This commit fixes several use-after-free that caused by function
nfc_llcp_find_local(). For example, one UAF can happen when below buggy
time window occurs.
// nfc_genl_llc_get_params | // nfc_unregister_device
|
dev = nfc_get_device(idx); | device_lock(...)
if (!dev) | dev->shutting_down = true;
return -ENODEV; | device_unlock(...);
|
device_lock(...); | // nfc_llcp_unregister_device
| nfc_llcp_find_local()
nfc_llcp_find_local(...); |
| local_cleanup()
if (!local) { |
rc = -ENODEV; | // nfc_llcp_local_put
goto exit; | kref_put(.., local_release)
} |
| // local_release
| list_del(&local->list)
// nfc_genl_send_params | kfree()
local->dev->idx !!!UAF!!! |
|
and the crash trace for the one of the discussed UAF like:
BUG: KASAN: slab-use-after-free in nfc_genl_llc_get_params+0x72f/0x780 net/nfc/netlink.c:1045
Read of size 8 at addr ffff888105b0e410 by task 20114
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x72/0xa0 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:319 [inline]
print_report+0xcc/0x620 mm/kasan/report.c:430
kasan_report+0xb2/0xe0 mm/kasan/report.c:536
nfc_genl_send_params net/nfc/netlink.c:999 [inline]
nfc_genl_llc_get_params+0x72f/0x780 net/nfc/netlink.c:1045
genl_family_rcv_msg_doit.isra.0+0x1ee/0x2e0 net/netlink/genetlink.c:968
genl_family_rcv_msg net/netlink/genetlink.c:1048 [inline]
genl_rcv_msg+0x503/0x7d0 net/netlink/genetlink.c:1065
netlink_rcv_skb+0x161/0x430 net/netlink/af_netlink.c:2548
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1076
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x644/0x900 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x934/0xe70 net/netlink/af_netlink.c:1913
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg+0x1b6/0x200 net/socket.c:747
____sys_sendmsg+0x6e9/0x890 net/socket.c:2501
___sys_sendmsg+0x110/0x1b0 net/socket.c:2555
__sys_sendmsg+0xf7/0x1d0 net/socket.c:2584
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3f/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7f34640a2389
RSP: 002b:00007f3463415168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f34641c1f80 RCX: 00007f34640a2389
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000006
RBP: 00007f34640ed493 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe38449ecf R14: 00007f3463415300 R15: 0000000000022000
</TASK>
Allocated by task 20116:
kasan_save_stack+0x22/0x50 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
____kasan_kmalloc mm/kasan/common.c:374 [inline]
__kasan_kmalloc+0x7f/0x90 mm/kasan/common.c:383
kmalloc include/linux/slab.h:580 [inline]
kzalloc include/linux/slab.h:720 [inline]
nfc_llcp_register_device+0x49/0xa40 net/nfc/llcp_core.c:1567
nfc_register_device+0x61/0x260 net/nfc/core.c:1124
nci_register_device+0x776/0xb20 net/nfc/nci/core.c:1257
virtual_ncidev_open+0x147/0x230 drivers/nfc/virtual_ncidev.c:148
misc_open+0x379/0x4a0 drivers/char/misc.c:165
chrdev_open+0x26c/0x780 fs/char_dev.c:414
do_dentry_open+0x6c4/0x12a0 fs/open.c:920
do_open fs/namei.c:3560 [inline]
path_openat+0x24fe/0x37e0 fs/namei.c:3715
do_filp_open+0x1ba/0x410 fs/namei.c:3742
do_sys_openat2+0x171/0x4c0 fs/open.c:1356
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x143/0x200 fs/open.c:1383
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3f/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x72/0xdc
Freed by task 20115:
kasan_save_stack+0x22/0x50 mm/kasan/common.c:45
kasan_set_track+0x25/0x30 mm/kasan/common.c:52
kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:521
____kasan_slab_free mm/kasan/common.c:236 [inline]
____kasan_slab_free mm/kasan/common.c:200 [inline]
__kasan_slab_free+0x10a/0x190 mm/kasan/common.c:244
kasan_slab_free include/linux/kasan.h:162 [inline]
slab_free_hook mm/slub.c:1781 [inline]
slab_free_freelist_hook mm/slub.c:1807 [inline]
slab_free mm/slub.c:3787 [inline]
__kmem_cache_free+0x7a/0x190 mm/slub.c:3800
local_release net/nfc/llcp_core.c:174 [inline]
kref_put include/linux/kref.h:65 [inline]
nfc_llcp_local_put net/nfc/llcp_core.c:182 [inline]
nfc_llcp_local_put net/nfc/llcp_core.c:177 [inline]
nfc_llcp_unregister_device+0x206/0x290 net/nfc/llcp_core.c:1620
nfc_unregister_device+0x160/0x1d0 net/nfc/core.c:1179
