linux-stable.git/net/bluetooth, branch v4.4.293

Bluetooth: fix use-after-free error in lock_sock_nested()

2021-11-26T10:58:36+00:00

[ Upstream commit 1bff51ea59a9afb67d2dd78518ab0582a54a472c ]

use-after-free error in lock_sock_nested is reported:

[  179.140137][ T3731] =====================================================
[  179.142675][ T3731] BUG: KMSAN: use-after-free in lock_sock_nested+0x280/0x2c0
[  179.145494][ T3731] CPU: 4 PID: 3731 Comm: kworker/4:2 Not tainted 5.12.0-rc6+ #54
[  179.148432][ T3731] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
[  179.151806][ T3731] Workqueue: events l2cap_chan_timeout
[  179.152730][ T3731] Call Trace:
[  179.153301][ T3731]  dump_stack+0x24c/0x2e0
[  179.154063][ T3731]  kmsan_report+0xfb/0x1e0
[  179.154855][ T3731]  __msan_warning+0x5c/0xa0
[  179.155579][ T3731]  lock_sock_nested+0x280/0x2c0
[  179.156436][ T3731]  ? kmsan_get_metadata+0x116/0x180
[  179.157257][ T3731]  l2cap_sock_teardown_cb+0xb8/0x890
[  179.158154][ T3731]  ? __msan_metadata_ptr_for_load_8+0x10/0x20
[  179.159141][ T3731]  ? kmsan_get_metadata+0x116/0x180
[  179.159994][ T3731]  ? kmsan_get_shadow_origin_ptr+0x84/0xb0
[  179.160959][ T3731]  ? l2cap_sock_recv_cb+0x420/0x420
[  179.161834][ T3731]  l2cap_chan_del+0x3e1/0x1d50
[  179.162608][ T3731]  ? kmsan_get_metadata+0x116/0x180
[  179.163435][ T3731]  ? kmsan_get_shadow_origin_ptr+0x84/0xb0
[  179.164406][ T3731]  l2cap_chan_close+0xeea/0x1050
[  179.165189][ T3731]  ? kmsan_internal_unpoison_shadow+0x42/0x70
[  179.166180][ T3731]  l2cap_chan_timeout+0x1da/0x590
[  179.167066][ T3731]  ? __msan_metadata_ptr_for_load_8+0x10/0x20
[  179.168023][ T3731]  ? l2cap_chan_create+0x560/0x560
[  179.168818][ T3731]  process_one_work+0x121d/0x1ff0
[  179.169598][ T3731]  worker_thread+0x121b/0x2370
[  179.170346][ T3731]  kthread+0x4ef/0x610
[  179.171010][ T3731]  ? process_one_work+0x1ff0/0x1ff0
[  179.171828][ T3731]  ? kthread_blkcg+0x110/0x110
[  179.172587][ T3731]  ret_from_fork+0x1f/0x30
[  179.173348][ T3731]
[  179.173752][ T3731] Uninit was created at:
[  179.174409][ T3731]  kmsan_internal_poison_shadow+0x5c/0xf0
[  179.175373][ T3731]  kmsan_slab_free+0x76/0xc0
[  179.176060][ T3731]  kfree+0x3a5/0x1180
[  179.176664][ T3731]  __sk_destruct+0x8af/0xb80
[  179.177375][ T3731]  __sk_free+0x812/0x8c0
[  179.178032][ T3731]  sk_free+0x97/0x130
[  179.178686][ T3731]  l2cap_sock_release+0x3d5/0x4d0
[  179.179457][ T3731]  sock_close+0x150/0x450
[  179.180117][ T3731]  __fput+0x6bd/0xf00
[  179.180787][ T3731]  ____fput+0x37/0x40
[  179.181481][ T3731]  task_work_run+0x140/0x280
[  179.182219][ T3731]  do_exit+0xe51/0x3e60
[  179.182930][ T3731]  do_group_exit+0x20e/0x450
[  179.183656][ T3731]  get_signal+0x2dfb/0x38f0
[  179.184344][ T3731]  arch_do_signal_or_restart+0xaa/0xe10
[  179.185266][ T3731]  exit_to_user_mode_prepare+0x2d2/0x560
[  179.186136][ T3731]  syscall_exit_to_user_mode+0x35/0x60
[  179.186984][ T3731]  do_syscall_64+0xc5/0x140
[  179.187681][ T3731]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  179.188604][ T3731] =====================================================

