linux-stable.git/net/bluetooth, branch v6.1.76

Bluetooth: Fix atomicity violation in {min,max}_key_size_set

2024-01-25T23:27:43+00:00

commit da9065caa594d19b26e1a030fd0cc27bd365d685 upstream.

In min_key_size_set():
    if (val > hdev->le_max_key_size || val < SMP_MIN_ENC_KEY_SIZE)
        return -EINVAL;
    hci_dev_lock(hdev);
    hdev->le_min_key_size = val;
    hci_dev_unlock(hdev);

In max_key_size_set():
    if (val > SMP_MAX_ENC_KEY_SIZE || val < hdev->le_min_key_size)
        return -EINVAL;
    hci_dev_lock(hdev);
    hdev->le_max_key_size = val;
    hci_dev_unlock(hdev);

The atomicity violation occurs due to concurrent execution of set_min and
set_max funcs.Consider a scenario where setmin writes a new, valid 'min'
value, and concurrently, setmax writes a value that is greater than the
old 'min' but smaller than the new 'min'. In this case, setmax might check
against the old 'min' value (before acquiring the lock) but write its
value after the 'min' has been updated by setmin. This leads to a
situation where the 'max' value ends up being smaller than the 'min'
value, which is an inconsistency.

This possible bug is found by an experimental static analysis tool
developed by our team, BassCheck[1]. This tool analyzes the locking APIs
to extract function pairs that can be concurrently executed, and then
analyzes the instructions in the paired functions to identify possible
concurrency bugs including data races and atomicity violations. The above
possible bug is reported when our tool analyzes the source code of
Linux 5.17.

To resolve this issue, it is suggested to encompass the validity checks
within the locked sections in both set_min and set_max funcs. The
modification ensures that the validation of 'val' against the
current min/max values is atomic, thus maintaining the integrity of the
settings. With this patch applied, our tool no longer reports the bug,
with the kernel configuration allyesconfig for x86_64. Due to the lack of
associated hardware, we cannot test the patch in runtime testing, and just
verify it according to the code logic.

[1] https://sites.google.com/view/basscheck/

Fixes: 18f81241b74f ("Bluetooth: Move {min,max}_key_size debugfs ...")
Cc: stable@vger.kernel.org
Signed-off-by: Gui-Dong Han <2045gemini@gmail.com>
Signed-off-by: Luiz Augusto von Dentz 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: Fix bogus check for re-auth no supported with non-ssp

2024-01-25T23:27:30+00:00

[ Upstream commit d03376c185926098cb4d668d6458801eb785c0a5 ]

This reverts 19f8def031bfa50c579149b200bfeeb919727b27
"Bluetooth: Fix auth_complete_evt for legacy units" which seems to be
working around a bug on a broken controller rather then any limitation
imposed by the Bluetooth spec, in fact if there ws not possible to
re-auth the command shall fail not succeed.

Fixes: 19f8def031bf ("Bluetooth: Fix auth_complete_evt for legacy units")
Signed-off-by: Luiz Augusto von Dentz 
Signed-off-by: Sasha Levin

Bluetooth: Add more enc key size check

2024-01-01T12:39:03+00:00

commit 04a342cc49a8522e99c9b3346371c329d841dcd2 upstream.

When we are slave role and receives l2cap conn req when encryption has
started, we should check the enc key size to avoid KNOB attack or BLUFFS
attack.
From SIG recommendation, implementations are advised to reject
service-level connections on an encrypted baseband link with key
strengths below 7 octets.
A simple and clear way to achieve this is to place the enc key size
check in hci_cc_read_enc_key_size()

The btmon log below shows the case that lacks enc key size check.

> HCI Event: Connect Request (0x04) plen 10
        Address: BB:22:33:44:55:99 (OUI BB-22-33)
        Class: 0x480104
          Major class: Computer (desktop, notebook, PDA, organizers)
          Minor class: Desktop workstation
          Capturing (Scanner, Microphone)
          Telephony (Cordless telephony, Modem, Headset)
        Link type: ACL (0x01)
< HCI Command: Accept Connection Request (0x01|0x0009) plen 7
        Address: BB:22:33:44:55:99 (OUI BB-22-33)
        Role: Peripheral (0x01)
> HCI Event: Command Status (0x0f) plen 4
      Accept Connection Request (0x01|0x0009) ncmd 2
        Status: Success (0x00)
> HCI Event: Connect Complete (0x03) plen 11
        Status: Success (0x00)
        Handle: 1
        Address: BB:22:33:44:55:99 (OUI BB-22-33)
        Link type: ACL (0x01)
        Encryption: Disabled (0x00)
...

> HCI Event: Encryption Change (0x08) plen 4
        Status: Success (0x00)
        Handle: 1 Address: BB:22:33:44:55:99 (OUI BB-22-33)
        Encryption: Enabled with E0 (0x01)
< HCI Command: Read Encryption Key Size (0x05|0x0008) plen 2
        Handle: 1 Address: BB:22:33:44:55:99 (OUI BB-22-33)
> HCI Event: Command Complete (0x0e) plen 7
      Read Encryption Key Size (0x05|0x0008) ncmd 2
        Status: Success (0x00)
        Handle: 1 Address: BB:22:33:44:55:99 (OUI BB-22-33)
        Key size: 6
// We should check the enc key size
...

> ACL Data RX: Handle 1 flags 0x02 dlen 12
      L2CAP: Connection Request (0x02) ident 3 len 4
        PSM: 25 (0x0019)
        Source CID: 64
< ACL Data TX: Handle 1 flags 0x00 dlen 16
      L2CAP: Connection Response (0x03) ident 3 len 8
        Destination CID: 64
        Source CID: 64
        Result: Connection pending (0x0001)
        Status: Authorization pending (0x0002)
> HCI Event: Number of Completed Packets (0x13) plen 5
        Num handles: 1
        Handle: 1 Address: BB:22:33:44:55:99 (OUI BB-22-33)
        Count: 1
        #35: len 16 (25 Kb/s)
        Latency: 5 msec (2-7 msec ~4 msec)
< ACL Data TX: Handle 1 flags 0x00 dlen 16
      L2CAP: Connection Response (0x03) ident 3 len 8
        Destination CID: 64
        Source CID: 64
        Result: Connection successful (0x0000)
        Status: No further information available (0x0000)

Cc: stable@vger.kernel.org
Signed-off-by: Alex Lu 
Signed-off-by: Max Chou 
Signed-off-by: Luiz Augusto von Dentz 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: MGMT/SMP: Fix address type when using SMP over BREDR/LE

2024-01-01T12:39:03+00:00

commit 59b047bc98084f8af2c41483e4d68a5adf2fa7f7 upstream.

If two Bluetooth devices both support BR/EDR and BLE, and also
support Secure Connections, then they only need to pair once.
The LTK generated during the LE pairing process may be converted
into a BR/EDR link key for BR/EDR transport, and conversely, a
link key generated during the BR/EDR SSP pairing process can be
converted into an LTK for LE transport. Hence, the link type of
the link key and LTK is not fixed, they can be either an LE LINK
or an ACL LINK.

Currently, in the mgmt_new_irk/ltk/crsk/link_key functions, the
link type is fixed, which could lead to incorrect address types
being reported to the application layer. Therefore, it is necessary
to add link_type/addr_type to the smp_irk/ltk/crsk and link_key,
to ensure the generation of the correct address type.

SMP over BREDR:
Before Fix:
> ACL Data RX: Handle 11 flags 0x02 dlen 12
        BR/EDR SMP: Identity Address Information (0x09) len 7
        Address: F8:7D:76:F2:12:F3 (OUI F8-7D-76)
@ MGMT Event: New Identity Resolving Key (0x0018) plen 30
        Random address: 00:00:00:00:00:00 (Non-Resolvable)
        LE Address: F8:7D:76:F2:12:F3 (OUI F8-7D-76)
@ MGMT Event: New Long Term Key (0x000a) plen 37
        LE Address: F8:7D:76:F2:12:F3 (OUI F8-7D-76)
        Key type: Authenticated key from P-256 (0x03)

After Fix:
> ACL Data RX: Handle 11 flags 0x02 dlen 12
      BR/EDR SMP: Identity Address Information (0x09) len 7
        Address: F8:7D:76:F2:12:F3 (OUI F8-7D-76)
@ MGMT Event: New Identity Resolving Key (0x0018) plen 30
        Random address: 00:00:00:00:00:00 (Non-Resolvable)
        BR/EDR Address: F8:7D:76:F2:12:F3 (OUI F8-7D-76)
@ MGMT Event: New Long Term Key (0x000a) plen 37
        BR/EDR Address: F8:7D:76:F2:12:F3 (OUI F8-7D-76)
        Key type: Authenticated key from P-256 (0x03)

SMP over LE:
Before Fix:
@ MGMT Event: New Identity Resolving Key (0x0018) plen 30
        Random address: 5F:5C:07:37:47:D5 (Resolvable)
        LE Address: F8:7D:76:F2:12:F3 (OUI F8-7D-76)
@ MGMT Event: New Long Term Key (0x000a) plen 37
        LE Address: F8:7D:76:F2:12:F3 (OUI F8-7D-76)
        Key type: Authenticated key from P-256 (0x03)
@ MGMT Event: New Link Key (0x0009) plen 26
        BR/EDR Address: F8:7D:76:F2:12:F3 (OUI F8-7D-76)
        Key type: Authenticated Combination key from P-256 (0x08)

After Fix:
@ MGMT Event: New Identity Resolving Key (0x0018) plen 30
        Random address: 5E:03:1C:00:38:21 (Resolvable)
        LE Address: F8:7D:76:F2:12:F3 (OUI F8-7D-76)
@ MGMT Event: New Long Term Key (0x000a) plen 37
        LE Address: F8:7D:76:F2:12:F3 (OUI F8-7D-76)
        Key type: Authenticated key from P-256 (0x03)
@ MGMT Event: New Link Key (0x0009) plen 26
        Store hint: Yes (0x01)
        LE Address: F8:7D:76:F2:12:F3 (OUI F8-7D-76)
        Key type: Authenticated Combination key from P-256 (0x08)

Cc: stable@vger.kernel.org
Signed-off-by: Xiao Yao 
Signed-off-by: Luiz Augusto von Dentz 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: L2CAP: Send reject on command corrupted request

2024-01-01T12:39:03+00:00

commit 78b99eb1faa7371bf9c534690f26a71b6996622d upstream.

L2CAP/COS/CED/BI-02-C PTS test send a malformed L2CAP signaling packet
with 2 commands in it (a connection request and an unknown command) and
expect to get a connection response packet and a command reject packet.
The second is currently not sent.

Cc: stable@vger.kernel.org
Signed-off-by: Frédéric Danis 
Signed-off-by: Luiz Augusto von Dentz 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: af_bluetooth: Fix Use-After-Free in bt_sock_recvmsg

2024-01-01T12:39:03+00:00

commit 2e07e8348ea454615e268222ae3fc240421be768 upstream.

This can cause a race with bt_sock_ioctl() because
bt_sock_recvmsg() gets the skb from sk->sk_receive_queue
and then frees it without holding lock_sock.
A use-after-free for a skb occurs with the following flow.
```
bt_sock_recvmsg() -> skb_recv_datagram() -> skb_free_datagram()
bt_sock_ioctl() -> skb_peek()
```
Add lock_sock to bt_sock_recvmsg() to fix this issue.

Cc: stable@vger.kernel.org
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Hyunwoo Kim 
Signed-off-by: Luiz Augusto von Dentz 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: hci_event: Fix not checking if HCI_OP_INQUIRY has been sent

2024-01-01T12:39:03+00:00

commit 99e67d46e5ff3c7c901af6009edec72d3d363be8 upstream.

Before setting HCI_INQUIRY bit check if HCI_OP_INQUIRY was really sent
otherwise the controller maybe be generating invalid events or, more
likely, it is a result of fuzzing tools attempting to test the right
behavior of the stack when unexpected events are generated.

Cc: stable@vger.kernel.org
Link: https://bugzilla.kernel.org/show_bug.cgi?id=218151
Signed-off-by: Luiz Augusto von Dentz 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: hci_event: shut up a false-positive warning

2024-01-01T12:38:57+00:00

[ Upstream commit a5812c68d849505ea657f653446512b85887f813 ]

Turning on -Wstringop-overflow globally exposed a misleading compiler
warning in bluetooth:

net/bluetooth/hci_event.c: In function 'hci_cc_read_class_of_dev':
net/bluetooth/hci_event.c:524:9: error: 'memcpy' writing 3 bytes into a
region of size 0 overflows the destination [-Werror=stringop-overflow=]
  524 |         memcpy(hdev->dev_class, rp->dev_class, 3);
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The problem here is the check for hdev being NULL in bt_dev_dbg() that
leads the compiler to conclude that hdev->dev_class might be an invalid
pointer access.

Add another explicit check for the same condition to make sure gcc sees
this cannot happen.

Fixes: a9de9248064b ("[Bluetooth] Switch from OGF+OCF to using only opcodes")
Fixes: 1b56c90018f0 ("Makefile: Enable -Wstringop-overflow globally")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Luiz Augusto von Dentz 
Signed-off-by: Sasha Levin

Bluetooth: Fix double free in hci_conn_cleanup

2023-11-28T17:06:56+00:00

[ Upstream commit a85fb91e3d728bdfc80833167e8162cce8bc7004 ]

syzbot reports a slab use-after-free in hci_conn_hash_flush [1].
After releasing an object using hci_conn_del_sysfs in the
hci_conn_cleanup function, releasing the same object again
using the hci_dev_put and hci_conn_put functions causes a double free.
Here's a simplified flow:

hci_conn_del_sysfs:
  hci_dev_put
    put_device
      kobject_put
        kref_put
          kobject_release
            kobject_cleanup
              kfree_const
                kfree(name)

hci_dev_put:
  ...
    kfree(name)

hci_conn_put:
  put_device
    ...
      kfree(name)

This patch drop the hci_dev_put and hci_conn_put function
call in hci_conn_cleanup function, because the object is
freed in hci_conn_del_sysfs function.

This patch also fixes the refcounting in hci_conn_add_sysfs() and
hci_conn_del_sysfs() to take into account device_add() failures.

This fixes CVE-2023-28464.

Link: https://syzkaller.appspot.com/bug?id=1bb51491ca5df96a5f724899d1dbb87afda61419 [1]

Signed-off-by: ZhengHan Wang 
Co-developed-by: Luiz Augusto von Dentz 
Signed-off-by: Luiz Augusto von Dentz 
Signed-off-by: Sasha Levin

Bluetooth: hci_sync: Fix Opcode prints in bt_dev_dbg/err

2023-11-20T10:51:55+00:00

[ Upstream commit 530886897c789cf77c9a0d4a7cc5549f0768b5f8 ]

Printed Opcodes may be missing leading zeros:

	Bluetooth: hci0: Opcode 0x c03 failed: -110

Fix this by always printing leading zeros:

	Bluetooth: hci0: Opcode 0x0c03 failed: -110

Fixes: d0b137062b2d ("Bluetooth: hci_sync: Rework init stages")
Fixes: 6a98e3836fa2 ("Bluetooth: Add helper for serialized HCI command execution")
Signed-off-by: Marcel Ziswiler 
Signed-off-by: Luiz Augusto von Dentz 
Signed-off-by: Sasha Levin