing
in smp_cmd_sign_info() or smp_cmd_ident_addr_info() that would require
taking the hdev lock (including the smp_distribute_keys call). This
patch removes this unnecessary locking.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch set converts the hdev->identity_resolving_keys list to use
RCU to eliminate the need to use hci_dev_lock/unlock.
An additional change that must be done is to remove use of
CRYPTO_ALG_ASYNC for the hdev-specific AES crypto context. The reason is
that this context is used for matching RPAs and the loop that does the
matching is under the RCU read lock, i.e. is an atomic section which
cannot sleep.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch set converts the hdev->long_term_keys list to use RCU to
eliminate the need to use hci_dev_lock/unlock.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The insufficient authentication/encryption errors indicate to the L2CAP
client that it should try to elevate the security level. Since there
really isn't any exception to this rule it makes sense to fully handle
it on the kernel side instead of pushing the responsibility to user
space.
This patch adds special handling of these two error codes and calls
smp_conn_security() with the elevated security level if necessary.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
So far smp_sufficient_security() has returned false if we're encrypted
with an STK but do have an LTK available. However, for the sake of LE
CoC servers we do want to let the incoming connection through even
though we're only encrypted with the STK.
This patch adds a key preference parameter to smp_sufficient_security()
with two possible values (enum used instead of bool for readability).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
For LE CoC L2CAP servers we don't do security level elevation during the
BT_CONNECT2 state (instead LE CoC simply sends an immediate error
response if the security level isn't high enough). Therefore if we get a
security level change while an LE CoC channel is in the BT_CONNECT2
state we should simply do nothing.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Server channels in BT_LISTEN state should use L2CAP_NESTING_PARENT. This
patch fixes the nesting value for the 6lowpan channel.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There's no reason why all users of L2CAP would need to worry about
initializing chan->nesting to L2CAP_NESTING_NORMAL (which is important
since 0 is the same as NESTING_SMP). This patch moves the initialization
to the common place that's used to create all new channels, i.e. the
l2cap_chan_create() function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The teardown callback for L2CAP channels is problematic in that it is
explicitly called for all types of channels from l2cap_chan_del(),
meaning it's not possible to hard-code a nesting level when taking the
socket lock. The simplest way to have a correct nesting level for the
socket locking is to use the same value as for the chan. This also means
that the other places trying to lock parent sockets need to be update to
use the chan value (since L2CAP_NESTING_PARENT is defined as 2 whereas
SINGLE_DEPTH_NESTING has the value 1).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
By default lockdep considers all L2CAP channels equal. This would mean
that we get warnings if a channel is locked when another one's lock is
tried to be acquired in the same thread. This kind of inter-channel
locking dependencies exist in the form of parent-child channels as well
as any channel wishing to elevate the security by requesting procedures
on the SMP channel.
To eliminate the chance for these lockdep warnings we introduce a
nesting level for each channel and use that when acquiring the channel
lock. For now there exists the earlier mentioned three identified
categories: SMP, "normal" channels and parent channels (i.e. those in
BT_LISTEN state). The nesting level is defined as atomic_t since we need
access to it before the lock is actually acquired.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The mgmt_user_passkey_request and related functions do not do anything
else except read access to hdev->id. This member never changes after the
hdev creation so there is no need to acquire a lock to read it.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Any code calling bt_accept_dequeue() to get a new child socket from a
server socket should use lock_sock_nested to avoid lockdep warnings due
to the parent and child sockets being locked at the same time. The
l2cap_sock_accept() function is already doing this correctly but a
second place calling bt_accept_dequeue() is the code path from
l2cap_sock_teardown_cb() that calls l2cap_sock_cleanup_listen().
This patch fixes the proper nested locking annotation and thereby avoids
the following style of lockdep warning.
[ +0.000224] [ INFO: possible recursive locking detected ]
[ +0.000222] 3.17.0+ #1153 Not tainted
[ +0.000130] ---------------------------------------------
[ +0.000227] l2cap-tester/562 is trying to acquire lock:
[ +0.000210] (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+...}, at: [<c1393f47>] bt_accept_dequeue+0x68/0x11b
[ +0.000467]
but task is already holding lock:
[ +0.000186] (sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP){+.+...}, at: [<c13b949a>] lock_sock+0xa/0xc
[ +0.000421]
other info that might help us debug this:
[ +0.000199] Possible unsafe locking scenario:
[ +0.000117] CPU0
[ +0.000000] ----
[ +0.000000] lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP);
[ +0.000000] lock(sk_lock-AF_BLUETOOTH-BTPROTO_L2CAP);
[ +0.000000]
*** DEADLOCK ***
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When kfree() is all that's needed to free an object protected by RCU
there's a kfree_rcu() convenience function that can be used. This patch
updates the 6lowpan code to use this, thereby eliminating the need for
the separate peer_free() function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch fixes a regression that was introduced by commit
cb77c3ec07. In addition to BT_CONFIG,
BT_CONNECTED is also a state in which we may get a remote name and need
to indicate over mgmt the connection status. This scenario is
particularly likely to happen for incoming connections that do not need
authentication since there the hci_conn state will reach BT_CONNECTED
before the remote name is received.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This fixes the following sparse warning:
net/bluetooth/amp.c:152:53: warning: Variable length array is used.
The warning itself is probably harmless since this kind of usage of
shash_desc is present also in other places in the kernel (there's even a
convenience macro SHASH_DESC_ON_STACK available for defining such stack
variables). However, dynamically allocated versions are also used in
several places of the kernel (e.g. kernel/kexec.c and lib/digsig.c)
which have the benefit of not exhibiting the sparse warning.
Since there are no more sparse warnings in the Bluetooth subsystem after
fixing this one it is now easier to spot whenever new ones might get
introduced by future patches.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch reverts commit:
a7807d73 ("Bluetooth: 6lowpan: Avoid memory leak if memory allocation
fails")
which was wrong suggested by Alexander Aring. The function skb_unshare
run also kfree_skb on failure.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org # 3.18.x
Currently we ensure that the skb is freed on every error path in IPHC
decompression which makes it easy to introduce skb leaks. By centralising
the skb_free into the receive function it makes future decompression routines
easier to maintain. It does come at the expense of ensuring that the skb
passed into the decompression routine must not be copied.
Signed-off-by: Martin Townsend <mtownsend1973@gmail.com>
Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Acked-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Opcodes in switch/case in hci_cmd_status_evt are not sorted
by value. This patch restores proper ordering.
Signed-off-by: Kuba Pawlak <kubax.t.pawlak@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If role switch was rejected by the controller and HCI Event: Command Status
returned with status "Command Disallowed" (0x0C) the flag
HCI_CONN_RSWITCH_PEND remains set. No further role switches are
possible as this flag prevents us from sending any new HCI Switch Role
requests and the only way to clear it is to receive a valid
HCI Event Switch Role.
This patch clears the flag if command was rejected.
2013-01-01 00:03:44.209913 < HCI Command: Switch Role (0x02|0x000b) plen 7
bdaddr BC:C6:DB:C4:6F:79 role 0x00
Role: Master
2013-01-01 00:03:44.210867 > HCI Event: Command Status (0x0f) plen 4
Switch Role (0x02|0x000b) status 0x0c ncmd 1
Error: Command Disallowed
Signed-off-by: Kuba Pawlak <kubax.t.pawlak@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch fixes the following sparse warnings in rfcomm/core.c:
net/bluetooth/rfcomm/core.c:391:16: warning: dubious: x | !y
net/bluetooth/rfcomm/core.c:546:24: warning: dubious: x | !y
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
According to Management Interface API 'Start Discovery' command should
generate a Command Complete event on failure. Currently kernel is
sending Command Status on early errors. This results in userspace
ignoring such event due to invalid size.
bluetoothd[28499]: src/adapter.c:trigger_start_discovery()
bluetoothd[28499]: src/adapter.c:cancel_passive_scanning()
bluetoothd[28499]: src/adapter.c:start_discovery_timeout()
bluetoothd[28499]: src/adapter.c:start_discovery_complete() status 0x0a
bluetoothd[28499]: Wrong size of start discovery return parameters
Reported-by: Jukka Taimisto <jtt@codenomicon.com>
Signed-off-by: Szymon Janc <szymon.janc@tieto.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The debufs entry for the BR/EDR whitelist is confusing since there is
a controller debugfs entry with the name white_list and both are two
different things.
With the BR/EDR whitelist, the actual interface in use is the device
list and thus just include all values from the internal BR/EDR whitelist
in the device_list debugfs entry.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Some Bluetooth drivers require to reset the upper stack. To avoid having
all drivers send HCI Hardware Error events, provide a generic function
to wrap the reset functionality.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