In our case, there are two Thread A and B:

Context: Thread A:              Context: Thread B:

l2cap_chan_timeout()            __se_sys_shutdown()
  l2cap_chan_close()              l2cap_sock_shutdown()
    l2cap_chan_del()                l2cap_chan_close()
      l2cap_sock_teardown_cb()        l2cap_sock_teardown_cb()

Once l2cap_sock_teardown_cb() excuted, this sock will be marked as SOCK_ZAPPED,
and can be treated as killable in l2cap_sock_kill() if sock_orphan() has
excuted, at this time we close sock through sock_close() which end to call
l2cap_sock_kill() like Thread C:

Context: Thread C:

sock_close()
  l2cap_sock_release()
    sock_orphan()
    l2cap_sock_kill()  #free sock if refcnt is 1

If C completed, Once A or B reaches l2cap_sock_teardown_cb() again,
use-after-free happened.

We should set chan->data to NULL if sock is destructed, for telling teardown
operation is not allowed in l2cap_sock_teardown_cb(), and also we should
avoid killing an already killed socket in l2cap_sock_close_cb().

Signed-off-by: Wang ShaoBo 
Signed-off-by: Luiz Augusto von Dentz 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Sasha Levin

Bluetooth: sco: Fix lock_sock() blockage by memcpy_from_msg()

2021-11-26T10:58:36+00:00

[ Upstream commit 99c23da0eed4fd20cae8243f2b51e10e66aa0951 ]

The sco_send_frame() also takes lock_sock() during memcpy_from_msg()
call that may be endlessly blocked by a task with userfaultd
technique, and this will result in a hung task watchdog trigger.

Just like the similar fix for hci_sock_sendmsg() in commit
92c685dc5de0 ("Bluetooth: reorganize functions..."), this patch moves
the  memcpy_from_msg() out of lock_sock() for addressing the hang.

This should be the last piece for fixing CVE-2021-3640 after a few
already queued fixes.

Signed-off-by: Takashi Iwai 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Sasha Levin

Bluetooth: skip invalid hci_sync_conn_complete_evt

2021-09-22T09:41:25+00:00

[ Upstream commit 92fe24a7db751b80925214ede43f8d2be792ea7b ]

Syzbot reported a corrupted list in kobject_add_internal [1]. This
happens when multiple HCI_EV_SYNC_CONN_COMPLETE event packets with
status 0 are sent for the same HCI connection. This causes us to
register the device more than once which corrupts the kset list.

As this is forbidden behavior, we add a check for whether we're
trying to process the same HCI_EV_SYNC_CONN_COMPLETE event multiple
times for one connection. If that's the case, the event is invalid, so
we report an error that the device is misbehaving, and ignore the
packet.

Link: https://syzkaller.appspot.com/bug?extid=66264bf2fd0476be7e6c [1]
Reported-by: syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com
Tested-by: syzbot+66264bf2fd0476be7e6c@syzkaller.appspotmail.com
Signed-off-by: Desmond Cheong Zhi Xi 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Sasha Levin

Bluetooth: add timeout sanity check to hci_inquiry

2021-09-22T09:41:21+00:00

[ Upstream commit f41a4b2b5eb7872109723dab8ae1603bdd9d9ec1 ]

Syzbot hit "task hung" bug in hci_req_sync(). The problem was in
unreasonable huge inquiry timeout passed from userspace.
Fix it by adding sanity check for timeout value to hci_inquiry().

Since hci_inquiry() is the only user of hci_req_sync() with user
controlled timeout value, it makes sense to check timeout value in
hci_inquiry() and don't touch hci_req_sync().

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-and-tested-by: syzbot+be2baed593ea56c6a84c@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Sasha Levin

Bluetooth: Move shutdown callback before flushing tx and rx queue

2021-09-22T09:41:21+00:00

[ Upstream commit 0ea53674d07fb6db2dd7a7ec2fdc85a12eb246c2 ]

Commit 0ea9fd001a14 ("Bluetooth: Shutdown controller after workqueues
are flushed or cancelled") introduced a regression that makes mtkbtsdio
driver stops working:
[   36.593956] Bluetooth: hci0: Firmware already downloaded
[   46.814613] Bluetooth: hci0: Execution of wmt command timed out
[   46.814619] Bluetooth: hci0: Failed to send wmt func ctrl (-110)

The shutdown callback depends on the result of hdev->rx_work, so we
should call it before flushing rx_work:
-> btmtksdio_shutdown()
 -> mtk_hci_wmt_sync()
  -> __hci_cmd_send()
   -> wait for BTMTKSDIO_TX_WAIT_VND_EVT gets cleared

-> btmtksdio_recv_event()
 -> hci_recv_frame()
  -> queue_work(hdev->workqueue, &hdev->rx_work)
   -> clears BTMTKSDIO_TX_WAIT_VND_EVT

So move the shutdown callback before flushing TX/RX queue to resolve the
issue.

