NULL checks at line 457: if (!link0 || !link1) {, implies that both
pointers link0 and link1 might be NULL.
Function nfcsim_link_free() dereference pointers link0 and link1.
Add NULL checks before calling nfcsim_link_free() to avoid a
potential NULL pointer dereference.

Addresses-Coverity-ID: 1364857
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Remove unnecessary NULL check for pointer conn_info.
conn_info is set in list_for_each_entry() using container_of(),
which is never NULL.

Addresses-Coverity-ID: 1362349
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Check that the NFC_ATTR_TARGET_INDEX and NFC_ATTR_PROTOCOLS attributes (in
addition to NFC_ATTR_DEVICE_INDEX) are provided by the netlink client
prior to accessing them. This prevents potential unhandled NULL pointer
dereference exceptions which can be triggered by malicious user-mode
programs, if they omit one or both of these attributes.
Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Fix the sockaddr length verification in the connect() handler of NFC/LLCP
sockets, to compare against the size of the actual structure expected on
input (sockaddr_nfc_llcp) instead of its shorter version (sockaddr_nfc).

Both structures are defined in include/uapi/linux/nfc.h. The fields
specific to the _llcp extended struct are as follows:

   276		__u8 dsap; /* Destination SAP, if known */
   277		__u8 ssap; /* Source SAP to be bound to */
   278		char service_name[NFC_LLCP_MAX_SERVICE_NAME]; /* Service name URI */;
   279		size_t service_name_len;

If the caller doesn't provide a sufficiently long sockaddr buffer, these
fields remain uninitialized (and they currently originate from the stack
frame of the top-level sys_connect handler). They are then copied by
llcp_sock_connect() into internal storage (nfc_llcp_sock structure), and
could be subsequently read back through the user-mode getsockname()
function (handled by llcp_sock_getname()). This would result in the
disclosure of up to ~70 uninitialized bytes from the kernel stack to
user-mode clients capable of creating AFC_NFC sockets.
Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

This reverts commit ab714817.

The original commit was designed to handle a bug in the trf7970a NFC
controller where an extra byte was returned in Read Multiple Blocks (RMB)
command responses.  However, it has become less clear whether it is a bug
in the trf7970a or in the tag.  In addition, it was assumed that the extra
byte was always returned but it turns out that is not always the case. The
result is that a byte of good data is trimmed off when the extra byte is
not present ultimately causing the neard deamon to fail the read.

Since the trf7970a driver does not have the context to know when to trim
the byte or not, remove the code from the trf7970a driver all together
(and move it up to the neard daemon).  This has the added benefit of
simplifying the kernel driver and putting the extra complexity into
userspace.

CC: Rob Herring <robh@kernel.org>
CC: devicetree@vger.kernel.org
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Version 1.1 of the NFC Forum's NFC Digital Protocol Technical
Specification dated 2014-07-14 specifies that the NFC-DEP Protocol's
Target WT(nfcdep,max) value is 14.  In version 1.0 it was 8 so change
the value in the Linux NFC-DEP Protocol code accordingly.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Section 4.8.2 (SEL_RES Response) of NFC Forum's NFC Digital Protocol
Technical Specification dated 2010-11-17 clearly states that the size
of a SEL_RES Response is one byte.  Enforce this restriction in the
code.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Omit an extra message for a memory allocation failure in this function.

This issue was detected by using the Coccinelle software.

Link: http://events.linuxfoundation.org/sites/events/files/slides/LCJ16-Refactor_Strings-WSang_0.pdfSigned-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Replace the specification of four data structures by pointer dereferences
as the parameter for the operator "sizeof" to make the corresponding size
determination a bit safer according to the Linux coding style convention.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

The "or" condition (clk_freq != TRF7970A_27MHZ_CLOCK_FREQUENCY) ||
(clk_freq != TRF7970A_13MHZ_CLOCK_FREQUE) will always be true because
clk_freq cannot be equal to two different values at the same time. Use
the  && operator instead of || to fix this.

