Bluetooth: Fix TOCTOU in HCI debugfs implementation

struct hci_dev members conn_info_max_age, conn_info_min_age,
le_conn_max_interval, le_conn_min_interval, le_adv_max_interval,
and le_adv_min_interval can be modified from the HCI core code, as well
through debugfs.

The debugfs implementation, that's only available to privileged users,
will check for boundaries, making sure that the minimum value being set
is strictly above the maximum value that already exists, and vice-versa.

However, as both minimum and maximum values can be changed concurrently
to us modifying them, we need to make sure that the value we check is
the value we end up using.

For example, with ->conn_info_max_age set to 10, conn_info_min_age_set()
gets called from vfs handlers to set conn_info_min_age to 8.

In conn_info_min_age_set(), this goes through:
if (val == 0 || val > hdev->conn_info_max_age)
return -EINVAL;

Concurrently, conn_info_max_age_set() gets called to set to set the
conn_info_max_age to 7:
if (val == 0 || val > hdev->conn_info_max_age)
return -EINVAL;
That check will also pass because we used the old value (10) for
conn_info_max_age.

After those checks that both passed, the struct hci_dev access
is mutex-locked, disabling concurrent access, but that does not matter
because the invalid value checks both passed, and we'll end up with
conn_info_min_age = 8 and conn_info_max_age = 7

To fix this problem, we need to lock the structure access before so the
check and assignment are not interrupted.

This fix was originally devised by the BassCheck[1] team, and
considered the problem to be an atomicity one. This isn't the case as
there aren't any concerns about the variable changing while we check it,
but rather after we check it parallel to another change.

This patch fixes CVE-2024-24858 and CVE-2024-24857.

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

Co-developed-by: Gui-Dong Han <2045gemini@gmail.com>
Signed-off-by: Gui-Dong Han <2045gemini@gmail.com>
Link: https://lore.kernel.org/linux-bluetooth/20231222161317.6255-1-2045gemini@gmail.com/
Link: https://nvd.nist.gov/vuln/detail/CVE-2024-24858
Link: https://lore.kernel.org/linux-bluetooth/20231222162931.6553-1-2045gemini@gmail.com/
Link: https://lore.kernel.org/linux-bluetooth/20231222162310.6461-1-2045gemini@gmail.com/
Link: https://nvd.nist.gov/vuln/detail/CVE-2024-24857
Fixes: 31ad169148df ("Bluetooth: Add conn info lifetime parameters to debugfs")
Fixes: 729a1051da6f ("Bluetooth: Expose default LE advertising interval via debugfs")
Fixes: 71c3b60ec6d2 ("Bluetooth: Move BR/EDR debugfs file creation into hci_debugfs.c")
Signed-off-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

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

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 <luiz.von.dentz@intel.com>

Bluetooth: hci_debugfs: Use kstrtobool() instead of strtobool()

strtobool() is the same as kstrtobool().
However, the latter is more used within the kernel.

In order to remove strtobool() and slightly simplify kstrtox.h, switch to
the other function name.

While at it, include the corresponding header file (<linux/kstrtox.h>)

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Bluetooth: fix inconsistent indenting

Fixed a wrong indentation before "return".This line uses a 7 space
indent instead of a tab.

Signed-off-by: Lanzhe Li <u202212060@hust.edu.cn>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Bluetooth: hci_sync: Fix not able to set force_static_address

force_static_address shall be writable while hdev is initing but is not
considered powered yet since the static address is written only when
powered.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Tested-by: Brian Gix <brian.gix@intel.com>

Bluetooth: hci_debugfs: Fix not checking conn->debugfs

hci_debugfs_create_conn shall check if conn->debugfs has already been
created and don't attempt to overwrite it.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Bluetooth: hci_core: Move all debugfs handling to hci_debugfs.c

This moves hci_debugfs_create_basic to hci_debugfs.c which is where all
the others debugfs entries are handled.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Bluetooth: use inclusive language when filtering devices

This patch replaces some non-inclusive terms based on the appropriate
language mapping table compiled by the Bluetooth SIG:
https://specificationrefs.bluetooth.com/language-mapping/Appropriate_Language_Mapping_Table.pdf

Specifically, these terms are replaced:
blacklist -> reject list
whitelist -> accept list

Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Reviewed-by: Miao-chen Chou <mcchou@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Bluetooth: Coding style fix

1. Add space when needed;
2. Block comments style fix;
3. Move open brace '{' following function definitions to the next line;
4. Remove unnecessary braces '{}' for single statement blocks.

Signed-off-by: Meng Yu <yumeng18@huawei.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Bluetooth: fix coccicheck warnings debugfs

Use DEFINE_DEBUGFS_ATTRIBUTE rather than DEFINE_SIMPLE_ATTRIBUTE
for debugfs files.

Reported-by: Abaci Robot<abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Zhong <abaci-bugfix@linux.alibaba.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Bluetooth: Move force_bredr_smp debugfs into hci_debugfs_create_bredr

Avoid multiple attempts to create the debugfs entry, force_bredr_smp,
by moving it from the SMP registration to the BR/EDR controller init
section. hci_debugfs_create_bredr is only called when HCI_SETUP and
HCI_CONFIG is not set.

Signed-off-by: Claire Chang <tientzu@chromium.org>
Reviewed-by: Alain Michaud <alainm@chromium.org>
Reviewed-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Bluetooth: debugfs option to unset MITM flag

The BT qualification test SM/MAS/PKE/BV-01-C needs us to turn off
the MITM flag when pairing, and at the same time also set the io
capability to something other than no input no output.

Currently the MITM flag is only unset when the io capability is set
to no input no output, therefore the test cannot be executed.

This patch introduces a debugfs option to force MITM flag to be
turned off.

Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Bluetooth: Move {min,max}_key_size debugfs into hci_debugfs_create_le

The debugfs entries for {min,max}_key_size are created during SMP
registration and thus it might lead to multiple attempts to create the
same entries. Avoid this by moving them to the LE controller init
section.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Implementation of MGMT_OP_SET_BLOCKED_KEYS.

MGMT command is added to receive the list of blocked keys from
user-space.

The list is used to:
1) Block keys from being distributed by the device during
the ke distribution phase of SMP.
2) Filter out any keys that were previously saved so
they are no longer used.

Signed-off-by: Alain Michaud <alainm@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Bluetooth: Add debug setting for changing minimum encryption key size

For testing and qualification purposes it is useful to allow changing
the minimum encryption key size value that the host stack is going to
enforce. This adds a new debugfs setting min_encrypt_key_size to achieve
this functionality.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Add support for LE ping feature

Changes made to add HCI Write Authenticated Payload timeout
command for LE Ping feature.

As per the Core Specification 5.0 Volume 2 Part E Section 7.3.94,
the following code changes implements
HCI Write Authenticated Payload timeout command for LE Ping feature.

Signed-off-by: Spoorthi Ravishankar Koppad <spoorthix.k@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Bluetooth: Store Resolv list size

When the controller supports the Read LE Resolv List size feature, the
maximum list size are read and now stored.

Before patch:
< HCI Command: LE Read White List... (0x08|0x000f) plen 0 #55 [hci0] 17.979791
> HCI Event: Command Complete (0x0e) plen 5 #56 [hci0] 17.980629
LE Read White List Size (0x08|0x000f) ncmd 1
Status: Success (0x00)
Size: 25
< HCI Command: LE Clear White List (0x08|0x0010) plen 0 #57 [hci0] 17.980786
> HCI Event: Command Complete (0x0e) plen 4 #58 [hci0] 17.981627
LE Clear White List (0x08|0x0010) ncmd 1
Status: Success (0x00)
< HCI Command: LE Read Maximum Dat.. (0x08|0x002f) plen 0 #59 [hci0] 17.981786
> HCI Event: Command Complete (0x0e) plen 12 #60 [hci0] 17.982636
LE Read Maximum Data Length (0x08|0x002f) ncmd 1
Status: Success (0x00)
Max TX octets: 251
Max TX time: 17040
Max RX octets: 251
Max RX time: 17040

After patch:
< HCI Command: LE Read White List... (0x08|0x000f) plen 0 #55 [hci0] 13.338168
> HCI Event: Command Complete (0x0e) plen 5 #56 [hci0] 13.338842
LE Read White List Size (0x08|0x000f) ncmd 1
Status: Success (0x00)
Size: 25
< HCI Command: LE Clear White List (0x08|0x0010) plen 0 #57 [hci0] 13.339029
> HCI Event: Command Complete (0x0e) plen 4 #58 [hci0] 13.339939
LE Clear White List (0x08|0x0010) ncmd 1
Status: Success (0x00)
< HCI Command: LE Read Resolving L.. (0x08|0x002a) plen 0 #59 [hci0] 13.340152
> HCI Event: Command Complete (0x0e) plen 5 #60 [hci0] 13.340952
LE Read Resolving List Size (0x08|0x002a) ncmd 1
Status: Success (0x00)
Size: 25
< HCI Command: LE Read Maximum Dat.. (0x08|0x002f) plen 0 #61 [hci0] 13.341180
> HCI Event: Command Complete (0x0e) plen 12 #62 [hci0] 13.341898
LE Read Maximum Data Length (0x08|0x002f) ncmd 1
Status: Success (0x00)
Max TX octets: 251
Max TX time: 17040
Max RX octets: 251
Max RX time: 17040

Signed-off-by: Ankit Navik <ankit.p.navik@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Bluetooth: Re-use kstrtobool_from_user()

Re-use kstrtobool_from_user() instead of open coded variant.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

seq_file: Introduce DEFINE_SHOW_ATTRIBUTE() helper macro

The DEFINE_SHOW_ATTRIBUTE() helper macro would be useful for current
users, which are many of them, and for new comers to decrease code
duplication.

Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Darren Hart (VMware) <dvhart@infradead.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Bluetooth: introduce DEFINE_SHOW_ATTRIBUTE() macro

This macro deduplicates a lot of similar code across the hci_debugfs.c
module. Targeting to be moved to seq_file.h eventually.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Bluetooth: Utilize %*ph specifier

Instead of open coding byte-by-byte printing, re-use %*ph specifier.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Bluetooth: Add debugfs fields for hardware and firmware info

Some Bluetooth controllers allow for reading hardware and firmware
related vendor specific infos. If they are available, then they can be
exposed via debugfs now.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Expose current Device ID information via debugfs

For debugging purposes it is good to be able to read the current
configured Device ID details.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Expose quirks through debugfs

This patch expose controller quirks through debugfs. It would be
useful for BlueZ tests using vhci. Currently there is no way to
test quirk dependent behaviour. It might be also useful for manual
testing.

Signed-off-by: Jakub Pawlowski <jpawlowski@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

Bluetooth: The P-256 randomizer is 16 octets long and not 19 octets

This seems to be a simple typo in the debugfs entry for the remote
out-of-band data entries.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Merge hdev->dbg_flags fields into hdev->dev_flags

With the extension of hdev->dev_flags utilizing a bitmap now, the space
is no longer restricted. Merge the hdev->dbg_flags into hdev->dev_flags
to save space on 64-bit architectures. On 32-bit architectures no size
reduction happens.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Introduce hci_dev_test_flag helper macro

Instead of manually coding test_bit on hdev->dev_flags all the time,
use hci_dev_test_flag helper macro.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Expose remote OOB information as debugfs entry

For debugging purposes it is good to know which OOB data is actually
currently loaded for each controller. So expose that list via debugfs.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Expose hardware error code as debugfs entry

When the Hardware Error event is send by the controller, the Bluetooth
core stores the error code. Expose it via debugfs so it can be retrieved
later on.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Expose debug keys usage setting via debugfs

To allow easier debugging when debug keys are generated, provide debugfs
entry for checking the setting of debug keys usage.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Expose Secure Simple Pairing debug mode setting in debugfs

The value of the ssp_debug_mode should be accessible via debugfs to be
able to determine if a BR/EDR controller generates debugs keys or not.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Fix scope of sc_only_mode debugfs entry

The sc_only_mode debugfs entry is used to read the current state of the
Secure Connections Only mode. Before Bluetooth 4.2 this mode was only
for BR/EDR controllers and with that tight to the support Secure Simple
Pairing. Since Secure Connections is now available for BR/EDR and LE
this debugfs entry is no longer correctly place.

Move it to the common section and enable it when either BR/EDR Secure
Connections feature is supported or when the controller has LE support.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Remove no longer needed force_sc_support debugfs option

The force_sc_support debugfs option was introduced to easily work with
pre-production Bluetooth 4.1 silicon. This option is no longer needed
since controllers supporting BR/EDR Secure Connections feature are now
available.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Remove broken force_lesc_support debugfs option

The force_lesc_support debugfs option never really worked. It has a race
condition between creating the debugfs entry and registering the L2CAP
fixed channel for BR/EDR SMP support.

Also this has been replaced with a working force_bredr_smp debugfs
switch that developers can use now.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Create debugfs directory for each connection handle

For every internal representation of a Bluetooth connection which is
identified by hci_conn, create a debugfs directory with the handle
number as directory name.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Move LE debugfs file creation into hci_debugfs.c

This patch moves the creation of the debugs files for LE controllers
into hci_debugfs.c file.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Move BR/EDR debugfs file creation into hci_debugfs.c

This patch moves the creation of the debugs files for BR/EDR controllers
into hci_debugfs.c file.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Move common debugfs file creation into hci_debugfs.c

This patch moves the creation of the debugs files common for all
controllers into hci_debugfs.c file.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

Bluetooth: Add skeleton functions for debugfs creation

The debugfs file creation has been part of the core initialization
handling of controllers. With the introduction of Bluetooth 4.2 core
specification, the number of debugfs files is increasing even further.

To avoid cluttering the core controller handling, create a separate
file hci_debugfs.c to centralize all debugfs file creation. For now
leave the current files in the core, but in the future all debugfs
file creation will be moved.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>