virtual_ncidev_close+0x52/0xa0 drivers/nfc/virtual_ncidev.c:163
__fput+0x252/0xa20 fs/file_table.c:321
task_work_run+0x174/0x270 kernel/task_work.c:179
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
exit_to_user_mode_prepare+0x108/0x110 kernel/entry/common.c:204
__syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
syscall_exit_to_user_mode+0x21/0x50 kernel/entry/common.c:297
do_syscall_64+0x4c/0x90 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x72/0xdc
Last potentially related work creation:
kasan_save_stack+0x22/0x50 mm/kasan/common.c:45
__kasan_record_aux_stack+0x95/0xb0 mm/kasan/generic.c:491
kvfree_call_rcu+0x29/0xa80 kernel/rcu/tree.c:3328
drop_sysctl_table+0x3be/0x4e0 fs/proc/proc_sysctl.c:1735
unregister_sysctl_table.part.0+0x9c/0x190 fs/proc/proc_sysctl.c:1773
unregister_sysctl_table+0x24/0x30 fs/proc/proc_sysctl.c:1753
neigh_sysctl_unregister+0x5f/0x80 net/core/neighbour.c:3895
addrconf_notify+0x140/0x17b0 net/ipv6/addrconf.c:3684
notifier_call_chain+0xbe/0x210 kernel/notifier.c:87
call_netdevice_notifiers_info+0xb5/0x150 net/core/dev.c:1937
call_netdevice_notifiers_extack net/core/dev.c:1975 [inline]
call_netdevice_notifiers net/core/dev.c:1989 [inline]
dev_change_name+0x3c3/0x870 net/core/dev.c:1211
dev_ifsioc+0x800/0xf70 net/core/dev_ioctl.c:376
dev_ioctl+0x3d9/0xf80 net/core/dev_ioctl.c:542
sock_do_ioctl+0x160/0x260 net/socket.c:1213
sock_ioctl+0x3f9/0x670 net/socket.c:1316
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl fs/ioctl.c:856 [inline]
__x64_sys_ioctl+0x19e/0x210 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3f/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x72/0xdc
The buggy address belongs to the object at ffff888105b0e400
which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 16 bytes inside of
freed 1024-byte region [ffff888105b0e400, ffff888105b0e800)
The buggy address belongs to the physical page:
head:ffffea000416c200 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x200000000010200(slab|head|node=0|zone=2)
raw: 0200000000010200 ffff8881000430c0 ffffea00044c7010 ffffea0004510e10
raw: 0000000000000000 00000000000a000a 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888105b0e300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888105b0e380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888105b0e400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888105b0e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888105b0e500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
In summary, this patch solves those use-after-free by
1. Re-implement the nfc_llcp_find_local(). The current version does not
grab the reference when getting the local from the linked list. For
example, the llcp_sock_bind() gets the reference like below:
// llcp_sock_bind()
local = nfc_llcp_find_local(dev); // A
..... \
| raceable
..... /
llcp_sock->local = nfc_llcp_local_get(local); // B
There is an apparent race window that one can drop the reference
and free the local object fetched in (A) before (B) gets the reference.
2. Some callers of the nfc_llcp_find_local() do not grab the reference
at all. For example, the nfc_genl_llc_{{get/set}_params/sdreq} functions.
We add the nfc_llcp_local_put() for them. Moreover, we add the necessary
error handling function to put the reference.
3. Add the nfc_llcp_remove_local() helper. The local object is removed
from the linked list in local_release() when all reference is gone. This
patch removes it when nfc_llcp_unregister_device() is called.
Therefore, every caller of nfc_llcp_find_local() will get a reference
even when the nfc_llcp_unregister_device() is called. This promises no
use-after-free for the local object is ever possible.
Fixes: 52feb444a9 ("NFC: Extend netlink interface for LTO, RW, and MIUX parameters support")
Fixes: c7aa12252f ("NFC: Take a reference on the LLCP local pointer when creating a socket")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If sock->service_name is NULL, the local variable
service_name_tlv_length will not be assigned by nfc_llcp_build_tlv(),
later leading to using value frmo the stack. Smatch warning:
net/nfc/llcp_commands.c:442 nfc_llcp_send_connect() error: uninitialized symbol 'service_name_tlv_length'.
