linux-stable.git/net/bluetooth, branch v4.9.91

Bluetooth: 6lowpan: fix delay work init in add_peer_chan()

2018-03-22T08:17:52+00:00

[ Upstream commit d2891c4d071d807f01cc911dc42a68f4568d65cf ]

When adding 6lowpan devices very rapidly we sometimes see a crash:
[23122.306615] CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.9.0-43-arm64 #1 Debian 4.9.9.linaro.43-1
[23122.315400] Hardware name: HiKey Development Board (DT)
[23122.320623] task: ffff800075443080 task.stack: ffff800075484000
[23122.326551] PC is at expire_timers+0x70/0x150
[23122.330907] LR is at run_timer_softirq+0xa0/0x1a0
[23122.335616] pc : [] lr : [] pstate: 600001c5

This was due to add_peer_chan() unconditionally initializing the
lowpan_btle_dev->notify_peers delayed work structure, even if the
lowpan_btle_dev passed into add_peer_chan() had previously been
initialized.

Normally, this would go unnoticed as the delayed work timer is set for
100 msec, however when calling add_peer_chan() faster than 100 msec it
clears out a previously queued delay work causing the crash above.

To fix this, let add_peer_chan() know when a new lowpan_btle_dev is passed
in so that it only performs the delay work initialization when needed.

Signed-off-by: Michael Scott 
Acked-by: Jukka Rissanen 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: Avoid bt_accept_unlink() double unlinking

2018-03-22T08:17:52+00:00

[ Upstream commit 27bfbc21a0c0f711fa5382de026c7c0700c9ea28 ]

There is a race condition between a thread calling bt_accept_dequeue()
and a different thread calling bt_accept_unlink(). Protection against
concurrency is implemented using sk locking. However, sk locking causes
serialisation of the bt_accept_dequeue() and bt_accept_unlink() threads.
This serialisation can cause bt_accept_dequeue() to obtain the sk from the
parent list but becomes blocked waiting for the sk lock held by the
bt_accept_unlink() thread. bt_accept_unlink() unlinks sk and this thread
releases the sk lock unblocking bt_accept_dequeue() which potentially runs
bt_accept_unlink() again on the same sk causing a crash. The attempt to
double unlink the same sk from the parent list can cause a NULL pointer
dereference crash due to bt_sk(sk)->parent becoming NULL on the first
unlink, followed by the second unlink trying to execute
bt_sk(sk)->parent->sk_ack_backlog-- in bt_accept_unlink() which crashes.

When sk is in the parent list, bt_sk(sk)->parent will be not be NULL.
When sk is removed from the parent list, bt_sk(sk)->parent is set to
NULL. Therefore, add a defensive check for bt_sk(sk)->parent not being
NULL to ensure that sk is still in the parent list after the sk lock has
been taken in bt_accept_dequeue(). If bt_sk(sk)->parent is detected as
being NULL then restart the loop so that the loop variables are refreshed
to use the latest values. This is necessary as list_for_each_entry_safe()
is not thread safe so causing a risk of an infinite loop occurring as sk
could point to itself.

In addition, in bt_accept_dequeue() increase the sk reference count to
protect against early freeing of sk. Early freeing can be possible if the
bt_accept_unlink() thread calls l2cap_sock_kill() or rfcomm_sock_kill()
functions before bt_accept_dequeue() gets the sk lock.

For test purposes, the probability of failure can be increased by putting
a msleep of 1 second in bt_accept_dequeue() between getting the sk and
waiting for the sk lock. This exposes the fact that the loop
list_for_each_entry_safe(p, n, &bt_sk(parent)->accept_q) is not safe from
threads that unlink sk from the list in parallel with the loop which can
cause sk to become stale within the loop.

Signed-off-by: Dean Jenkins 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: Prevent stack info leak from the EFS element.

2018-01-17T08:38:56+00:00

commit 06e7e776ca4d36547e503279aeff996cbb292c16 upstream.

In the function l2cap_parse_conf_rsp and in the function
l2cap_parse_conf_req the following variable is declared without
initialization:

struct l2cap_conf_efs efs;

In addition, when parsing input configuration parameters in both of
these functions, the switch case for handling EFS elements may skip the
memcpy call that will write to the efs variable:

...
case L2CAP_CONF_EFS:
if (olen == sizeof(efs))
memcpy(&efs, (void *)val, olen);
...

The olen in the above if is attacker controlled, and regardless of that
if, in both of these functions the efs variable would eventually be
added to the outgoing configuration request that is being built:

l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs), (unsigned long) &efs);

So by sending a configuration request, or response, that contains an
L2CAP_CONF_EFS element, but with an element length that is not
sizeof(efs) - the memcpy to the uninitialized efs variable can be
avoided, and the uninitialized variable would be returned to the
attacker (16 bytes).