Detected by CoverityScan, CID#1430468 ("Constant expression result")

Fixes: 837eb4d2 ("NFC: trf7970a: add device tree option for 27MHz clock")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Geoff Lansberry <geoff@kuvee.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

There are no longer platform data files for NFC drivers.
Remove it from MAINTAINERS data base.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Since OF and ACPI case almost the same get rid of code duplication
by moving gpiod_get() calls directly to ->probe().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

In order to make GPIO ACPI library stricter prepare users of
gpiod_get_index() to correctly behave when there no mapping is
provided by firmware.

Here we add explicit mapping between _CRS GpioIo() resources and
their names used in the driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Use unified device properties API in meaningful way.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Since we got rid of platform data, the driver may use GPIO descriptor
directly.

Looking deeply to the use of the GPIO pin it looks like it should be
a GPIO based reset control rather than custom GPIO handling. But this
is out of scope of the change.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

I2C and SPI frameworks followed by IRQ framework do set
interrupt polarity correctly if it's properly specified in firmware
(ACPI or DT).

Get rid of the redundant trick when requesting interrupt.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Legacy platform data must go away. We are on the safe side here since
there are no users of it in the kernel.

If anyone by any odd reason needs it the GPIO lookup tables and
built-in device properties at your service.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

In order to make GPIO ACPI library stricter prepare users of
gpiod_get_index() to correctly behave when there no mapping is
provided by firmware.

Here we add explicit mapping between _CRS GpioIo() resources and
their names used in the driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

It looks like there are two leftovers, at least one of which can leak
the resource (IRQ).

Convert both places to use managed variants of the functions.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

There is no platform code that uses i2c module table.
Remove it altogether and adjust ->probe() to be ->probe_new().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Since OF and ACPI case almost the same get rid of code duplication
by moving gpiod_get() calls directly to ->probe().
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

In order to make GPIO ACPI library stricter prepare users of
gpiod_get_index() to correctly behave when there no mapping is
provided by firmware.

Here we add explicit mapping between _CRS GpioIo() resources and
their names used in the driver.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Switch to use managed variant of acpi_dev_add_driver_gpios() to simplify
error path and fix potentially wrong assignment if ->probe() fails.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Allow gpio 0 to be used for reset signalling, and instead use negative
errnos to disable the reset functionality.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Use the USB-interface rather than parent USB-device device, which is
what this driver binds to, when registering the nci device.

Note that using the right device is important when dealing with device-
managed resources as the interface can be unbound independently of the
parent device.

Also note that private device pointer had already been set by
nfcmrvl_nci_register_dev() so the redundant assignment can therefore be
removed.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Make sure to release the device-node reference when done parsing the
node.

Fixes: e097dc62 ("NFC: nfcmrvl: add UART driver")
Cc: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

The nci-device was never deregistered in the event that
fw-initialisation failed.

Fix this by moving the firmware initialisation before device
registration since the firmware work queue should be available before
registering.

Note that this depends on a recent fix that moved device-name
initialisation back to to nci_allocate_device() as the
firmware-workqueue name is now derived from the nfc-device name.

Fixes: 3194c687 ("NFC: nfcmrvl: add firmware download support")
Cc: stable <stable@vger.kernel.org>     # 4.4
Cc: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Use the nfc- rather than phy-device in firmware-management code that
needs a valid struct device.

This specifically fixes a NULL-pointer dereference in
nfcmrvl_fw_dnld_init() during registration when the underlying tty is
one end of a Unix98 pty.

Note that the driver still uses the phy device for any debugging, which
is fine for now.

Fixes: 3194c687 ("NFC: nfcmrvl: add firmware download support")
Cc: stable <stable@vger.kernel.org>     # 4.4
Cc: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

This specifically fixes resource leaks in the registration error paths.

