Verify that the caller-provided sockaddr structure is large enough to
contain the sa_family field, before accessing it in bind() and connect()
handlers of the Bluetooth sockets. Since neither syscall enforces a minimum
size of the corresponding memory region, very short sockaddrs (zero or one
byte long) result in operating on uninitialized memory while referencing
sa_family.
Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Lockdep issues a circular dependency warning when AFS issues an operation
through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem.
The theory lockdep comes up with is as follows:
(1) If the pagefault handler decides it needs to read pages from AFS, it
calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but
creating a call requires the socket lock:
mmap_sem must be taken before sk_lock-AF_RXRPC
(2) afs_open_socket() opens an AF_RXRPC socket and binds it. rxrpc_bind()
binds the underlying UDP socket whilst holding its socket lock.
inet_bind() takes its own socket lock:
sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET
(3) Reading from a TCP socket into a userspace buffer might cause a fault
and thus cause the kernel to take the mmap_sem, but the TCP socket is
locked whilst doing this:
sk_lock-AF_INET must be taken before mmap_sem
However, lockdep's theory is wrong in this instance because it deals only
with lock classes and not individual locks. The AF_INET lock in (2) isn't
really equivalent to the AF_INET lock in (3) as the former deals with a
socket entirely internal to the kernel that never sees userspace. This is
a limitation in the design of lockdep.
Fix the general case by:
(1) Double up all the locking keys used in sockets so that one set are
used if the socket is created by userspace and the other set is used
if the socket is created by the kernel.
(2) Store the kern parameter passed to sk_alloc() in a variable in the
sock struct (sk_kern_sock). This informs sock_lock_init(),
sock_init_data() and sk_clone_lock() as to the lock keys to be used.
Note that the child created by sk_clone_lock() inherits the parent's
kern setting.
(3) Add a 'kern' parameter to ->accept() that is analogous to the one
passed in to ->create() that distinguishes whether kernel_accept() or
sys_accept4() was the caller and can be passed to sk_alloc().
Note that a lot of accept functions merely dequeue an already
allocated socket. I haven't touched these as the new socket already
exists before we get the parameter.
Note also that there are a couple of places where I've made the accepted
socket unconditionally kernel-based:
irda_accept()
rds_rcp_accept_one()
tcp_accept_from_sock()
because they follow a sock_create_kern() and accept off of that.
Whilst creating this, I noticed that lustre and ocfs don't create sockets
through sock_create_kern() and thus they aren't marked as for-kernel,
though they appear to be internal. I wonder if these should do that so
that they use the new set of lock keys.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix up affected files that include this signal functionality via sched.h.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
During an audit for sk_filter(), we found that rx_busy_skb handling
in l2cap_sock_recv_cb() and l2cap_sock_recvmsg() looks not quite as
intended.
The assumption from commit e328140fda ("Bluetooth: Use event-driven
approach for handling ERTM receive buffer") is that errors returned
from sock_queue_rcv_skb() are due to receive buffer shortage. However,
nothing should prevent doing a setsockopt() with SO_ATTACH_FILTER on
the socket, that could drop some of the incoming skbs when handled in
sock_queue_rcv_skb().
In that case sock_queue_rcv_skb() will return with -EPERM, propagated
from sk_filter() and if in L2CAP_MODE_ERTM mode, wrong assumption was
that we failed due to receive buffer being full. From that point onwards,
due to the to-be-dropped skb being held in rx_busy_skb, we cannot make
any forward progress as rx_busy_skb is never cleared from l2cap_sock_recvmsg(),
due to the filter drop verdict over and over coming from sk_filter().
Meanwhile, in l2cap_sock_recv_cb() all new incoming skbs are being
dropped due to rx_busy_skb being occupied.
Instead, just use __sock_queue_rcv_skb() where an error really tells that
there's a receive buffer issue. Split the sk_filter() and enable it for
non-segmented modes at queuing time since at this point in time the skb has
already been through the ERTM state machine and it has been acked, so dropping
is not allowed. Instead, for ERTM and streaming mode, call sk_filter() in
l2cap_data_rcv() so the packet can be dropped before the state machine sees it.
Fixes: e328140fda ("Bluetooth: Use event-driven approach for handling ERTM receive buffer")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When we retrieve imtu value from userspace we should use 16 bit pointer
cast instead of 32 as it's defined that way in headers. Fixes setsockopt
calls on big-endian platforms.
Signed-off-by: Amadeusz Sławiński <amadeusz.slawinski@tieto.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org
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: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel 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: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
There is a L2CAP protocol race between the local peer and
the remote peer demanding disconnection of the L2CAP link.
When L2CAP ERTM is used, l2cap_sock_shutdown() can be called
from userland to disconnect L2CAP. However, there can be a
delay introduced by waiting for ACKs. During this waiting
period, the remote peer may have sent a Disconnection Request.
Therefore, recheck the shutdown status of the socket
after waiting for ACKs because there is no need to do
further processing if the connection has gone.
Signed-off-by: Dean Jenkins <Dean_Jenkins@mentor.com>
Signed-off-by: Harish Jenny K N <harish_kandiga@mentor.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit reorganizes the mutex lock and is now
only protecting l2cap_chan_close(). This is now consistent
with other places where l2cap_chan_close() is called.
If a conn connection exists, call
mutex_lock(&conn->chan_lock) before calling l2cap_chan_close()
to ensure other L2CAP protocol operations do not interfere.
Note that the conn structure has to be protected from being
freed as it is possible for the connection to be disconnected
whilst the locks are not held. This solution allows the mutex
lock to be used even when the connection has just been
disconnected.
This commit also reduces the scope of chan locking.
The only place where chan locking is needed is the call to
l2cap_chan_close(chan, 0) which if necessary closes the channel.
Therefore, move the l2cap_chan_lock(chan) and
l2cap_chan_lock(chan) locking calls to around
l2cap_chan_close(chan, 0).
This allows __l2cap_wait_ack(sk, chan) to be called with no
chan locks being held so L2CAP messaging over the ACL link
can be done unimpaired.
Signed-off-by: Dean Jenkins <Dean_Jenkins@mentor.com>
Signed-off-by: Harish Jenny K N <harish_kandiga@mentor.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
l2cap_sock_shutdown() is designed to only action shutdown
of the channel when shutdown is not already in progress.
Therefore, reorganise the code flow by adding a goto
to jump to the end of function handling when shutdown is
already being actioned. This removes one level of code
indentation and make the code more readable.
Signed-off-by: Dean Jenkins <Dean_Jenkins@mentor.com>
Signed-off-by: Harish Jenny K N <harish_kandiga@mentor.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Add a timeout to prevent the do while loop running in an
infinite loop. This ensures that the channel will be
instructed to close within 10 seconds so prevents
l2cap_sock_shutdown() getting stuck forever.
Returns -ENOLINK when the timeout is reached. The channel
will be subequently closed and not all data will be ACK'ed.
Signed-off-by: Dean Jenkins <Dean_Jenkins@mentor.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Use msecs_to_jiffies() instead of using HZ so that it
is easier to specify the time in milliseconds.
Also add a #define L2CAP_WAIT_ACK_POLL_PERIOD to specify the 200ms
polling period so that it is defined in a single place.
Signed-off-by: Dean Jenkins <Dean_Jenkins@mentor.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Add helpful BT_DBG debug to l2cap_sock_shutdown()
and __l2cap_wait_ack() so that the code flow can
be analysed.
Signed-off-by: Dean Jenkins <Dean_Jenkins@mentor.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Use chan->state instead of chan->conn because waiting
for ACK's is only possible in the BT_CONNECTED state.
Also avoids reference to the conn structure so makes
locking easier.
Only call __l2cap_wait_ack() when the needed condition
of chan->unacked_frames > 0 && chan->state == BT_CONNECTED
is true and convert the while loop to a do while loop.
__l2cap_wait_ack() change the function prototype to
pass in the chan variable as chan is already available
in the calling function l2cap_sock_shutdown(). Avoids
locking issues.
Signed-off-by: Dean Jenkins <Dean_Jenkins@mentor.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
During execution of l2cap_sock_shutdown() which might
sleep, the sk and chan structures can be in an unlocked
condition which potentially allows the structures to be
freed by other running threads. Therefore, there is a
possibility of a malfunction or memory reuse after being
freed.
Keep the sk and chan structures alive during the
execution of l2cap_sock_shutdown() by using their
respective hold and put functions. This allows the structures
to be freeable at the end of l2cap_sock_shutdown().