Reported-and-tested-by: Mattijs Korpershoek 
Tested-by: Hsin-Yi Wang 
Cc: Guenter Roeck 
Fixes: 0ea9fd001a14 ("Bluetooth: Shutdown controller after workqueues are flushed or cancelled")
Signed-off-by: Kai-Heng Feng 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Sasha Levin

Bluetooth: fix repeated calls to sco_sock_kill

2021-09-22T09:41:20+00:00

[ Upstream commit e1dee2c1de2b4dd00eb44004a4bda6326ed07b59 ]

In commit 4e1a720d0312 ("Bluetooth: avoid killing an already killed
socket"), a check was added to sco_sock_kill to skip killing a socket
if the SOCK_DEAD flag was set.

This was done after a trace for a use-after-free bug showed that the
same sock pointer was being killed twice.

Unfortunately, this check prevents sco_sock_kill from running on any
socket. sco_sock_kill kills a socket only if it's zapped and orphaned,
however sock_orphan announces that the socket is dead before detaching
it. i.e., orphaned sockets have the SOCK_DEAD flag set.

To fix this, we remove the check for SOCK_DEAD, and avoid repeated
calls to sco_sock_kill by removing incorrect calls in:

1. sco_sock_timeout. The socket should not be killed on timeout as
further processing is expected to be done. For example,
sco_sock_connect sets the timer then waits for the socket to be
connected or for an error to be returned.

2. sco_conn_del. This function should clean up resources for the
connection, but the socket itself should be cleaned up in
sco_sock_release.

3. sco_sock_close. Calls to sco_sock_close in sco_sock_cleanup_listen
and sco_sock_release are followed by sco_sock_kill. Hence the
duplicated call should be removed.

Fixes: 4e1a720d0312 ("Bluetooth: avoid killing an already killed socket")
Signed-off-by: Desmond Cheong Zhi Xi 
Signed-off-by: Luiz Augusto von Dentz 
Signed-off-by: Sasha Levin

Bluetooth: increase BTNAMSIZ to 21 chars to fix potential buffer overflow

2021-09-22T09:41:20+00:00

[ Upstream commit 713baf3dae8f45dc8ada4ed2f5fdcbf94a5c274d ]

An earlier commit replaced using batostr to using %pMR sprintf for the
construction of session->name. Static analysis detected that this new
method can use a total of 21 characters (including the trailing '\0')
so we need to increase the BTNAMSIZ from 18 to 21 to fix potential
buffer overflows.

Addresses-Coverity: ("Out-of-bounds write")
Fixes: fcb73338ed53 ("Bluetooth: Use %pMR in sprintf/seq_printf instead of batostr")
Signed-off-by: Colin Ian King 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Sasha Levin

Bluetooth: sco: prevent information leak in sco_conn_defer_accept()

2021-09-22T09:41:20+00:00

[ Upstream commit 59da0b38bc2ea570ede23a3332ecb3e7574ce6b2 ]

Smatch complains that some of these struct members are not initialized
leading to a stack information disclosure:

    net/bluetooth/sco.c:778 sco_conn_defer_accept() warn:
    check that 'cp.retrans_effort' doesn't leak information

This seems like a valid warning.  I've added a default case to fix
this issue.

Fixes: 2f69a82acf6f ("Bluetooth: Use voice setting in deferred SCO connection request")
Signed-off-by: Dan Carpenter 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Sasha Levin

Bluetooth: hidp: use correct wait queue when removing ctrl_wait

2021-08-26T12:37:50+00:00

[ Upstream commit cca342d98bef68151a80b024f7bf5f388d1fbdea ]

A different wait queue was used when removing ctrl_wait than when adding
it. This effectively made the remove operation without locking compared
to other operations on the wait queue ctrl_wait was part of. This caused
issues like below where dead000000000100 is LIST_POISON1 and
dead000000000200 is LIST_POISON2.

