commit 7835fcfd132eb88b87e8eb901f88436f63ab60f7 upstream.
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: 31ad169148 ("Bluetooth: Add conn info lifetime parameters to debugfs")
Fixes: 729a1051da ("Bluetooth: Expose default LE advertising interval via debugfs")
Fixes: 71c3b60ec6 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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: 18f81241b7 ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