Signed-off-by: Kautuk Consul <Kautuk_Consul@mentor.com>
Signed-off-by: Dean Jenkins <Dean_Jenkins@mentor.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
In preparation for changing how struct net is refcounted
on kernel sockets pass the knowledge that we are creating
a kernel socket from sock_create_kern through to sk_alloc.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We're getting very close to the maximum possible size of bt_skb_cb. To
prepare to shrink the struct with the help of a union this patch moves
all L2CAP related variables into the l2cap_ctrl struct. To later add
other 'ctrl' structs the L2CAP one is renamed simple 'l2cap' instead
of 'control'.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
After TIPC doesn't depend on iocb argument in its internal
implementations of sendmsg() and recvmsg() hooks defined in proto
structure, no any user is using iocb argument in them at all now.
Then we can drop the redundant iocb argument completely from kinds of
implementations of both sendmsg() and recvmsg() in the entire
networking stack.
Cc: Christoph Hellwig <hch@lst.de>
Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
l2cap/rfcomm/sco_sock_accept() are wait loops which may acquire
sleeping locks. Since both wait loops and sleeping locks use
task_struct.state to sleep and wake, the nested sleeping locks
destroy the wait loop state.
Use the newly-minted wait_woken() and DEFINE_WAIT_FUNC() for the
wait loop. DEFINE_WAIT_FUNC() allows an alternate wake function
to be specified; in this case, the predefined scheduler function,
woken_wake_function(). This wait construct ensures wakeups will
not be missed without requiring the wait loop to set the
task state before condition evaluation. How this works:
CPU 0 | CPU 1
|
| is <condition> set?
| no
set <condition> |
|
wake_up_interruptible |
woken_wake_function |
set WQ_FLAG_WOKEN |
try_to_wake_up |
| wait_woken
| set TASK_INTERRUPTIBLE
| WQ_FLAG_WOKEN? yes
| set TASK_RUNNING
|
| - loop -
|
| is <condition> set?
| yes - exit wait loop
Fixes "do not call blocking ops when !TASK_RUNNING" warnings
in l2cap_sock_accept(), rfcomm_sock_accept() and sco_sock_accept().
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This adds an extra check for ensuring that the size of sockaddr_l2
does not grow larger than sockaddr.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Just use copy_from_iter(). That's what this method is trying to do
in all cases, in a very convoluted fashion.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
it'll die soon enough - now that kvec-backed iov_iter works regardless
of set_fs(), both instances will become copy_from_iter() as soon as
we introduce ->msg_iter...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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>
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>
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>
Now that SMP has been converted to use fixed channels we've got a bit of
a problem with the hci_conn reference counting. So far the L2CAP code
has kept a reference for each L2CAP channel that was notified of the
connection. With SMP however this would mean that the connection is
never dropped even though there are no other users of it. Furthermore,
SMP already does its own hci_conn reference counting internally,
starting from a security or pairing request and ending with the key
distribution.
This patch makes L2CAP fixed channels default to the L2CAP core not
keeping a hci_conn reference for them. A new FLAG_HOLD_HCI_CONN flag is
added so that L2CAP users can declare an exception to this rule and hold
a reference even for their fixed channels. One such exception is the
L2CAP socket layer which does want a reference for each socket (e.g. an
ATT socket which uses a fixed channel).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The l2cap_add_scid function is used for registering a fixed L2CAP
channel. Instead of having separate initialization of the channel type
and outgoing MTU in l2cap_sock.c it's more intuitive to do these things
in the l2cap_add_scid function itself (and thereby make the
functionality available to other users besides l2cap_sock.c).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The LE ATT socket uses a special trick where it temporarily sets
BT_CONFIG state for the duration of a security level elevation. In order
to not require special hacks for going back to BT_CONNECTED state in the
l2cap_core.c code the most reasonable place to resume the state is the
resume callback. This patch adds a new flag to track the pending
security level change and ensures that the state is set back to
BT_CONNECTED in the resume callback in case the flag is set.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The EOPNOTSUPP and ENOTSUPP errors are very similar in meaning, but
ENOTSUPP is a fairly new addition to POSIX. Not all libc versions know
about the value the kernel uses for ENOTSUPP so it's better to use
EOPNOTSUPP to ensure understandable error messages.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
We're interested in whether an authentication request is because of a
remote or local action. So far hci_conn_security() has been used both
for incoming and outgoing actions (e.g. RFCOMM or L2CAP connect
requests) so without some modifications it cannot know which peer is
responsible for requesting authentication.
This patch adds a new "bool initiator" parameter to hci_conn_security()
to indicate which side is responsible for the request and updates the
current users to pass this information correspondingly.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
If the current process is exiting, lingering on socket close will make
it unkillable, so we should avoid it.