 list_add corruption. next->prev should be prev (ffffffc1b0a33a08), \
	but was dead000000000200. (next=ffffffc03ac77de0).
 ------------[ cut here ]------------
 CPU: 3 PID: 2138 Comm: bluetoothd Tainted: G           O    4.4.238+ #9
 ...
 ---[ end trace 0adc2158f0646eac ]---
 Call trace:
 [] __list_add+0x38/0xb0
 [] add_wait_queue+0x4c/0x68
 [] __pollwait+0xec/0x100
 [] bt_sock_poll+0x74/0x200
 [] sock_poll+0x110/0x128
 [] do_sys_poll+0x220/0x480
 [] SyS_poll+0x80/0x138
 [] __sys_trace_return+0x0/0x4

 Unable to handle kernel paging request at virtual address dead000000000100
 ...
 CPU: 4 PID: 5387 Comm: kworker/u15:3 Tainted: G        W  O    4.4.238+ #9
 ...
 Call trace:
  [] __wake_up_common+0x7c/0xa8
  [] __wake_up+0x50/0x70
  [] sock_def_wakeup+0x58/0x60
  [] l2cap_sock_teardown_cb+0x200/0x224
  [] l2cap_chan_del+0xa4/0x298
  [] l2cap_conn_del+0x118/0x198
  [] l2cap_disconn_cfm+0x6c/0x78
  [] hci_event_packet+0x564/0x2e30
  [] hci_rx_work+0x10c/0x360
  [] process_one_work+0x268/0x460
  [] worker_thread+0x268/0x480
  [] kthread+0x118/0x128
  [] ret_from_fork+0x10/0x20
  ---[ end trace 0adc2158f0646ead ]---

Signed-off-by: Ole Bjørn Midtbø 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Sasha Levin

Bluetooth: defer cleanup of resources in hci_unregister_dev()

2021-08-15T10:59:55+00:00

[ Upstream commit e04480920d1eec9c061841399aa6f35b6f987d8b ]

syzbot is hitting might_sleep() warning at hci_sock_dev_event() due to
calling lock_sock() with rw spinlock held [1].

It seems that history of this locking problem is a trial and error.

Commit b40df5743ee8 ("[PATCH] bluetooth: fix socket locking in
hci_sock_dev_event()") in 2.6.21-rc4 changed bh_lock_sock() to
lock_sock() as an attempt to fix lockdep warning.

Then, commit 4ce61d1c7a8e ("[BLUETOOTH]: Fix locking in
hci_sock_dev_event().") in 2.6.22-rc2 changed lock_sock() to
local_bh_disable() + bh_lock_sock_nested() as an attempt to fix the
sleep in atomic context warning.

Then, commit 4b5dd696f81b ("Bluetooth: Remove local_bh_disable() from
hci_sock.c") in 3.3-rc1 removed local_bh_disable().

Then, commit e305509e678b ("Bluetooth: use correct lock to prevent UAF
of hdev object") in 5.13-rc5 again changed bh_lock_sock_nested() to
lock_sock() as an attempt to fix CVE-2021-3573.

This difficulty comes from current implementation that
hci_sock_dev_event(HCI_DEV_UNREG) is responsible for dropping all
references from sockets because hci_unregister_dev() immediately
reclaims resources as soon as returning from
hci_sock_dev_event(HCI_DEV_UNREG).

But the history suggests that hci_sock_dev_event(HCI_DEV_UNREG) was not
doing what it should do.

Therefore, instead of trying to detach sockets from device, let's accept
not detaching sockets from device at hci_sock_dev_event(HCI_DEV_UNREG),
by moving actual cleanup of resources from hci_unregister_dev() to
hci_cleanup_dev() which is called by bt_host_release() when all
references to this unregistered device (which is a kobject) are gone.

Since hci_sock_dev_event(HCI_DEV_UNREG) no longer resets
hci_pi(sk)->hdev, we need to check whether this device was unregistered
and return an error based on HCI_UNREGISTER flag.  There might be subtle
behavioral difference in "monitor the hdev" functionality; please report
if you found something went wrong due to this patch.

Link: https://syzkaller.appspot.com/bug?extid=a5df189917e79d5e59c9 [1]
Reported-by: syzbot 
Suggested-by: Linus Torvalds 
Signed-off-by: Tetsuo Handa 
Fixes: e305509e678b ("Bluetooth: use correct lock to prevent UAF of hdev object")
Acked-by: Luiz Augusto von Dentz 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin