commit 8a96f3cd22 upstream.
-[0x01 Introduction
We have found a programming error causing a deadlock in Bluetooth subsystem
of Linux kernel. The problem is caused by missing release_sock() call when
L2CAP connection creation fails due full accept queue.
The issue can be reproduced with 3.15-rc5 kernel and is also present in
earlier kernels.
-[0x02 Details
The problem occurs when multiple L2CAP connections are created to a PSM which
contains listening socket (like SDP) and left pending, for example,
configuration (the underlying ACL link is not disconnected between
connections).
When L2CAP connection request is received and listening socket is found the
l2cap_sock_new_connection_cb() function (net/bluetooth/l2cap_sock.c) is called.
This function locks the 'parent' socket and then checks if the accept queue
is full.
1178 lock_sock(parent);
1179
1180 /* Check for backlog size */
1181 if (sk_acceptq_is_full(parent)) {
1182 BT_DBG("backlog full %d", parent->sk_ack_backlog);
1183 return NULL;
1184 }
If case the accept queue is full NULL is returned, but the 'parent' socket
is not released. Thus when next L2CAP connection request is received the code
blocks on lock_sock() since the parent is still locked.
Also note that for connections already established and waiting for
configuration to complete a timeout will occur and l2cap_chan_timeout()
(net/bluetooth/l2cap_core.c) will be called. All threads calling this
function will also be blocked waiting for the channel mutex since the thread
which is waiting on lock_sock() alread holds the channel mutex.
We were able to reproduce this by sending continuously L2CAP connection
request followed by disconnection request containing invalid CID. This left
the created connections pending configuration.
After the deadlock occurs it is impossible to kill bluetoothd, btmon will not
get any more data etc. requiring reboot to recover.
-[0x03 Fix
Releasing the 'parent' socket when l2cap_sock_new_connection_cb() returns NULL
seems to fix the issue.
Signed-off-by: Jukka Taimisto <jtt@codenomicon.com>
Reported-by: Tommi Mäkilä <tmakila@codenomicon.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is a follow-up patch to f3d3342602 ("net: rework recvmsg
handler msg_name and msg_namelen logic").
DECLARE_SOCKADDR validates that the structure we use for writing the
name information to is not larger than the buffer which is reserved
for msg->msg_name (which is 128 bytes). Also use DECLARE_SOCKADDR
consistently in sendmsg code paths.
Signed-off-by: Steffen Hurrle <steffen@hurrle.net>
Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
L2CAP RAW sockets can be used for things which do not involve
establishing actual connection oriented L2CAP channels. One example of
such usage is the l2ping tool. The default security level for L2CAP
sockets is LOW, which implies that for SSP based connection
authentication is still requested (although with no MITM requirement),
which is not what we want (or need) for things like l2ping. Therefore,
default to one lower level, i.e. BT_SECURITY_SDP, for L2CAP RAW sockets
in order not to trigger unwanted authentication requests.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The values in l2cap_chan that are used for actually transmitting data
only need to be initialized right after we've received an L2CAP Connect
Request or just before we send one. The only thing that we need to
initialize though bind() and connect() is the chan->mode value. This way
all other initializations can be done in the l2cap_le_flowctl_init
function (which now becomes private to l2cap_core.c) and the
l2cap_le_flowctl_start function can be completely removed.
Also, since the l2cap_sock_init function initializes the imtu and omtu
to adequate values these do not need to be part of l2cap_le_flowctl_init.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
LE PSM values have different ranges than those for BR/EDR. The valid
ranges for fixed, SIG assigned values is 0x0001-0x007f and for dynamic
PSM values 0x0080-0x00ff. We need to ensure that bind() and connect()
calls conform to these ranges when operating on LE CoC sockets.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Setting the BT_SK_SUSPEND socket flag from the L2CAP core is causing a
dependency on the socket. So instead of doing that, use a channel
callback into the socket handling to suspend.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch adds new socket options for LE sockets since the existing
L2CAP_OPTIONS socket option is not usable for LE. For now, the new
socket options also require LE CoC support to be explicitly enabled to
leave some playroom in case something needs to be changed in a backwards
incompatible way.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Most of the values in L2CAP_OPTIONS are not applicable for LE and those
that are have different semantics. It makes therefore sense to
completely block this socket option for LE and add (in a separate patch)
a new socket option for tweaking the values that do make sense (mainly
the send and receive MTU). Legacy user space ATT code still depends on
getsockopt for L2CAP_OPTIONS though so we need to plug a hole for that
for backwards compatibility.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch adds tracking of L2CAP connection oriented channel local and
remote credits to struct l2cap_chan and ensures that connect requests
and responses contain the right values.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The LE connection oriented channels have their own mode with its own
data transfer rules. In order to implement this properly we need to
distinguish L2CAP channels operating in this mode from other modes.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Along with the L2CAP Connection Oriented Channels features it is now
allowed to use both custom fixed CIDs as well as PSM based (connection
oriented connections). Since the support for this (with the subsequent
patches) is still on an experimental stage, add a module parameter to
enable it.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There is no access to chan->sk in L2CAP core now. This change marks the
end of the task of splitting L2CAP between Core and Socket, thus sk is now
gone from struct l2cap_chan.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Adding the channel to the skb private data makes possible to us know which
channel the skb we have came from.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The parent socket is not used inside the L2CAP core anymore. We only lock
it to indirect access through the new_connection() callback. The hold of
the socket lock was moved to the new_connection() callback.
Inside L2CAP core the channel lock is now used in l2cap_le_conn_ready()
and l2cap_conn_ready() to protect the execution of these two functions
during the handling of new incoming connections.
This change remove the socket lock usage from L2CAP core while keeping
the code safe against race conditions.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In both places that we use the defer callback the socket lock is held for
a indirect sk access inside __l2cap_change_state() and chan->ops->defer(),
all the rest of the code between lock_sock() and release_sock() is
already protected by the channel lock and won't be affected by this
change.
We now use l2cap_change_state(), the locked version of the change state
function, and the defer callback does the locking itself now. This does
not affect other uses of the defer callback.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In the process of removing socket usage from L2CAP we now access the L2CAP
socket from the data member of struct l2cap_chan. For the L2CAP socket
user the data member points to the L2CAP socket.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Old user space versions bind the Attribute Protocol socket to
BDADDR_BREDR when they should be using BDADDR_LE_PUBLIC or
BDADDR_LE_RANDOM. The kernel recently introduced stricter checks on the
socket parameters but we need to punch this hole for old user space
versions to keep them working.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The L2CAP socket parameter for CID are actually provided in little
endian. So convert our constants into little endian before comparing
them.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Right now we do not allow user space to use connection oriented channels
on LE, and the only CID that can be used is the Attribute Protocol one.
These restrictions went away together with the recent refactoring of the
L2CAP code, but this patch puts them back to their appropriate places.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The wait_ack code has a heavy dependency on the socket data structures
and, as of now, it won't be worthless change it to use non-socket
structures as the only user of such feature is a socket.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We need to remove all direct access of struct sock from L2CAP core.
This change is pretty simple and just add a new L2CAP channel callback to
do the work in the L2CAP socket side.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
As part of the work to remove struct sock from l2cap_core.c and make it
more generic we remove in this commit the direct access to sk->sk_sndtimeo
member. This objective of this change is purely remove sk usage from
l2cap_core.c
Now we have a new l2cap ops to get the current value of sk->sndtimeo. A
l2cap_chan_no_get_sndtimeo was added for users of L2CAP that doesn't need
to set a timeout.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Instead of creating an new function pointer to report errors we are just
reusing state_change for that and there is a simple reason for this, one
place in the l2cap_core.c code needs, in a locked sk, set both the sk_state
and sk_err. If we create two different functions for this we would need to
release the lock between the two operation putting the socket in non
desired state.
The change is transparent to the l2cap_core.c code, user that only needs
to set the state won't need any modification.
This is another step of an ongoing work to make l2cap_core.c totally
independent from l2cap's struct sock.
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If a socket was bound to an address type other than BR/EDR (such as LE)
we should reject trying to connect it to a BR/EDR address. The same
applies for binding to BR/EDR and trying to connect to non-BR/EDR.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We need to verify that the bdaddr type passed to connect() and bind() is
within the set of valid values. If it is not we need to cleanly fail
with EINVAL.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Clearing the BT_SK_SUSPEND socket flag from the L2CAP core is causing
a dependency on the socket. So intead of doing that, use a channel
callback into the socket handling to resume.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The L2CAP core should not look into the socket flags to figure out the
setting of defer setup. So introduce a L2CAP channel flag that mirrors
the socket flag.
Since the defer setup option is only set in one place this becomes a
really easy thing to do.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The L2CAP connectionless channels use SOCK_DGRAM and recvmsg() and need
to receive the remote BD_ADDR and PSM information via msg_name from
the recvmsg() system call.
So in case the L2CAP socket is for connectionless channels, provide
a msg_name callback that can update the data. Also store the remote
BD_ADDR and PSM in the skb so it can be extracted later on.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
There are few places where it makes sense to use l2cap_pi(sk) directly
instead of assigning it to temporary structure.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The L2CAP sockets can use BR/EDR public, LE public and LE random
addresses for various combinations of source and destination
devices. So make sure that getsockname(), getpeername() and
accept() return the correct address type.
For this the address type of the source and destination is stored
with the L2CAP channel information. The stored address type is
not the one specific for the HCI protocol. It is the address
type used for the L2CAP sockets and the management interface.
The underlying HCI connections store the HCI address type. If
needed, it gets converted to the socket address type.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
With the effort of abstracting the L2CAP socket from the underlying
L2CAP channel it is important to store the source and destination
address information directly in the L2CAP channel structure.
Direct access to the HCI connection address information is not
possible since they might not be avaiable at L2CAP channel
creation time. The address information will be updated when
the underlying BR/EDR or LE connection status changes.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The PSM 0x0021 is dedicated to the 3D profile and has permission to
use security mode 4 level 0 for L2CAP connectionless unicast data
transfers.
When establishing a L2CAP connectionless channel on PSM 0x0021, it
will no longer force Secure Simple Pairing.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The exception for certain PSM channels when it comes to security
mode 4 level 0 should only be checked when actually a connection
oriented channel is established.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The smp.h header file is only used internally by the bluetooth.ko
module and is not a public API. So make it local to the core
Bluetooth module.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Sparse points out three places where variables are shadowed,
rename two of the variables and remove the duplicate third.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Hiding the Bluetooth high speed support behind a module parameter is
not really useful. This can be enabled and disabled at runtime via
the management interface. This also has the advantage that this can
now be changed per controller and not just global.
This patch removes the module parameter and exposes the high speed
setting of the management interface to all controllers.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This patch cleans up the locking login in l2cap_sock_recvmsg by pairing
up each lock_sock call with a release_sock call. The function already
has a "done" label that handles releasing the socket and returning from
the function so the fix is rather simple.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
In the case of blocking sockets we should not proceed with sendmsg() if
the socket has the BT_SK_SUSPEND flag set. So far the code was only
ensuring that POLLOUT doesn't get set for non-blocking sockets using
poll() but there was no code in place to ensure that blocking sockets do
the right thing when writing to them.
This patch adds a new bt_sock_wait_ready helper function to sleep in the
sendmsg call if the BT_SK_SUSPEND flag is set, and wake up as soon as it
is unset. It also updates the L2CAP and RFCOMM sendmsg callbacks to take
advantage of this new helper function.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
In future Core Specification versions the ATT CID will be just one of
many possible CIDs that can be used for data transfer. Therefore, it
makes sense to rename the define for the ATT CID to something less
ambigous.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Pull VFS updates from Al Viro,
Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).
7kloc removed.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
don't bother with deferred freeing of fdtables
proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
proc: Make the PROC_I() and PDE() macros internal to procfs
proc: Supply a function to remove a proc entry by PDE
take cgroup_open() and cpuset_open() to fs/proc/base.c
ppc: Clean up scanlog
ppc: Clean up rtas_flash driver somewhat
hostap: proc: Use remove_proc_subtree()
drm: proc: Use remove_proc_subtree()
drm: proc: Use minor->index to label things, not PDE->name
drm: Constify drm_proc_list[]
zoran: Don't print proc_dir_entry data in debug
reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
proc: Supply an accessor for getting the data from a PDE's parent
airo: Use remove_proc_subtree()
rtl8192u: Don't need to save device proc dir PDE
rtl8187se: Use a dir under /proc/net/r8180/
proc: Add proc_mkdir_data()
proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
proc: Move PDE_NET() to fs/proc/proc_net.c
...
We need to verify that the given sockets actually are l2cap sockets. If
they aren't, we are not supposed to access bt_sk(sock) and we shouldn't
start the session if the offsets turn out to be valid local BT addresses.
That is, if someone passes a TCP socket to HIDCONNADD, then we access some
random offset in the TCP socket (which isn't even guaranteed to be valid).
Fix this by checking that the socket is an l2cap socket.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
After we successfully registered a socket via bt_sock_register() there is
no reason to ever check the return code of bt_sock_unregister(). If
bt_sock_unregister() fails, it means the socket _is_ already unregistered
so we have what we want, don't we?
Also, to get bt_sock_unregister() to fail, another part of the kernel has
to unregister _our_ socket. This is sooo _wrong_ that it will break way
earlier than when we unregister our socket.
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Channel moves are triggered by changes to the BT_CHANNEL_POLICY
sockopt when an ERTM or streaming-mode channel is connected.
Moves are only started if enable_hs is true.
Signed-off-by: Mat Martineau <mathewm@codeaurora.org>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
When DEFER_SETUP is set defer() will trigger an authorization
request to the userspace.
l2cap_chan_no_defer() is meant to be used when one does not want to
support DEFER_SETUP (A2MP for example).
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
This is part of the move the parent socket usage to l2cap_sock.c
The change is safe when it comes to locking, bt_accept_enqueue() is still
protected by the parent socket lock inside the
l2cap_sock_new_connection_cb() code.
Acked-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Vladimir Davydov
Marcin Kraglak
Jukka Taimisto
Steffen Hurrle
Johan Hedberg
Gustavo Padovan
Marcel Holtmann
Johannes Berg
Linus Torvalds
Al Viro
David Herrmann
Mat Martineau
John W. Linville