Device-managed resources is a bad fit for this driver as devices can be
registered from the n_nci line discipline. Firstly, a tty may not even
have a corresponding device (should it be part of a Unix98 pty)
something which would lead to a NULL-pointer dereference when
registering resources.

Secondly, if the tty has a class device, its lifetime exceeds that of
the line discipline, which means that resources would leak every time
the line discipline is closed (or if registration fails).

Currently, the devres interface was only being used to request a reset
gpio despite the fact that it was already explicitly freed in
nfcmrvl_nci_unregister_dev() (along with the private data), something
which also prevented the resource leak at close.

Note that the driver treats gpio number 0 as invalid despite it being
perfectly valid. This will be addressed in a follow-up patch.

Fixes: b2fe288e ("NFC: nfcmrvl: free reset gpio")
Fixes: 4a2b947f ("NFC: nfcmrvl: add chip reset management")
Cc: stable <stable@vger.kernel.org>     # 4.2: b2fe288e
Cc: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Make sure to check the tty-device pointer before trying to access the
parent device to avoid dereferencing a NULL-pointer when the tty is one
end of a Unix98 pty.

Fixes: e097dc62 ("NFC: nfcmrvl: add UART driver")
Cc: stable <stable@vger.kernel.org>     # 4.2
Cc: Vincent Cuissard <cuissard@marvell.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Commit 7eda8b8e ("NFC: Use IDR library to assing NFC devices IDs")
moved device-id allocation and struct-device initialisation from
nfc_allocate_device() to nfc_register_device().

This broke just about every nfc-device-registration error path, which
continue to call nfc_free_device() that tries to put the device
reference of the now uninitialised (but zeroed) struct device:

kobject: '(null)' (ce316420): is not initialized, yet kobject_put() is being called.

The late struct-device initialisation also meant that various work
queues whose names are derived from the nfc device name were also
misnamed:

  421 root         0 SW<  [(null)_nci_cmd_]
  422 root         0 SW<  [(null)_nci_rx_w]
  423 root         0 SW<  [(null)_nci_tx_w]

Move the id-allocation and struct-device initialisation back to
nfc_allocate_device() and fix up the single call site which did not use
nfc_free_device() in its error path.

Fixes: 7eda8b8e ("NFC: Use IDR library to assing NFC devices IDs")
Cc: stable <stable@vger.kernel.org>     # 3.8
Cc: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Clean up coding style issues according to scripts/Lindent.
Some scripts/Lindent changes were reverted when it appeared
to make the code less readable or when it made the line run
over 80 characters.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

The trf7970a driver uses the deprecated integer-based GPIO consumer
interface so convert it to use the new descriptor-based GPIO
consumer interface.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

The example DTS code for the trf7970a sets the GPIOs for the EN
and EN2 pins to active low when they are really active high so
correct the error.
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

The 'vin-voltage-override' DT property is used by the trf7970a
driver to override the voltage presented to the driver by the
regulator subsystem.  This is unnecessary as properly specifying
the regulator chain via DT properties will accomplish the same
thing.  Therefore, remove support for 'vin-voltage-override'.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

The last entry in the trf7970a_of_match[] table must be an empty
entry to demarcate the end of the table.  Currently, there is a
comment indicating this but it is obvious so remove the comment.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

The quirk indicated by the 'en2-rf-quirk' device tree property
is only relevant when there is a GPIO connected to the EN2 pin
of the trf7970a. This means we should only check for 'en2-rf-quirk'
when EN2 is specified in the 'ti,enable-gpios' property of the
device tree.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

As of commit ce69b95c ("NFC: Make EN2 pin optional in the
TRF7970A driver"), only the GPIO for the 'EN' enable pin needs
to be specified in the device tree so update the comments that
says both 'EN' and 'EN2' must be specified.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

When the trf7970a part has the bug related to 'en2-rf-quirk',
the GPIO connected to the EN2 pin will not be asserted by the
driver when powering up so it shouldn't be de-asserted when
powering down.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

Add Mark Greer as the maintainer of the trf7970a NFC driver.
Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>