Fixes: de9e5aeb4f ("NFC: llcp: Fix usage of llcp_add_tlv()")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
ftrace is a preferred and standard way to debug entering and exiting
functions so drop useless debug prints.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Several functions receive pointers to u8, char or sk_buff but do not
modify the contents so make them const. This allows doing the same for
local variables and in total makes the code a little bit safer.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not see http www gnu org licenses
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details [based]
[from] [clk] [highbank] [c] you should have received a copy of the
gnu general public license along with this program if not see http
www gnu org licenses
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 355 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190519154041.837383322@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
syzbot is reporting stalls at nfc_llcp_send_ui_frame() [1]. This is
because nfc_llcp_send_ui_frame() is retrying the loop without any delay
when nonblocking nfc_alloc_send_skb() returned NULL.
Since there is no need to use MSG_DONTWAIT if we retry until
sock_alloc_send_pskb() succeeds, let's use blocking call.
Also, in case an unexpected error occurred, let's break the loop
if blocking nfc_alloc_send_skb() failed.
[1] https://syzkaller.appspot.com/bug?id=4a131cc571c3733e0eff6bc673f4e36ae48f19c6
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reported-by: syzbot <syzbot+d29d18215e477cfbfbdd@syzkaller.appspotmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The tlv_len is u8, so we need to limit the size of the SDP URI. Enforce
this both in the NLA policy and in the code that performs the allocation
and copy, to avoid writing past the end of the allocated buffer.
Fixes: d9b8d8e19b ("NFC: llcp: Service Name Lookup netlink interface")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
A common pattern with skb_put() is to just want to memcpy()
some data into the new space, introduce skb_put_data() for
this.
An spatch similar to the one for skb_put_zero() converts many
of the places using it:
@@
identifier p, p2;
expression len, skb, data;
type t, t2;
@@
(
-p = skb_put(skb, len);
+p = skb_put_data(skb, data, len);
|
-p = (t)skb_put(skb, len);
+p = skb_put_data(skb, data, len);
)
(
p2 = (t2)p;
-memcpy(p2, data, len);
|
-memcpy(p, data, len);
)
@@
type t, t2;
identifier p, p2;
expression skb, data;
@@
t *p;
...
(
-p = skb_put(skb, sizeof(t));
+p = skb_put_data(skb, data, sizeof(t));
|
-p = (t *)skb_put(skb, sizeof(t));
+p = skb_put_data(skb, data, sizeof(t));
)
(
p2 = (t2)p;
-memcpy(p2, data, sizeof(*p));
|
-memcpy(p, data, sizeof(*p));
)
@@
expression skb, len, data;
@@
-memcpy(skb_put(skb, len), data, len);
+skb_put_data(skb, data, len);
(again, manually post-processed to retain some comments)
Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Once copied into the sk_buff data area using llcp_add_tlv(), the
allocated TLVs must be freed.
With this patch nfc_llcp_send_connect() and nfc_llcp_send_cc() don't
return immediately on success and now free the allocated TLVs.
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
In functions using llcp_add_tlv(), a skb pointer could be set to NULL
and then reuse afterward.
With this patch, the skb pointer returned by llcp_add_tlv() is ignored
since it can only be the passed skb pointer or NULL when the passed TLV
is NULL. There is also no need to check for the TLV pointer as this is
done by llcp_add_tlv().
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
These two functions are called in sendmsg path, and the
'len' is passed from user-space, so we should not allow
malicious users to OOM kernel on purpose.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
John W. Linville says:
====================
pull request: wireless-next 2014-12-08
Please pull this last batch of pending wireless updates for the 3.19 tree...
For the wireless bits, Johannes says:
"This time I have Felix's no-status rate control work, which will allow
drivers to work better with rate control even if they don't have perfect
status reporting. In addition to this, a small hwsim fix from Patrik,
one of the regulatory patches from Arik, and a number of cleanups and
fixes I did myself.
Of note is a patch where I disable CFG80211_WEXT so that compatibility
is no longer selectable - this is intended as a wake-up call for anyone
who's still using it, and is still easily worked around (it's a one-line
patch) before we fully remove the code as well in the future."
For the Bluetooth bits, Johan says:
"Here's one more bluetooth-next pull request for 3.19:
- Minor cleanups for ieee802154 & mac802154
- Fix for the kernel warning with !TASK_RUNNING reported by Kirill A.
Shutemov
- Support for another ath3k device
- Fix for tracking link key based security level
- Device tree bindings for btmrvl + a state update fix
- Fix for wrong ACL flags on LE links"
And...
"In addition to the previous one this contains two more cleanups to
mac802154 as well as support for some new HCI features from the
Bluetooth 4.2 specification.
From the original request:
'Here's what should be the last bluetooth-next pull request for 3.19.