This issue has been assigned CVE-2017-1000410

Cc: Marcel Holtmann 
Cc: Gustavo Padovan 
Cc: Johan Hedberg 
Signed-off-by: Ben Seri 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: Properly check L2CAP config option output buffer length

2017-09-13T21:13:36+00:00

commit e860d2c904d1a9f38a24eb44c9f34b8f915a6ea3 upstream.

Validate the output buffer length for L2CAP config requests and responses
to avoid overflowing the stack buffer used for building the option blocks.

Signed-off-by: Ben Seri 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: bnep: fix possible might sleep error in bnep_session

2017-08-30T08:21:52+00:00

commit 25717382c1dd0ddced2059053e3ca5088665f7a5 upstream.

It looks like bnep_session has same pattern as the issue reported in
old rfcomm:

	while (1) {
		set_current_state(TASK_INTERRUPTIBLE);
		if (condition)
			break;
		// may call might_sleep here
		schedule();
	}
	__set_current_state(TASK_RUNNING);

Which fixed at:
	dfb2fae Bluetooth: Fix nested sleeps

So let's fix it at the same way, also follow the suggestion of:
https://lwn.net/Articles/628628/

Signed-off-by: Jeffy Chen 
Reviewed-by: Brian Norris 
Reviewed-by: AL Yu-Chen Cho 
Signed-off-by: Marcel Holtmann 
Cc: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: cmtp: fix possible might sleep error in cmtp_session

2017-08-30T08:21:52+00:00

commit f06d977309d09253c744e54e75c5295ecc52b7b4 upstream.

It looks like cmtp_session has same pattern as the issue reported in
old rfcomm:

	while (1) {
		set_current_state(TASK_INTERRUPTIBLE);
		if (condition)
			break;
		// may call might_sleep here
		schedule();
	}
	__set_current_state(TASK_RUNNING);

Which fixed at:
	dfb2fae Bluetooth: Fix nested sleeps

So let's fix it at the same way, also follow the suggestion of:
https://lwn.net/Articles/628628/

Signed-off-by: Jeffy Chen 
Reviewed-by: Brian Norris 
Reviewed-by: AL Yu-Chen Cho 
Signed-off-by: Marcel Holtmann 
Cc: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: hidp: fix possible might sleep error in hidp_session_thread

2017-08-30T08:21:52+00:00

commit 5da8e47d849d3d37b14129f038782a095b9ad049 upstream.

It looks like hidp_session_thread has same pattern as the issue reported in
old rfcomm:

	while (1) {
		set_current_state(TASK_INTERRUPTIBLE);
		if (condition)
			break;
		// may call might_sleep here
		schedule();
	}
	__set_current_state(TASK_RUNNING);

Which fixed at:
	dfb2fae Bluetooth: Fix nested sleeps

So let's fix it at the same way, also follow the suggestion of:
https://lwn.net/Articles/628628/

Signed-off-by: Jeffy Chen 
Tested-by: AL Yu-Chen Cho 
Tested-by: Rohit Vaswani 
Signed-off-by: Marcel Holtmann 
Cc: Jiri Slaby 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: use constant time memory comparison for secret values

2017-07-27T22:07:58+00:00

commit 329d82309824ff1082dc4a91a5bbed8c3bec1580 upstream.

This file is filled with complex cryptography. Thus, the comparisons of
MACs and secret keys and curve points and so forth should not add timing
attacks, which could either result in a direct forgery, or, given the
complexity, some other type of attack.

Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: Fix user channel for 32bit userspace on 64bit kernel

2017-05-20T12:28:41+00:00

commit ab89f0bdd63a3721f7cd3f064f39fc4ac7ca14d4 upstream.

Running 32bit userspace on 64bit kernel results in MSG_CMSG_COMPAT being
defined as 0x80000000. This results in sendmsg failure if used from 32bit
userspace running on 64bit kernel. Fix this by accounting for MSG_CMSG_COMPAT
in flags check in hci_sock_sendmsg.

Signed-off-by: Szymon Janc 
Signed-off-by: Marko Kiiskila 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: Fix using the correct source address type

2016-11-22T21:50:46+00:00

The hci_get_route() API is used to look up local HCI devices, however
so far it has been incapable of dealing with anything else than the
public address of HCI devices. This completely breaks with LE-only HCI
devices that do not come with a public address, but use a static
random address instead.

This patch exteds the hci_get_route() API with a src_type parameter
that's used for comparing with the right address of each HCI device.

Signed-off-by: Johan Hedberg 
Signed-off-by: Marcel Holtmann