Reproducer:
#include <sys/types.h>
#include <sys/socket.h>
#define BTPROTO_L2CAP 0
#define BTPROTO_SCO 2
#define BTPROTO_RFCOMM 3
int main()
{
int fd;
struct linger ling;
fd = socket(PF_BLUETOOTH, SOCK_STREAM, BTPROTO_RFCOMM);
//or: fd = socket(PF_BLUETOOTH, SOCK_DGRAM, BTPROTO_L2CAP);
//or: fd = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_SCO);
ling.l_onoff = 1;
ling.l_linger = 1000000000;
setsockopt(fd, SOL_SOCKET, SO_LINGER, &ling, sizeof(ling));
return 0;
}
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org
We have all the necessary remote information for getpeername() when we
are in the BT_CONFIG state so this should be allowed. This is
particularly important for LE sockets where changing the security level
will temporarily move the socket into BT_CONFIG state.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The highly optimized TX path for L2CAP channels and its fragmentation
within the HCI ACL packets requires to copy data from user provided
IO vectors and also kernel provided memory buffers.
This patch allows channel clients to provide a memcpy_fromiovec callback
to keep this optimized behavior, but adapt it to kernel vs user memory
for the TX path. For all kernel internal L2CAP channels, a default
implementation is provided that can be referenced.
In case of A2MP, this fixes a long-standing issue with wrongly accessing
kernel memory as user memory.
This patch originally by Marcel Holtmann.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When allocating the L2CAP SKB for transmission, provide the upper layers
with a clear distinction on what is the header and what is the body
portion of the SKB.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The SKB for L2CAP sockets are all allocated in a central callback
in the socket support. Instead of having to pass around the socket
priority all the time, assign it to skb->priority when actually
allocating the SKB.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
The struct l2cap_ops field should not allow any modifications and thus
it is better declared as const.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Kernel supports SMP Security Request so don't block increasing security
when we are slave.
Signed-off-by: Marcin Kraglak <marcin.kraglak@tieto.com>
Acked-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org
-[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>
Cc: stable@vger.kernel.org
Several spots in the kernel perform a sequence like:
skb_queue_tail(&sk->s_receive_queue, skb);
sk->sk_data_ready(sk, skb->len);
But at the moment we place the SKB onto the socket receive queue it
can be consumed and freed up. So this skb->len access is potentially
to freed up memory.
Furthermore, the skb->len can be modified by the consumer so it is
possible that the value isn't accurate.
And finally, no actual implementation of this callback actually uses
the length argument. And since nobody actually cared about it's
value, lots of call sites pass arbitrary values in such as '0' and
even '1'.
So just remove the length argument from the callback, that way there
is no confusion whatsoever and all of these use-after-free cases get
fixed as a side effect.
Based upon a patch by Eric Dumazet and his suggestion to audit this
issue tree-wide.
Signed-off-by: David S. Miller <davem@davemloft.net>
We should let user space request the peer address also in the pending
connect states, i.e. BT_CONNECT and BT_CONNECT2. There is existing user
space code that tries to do this and will fail without extending the set
of allowed states for the peer address information.
This patch adds the two states to the allowed ones in the L2CAP and
RFCOMM sock_getname functions, thereby preventing ENOTCONN from being
returned.
Reported-by: Andrzej Kaczmarek <andrzej.kaczmarek@tieto.com>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Tested-by: Andrzej Kaczmarek <andrzej.kaczmarek@tieto.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The use of __constant_<foo> has been unnecessary for quite awhile now.
Make these uses consistent with the rest of the kernel.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Now that the LE L2CAP Connection Oriented Channel support has undergone a
decent amount of testing we can make it officially supported. This patch
removes the enable_lecoc module parameter which was previously needed to
enable support for LE L2CAP CoC.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The l2cap_chan->psm value is always set to a valid value for a
connection oriented channel. The l2cap_chan->sport is used for tracking
local PSM allocations but will not always have a proper value, such as
with connected sockets derived from a listening socket. This patch fixes
the sock_getname callback to always use chan->psm when returning address
information.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When we're not connected the peer address information is undefined. This
patch fixes the remote address getting to return a proper error in case
the state is anything else than BT_CONNECTED.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Fixed channels have the same source and destination CID. Ensure that the
values get properly initialized when receiving incoming connections and
deriving values from the parent socket.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The BT_SECURITY option should also be allowed for fixed channels, so
punch the appropriate hole for it when checking for the channel type.
The main user of fixed CID user space sockets is right now ATT (which is
broken without this patch).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