It's rather large but the majority of it is the Low Energy Secure
Connections feature that's part of the Bluetooth 4.2 specification. The
specification went public only this week so we couldn't publish the
corresponding code before that. The code itself can nevertheless be
considered fairly mature as it's been in development for over 6 months
and gone through several interoperability test events.
Besides LE SC the pull request contains an important fix for command
complete events for mgmt sockets which also fixes some leaks of hci_conn
objects when powering off or unplugging Bluetooth adapters.
A smaller feature that's part of the pull request is service discovery
support. This is like normal device discovery except that devices not
matching specific UUIDs or strong enough RSSI are filtered out.
Other changes that the pull request contains are firmware dump support
to the btmrvl driver, firmware download support for Broadcom BCM20702A0
variants, as well as some coding style cleanups in 6lowpan &
ieee802154/mac802154 code.'"
For the NFC bits, Samuel says:
"With this one we get:
- NFC digital improvements for DEP support: Chaining, NACK and ATN
support added.
- NCI improvements: Support for p2p target, SE IO operand addition,
SE operands extensions to support proprietary implementations, and
a few fixes.
- NFC HCI improvements: OPEN_PIPE and NOTIFY_ALL_CLEARED support,
and SE IO operand addition.
- A bunch of minor improvements and fixes for STMicro st21nfcb and
st21nfca"
For the iwlwifi bits, Emmanuel says:
"Major works are CSA and TDLS. On top of that I have a new
firmware API for scan and a few rate control improvements.
Johannes find a few tricks to improve our CPU utilization
and adds support for a new spin of 7265 called 7265D.
Along with this a few random things that don't stand out."
And...
"I deprecate here -8.ucode since -9 has been published long ago.
Along with that I have a new activity, we have now better
a infrastructure for firmware debugging. This will allow to
have configurable probes insides the firmware.
Luca continues his work on NetDetect, this feature is now
complete. All the rest is minor fixes here and there."
For the Atheros bits, Kalle says:
"Only ath10k changes this time and no major changes. Most visible are:
o new debugfs interface for runtime firmware debugging (Yanbo)
o fix shared WEP (Sujith)
o don't rebuild whenever kernel version changes (Johannes)
o lots of refactoring to make it easier to add new hw support (Michal)
There's also smaller fixes and improvements with no point of listing
here."
In addition, there are a few last minute updates to ath5k,
ath9k, brcmfmac, brcmsmac, mwifiex, rt2x00, rtlwifi, and wil6210.
Also included is a pull of the wireless tree to pick-up the fixes
originally included in "pull request: wireless 2014-12-03"...
Please let me know if there are problems!
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix warnings:
net/nfc/llcp_commands.c:421:14: warning: incorrect type in assignment (different base types)
net/nfc/llcp_commands.c:421:14: expected unsigned short [unsigned] [usertype] miux
net/nfc/llcp_commands.c:421:14: got restricted __be16
net/nfc/llcp_commands.c:477:14: warning: incorrect type in assignment (different base types)
net/nfc/llcp_commands.c:477:14: expected unsigned short [unsigned] [usertype] miux
net/nfc/llcp_commands.c:477:14: got restricted __be16
Procedure to reproduce:
make ARCH=x86_64 allmodconfig
make C=1 CF=-D__CHECK_ENDIAN__
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This allows for a more generic NFC sniffing by using SOCKPROTO_RAW
SOCK_RAW to read RAW NFC frames. This is for sniffing anything but LLCP
(HCI, NCI, etc...).
Signed-off-by: Hiren Tandel <hirent@marvell.com>
Signed-off-by: Rahul Tank <rahult@marvell.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
If MIUX is not present in CONNECT or CC use default MIU value (128)
instead of one announced durring link setup.
This was affecting Bluetooth handover with Android 4.3+ NCI stack.
Signed-off-by: Szymon Janc <szymon.janc@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
If sending was not completed due to low memory condition msg_data
was not free before returning from function.
Signed-off-by: Szymon Janc <szymon.janc@gmail.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Several files refer to an old address for the Free Software Foundation
in the file header comment. Resolve by replacing the address with
the URL <http://www.gnu.org/licenses/> so that we do not have to keep
updating the header comments anytime the address changes.
CC: linux-wireless@vger.kernel.org
CC: Lauro Ramos Venancio <lauro.venancio@openbossa.org>
CC: Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
CC: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
nfc_llcp_send_disconnect() already exists but is not used.
nfc_llcp_disconnect() naming is not consistent with other PDU
sending functions.
This patch removes nfc_llcp_send_disconnect() and renames
nfc_llcp_disconnect()
Signed-off-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
And stop making it optional. LLCP is a fundamental part of the NFC
specifications and making it optional does not make much sense.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Jakub Kicinski