Commit Graph
206 Commits
Author SHA1 Message Date
Kuniyuki IwashimaandJakub Kicinski d2492688bb nfc: nci: Fix race between rfkill and nci_unregister_device().
syzbot reported the splat below [0] without a repro.

It indicates that struct nci_dev.cmd_wq had been destroyed before
nci_close_device() was called via rfkill.

nci_dev.cmd_wq is only destroyed in nci_unregister_device(), which
(I think) was called from virtual_ncidev_close() when syzbot close()d
an fd of virtual_ncidev.

The problem is that nci_unregister_device() destroys nci_dev.cmd_wq
first and then calls nfc_unregister_device(), which removes the
device from rfkill by rfkill_unregister().

So, the device is still visible via rfkill even after nci_dev.cmd_wq
is destroyed.

Let's unregister the device from rfkill first in nci_unregister_device().

Note that we cannot call nfc_unregister_device() before
nci_close_device() because

  1) nfc_unregister_device() calls device_del() which frees
     all memory allocated by devm_kzalloc() and linked to
     ndev->conn_info_list

  2) nci_rx_work() could try to queue nci_conn_info to
     ndev->conn_info_list which could be leaked

Thus, nfc_unregister_device() is split into two functions so we
can remove rfkill interfaces only before nci_close_device().

[0]:
DEBUG_LOCKS_WARN_ON(1)
WARNING: kernel/locking/lockdep.c:238 at hlock_class kernel/locking/lockdep.c:238 [inline], CPU#0: syz.0.8675/6349
WARNING: kernel/locking/lockdep.c:238 at check_wait_context kernel/locking/lockdep.c:4854 [inline], CPU#0: syz.0.8675/6349
WARNING: kernel/locking/lockdep.c:238 at __lock_acquire+0x39d/0x2cf0 kernel/locking/lockdep.c:5187, CPU#0: syz.0.8675/6349
Modules linked in:
CPU: 0 UID: 0 PID: 6349 Comm: syz.0.8675 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
RIP: 0010:hlock_class kernel/locking/lockdep.c:238 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4854 [inline]
RIP: 0010:__lock_acquire+0x3a4/0x2cf0 kernel/locking/lockdep.c:5187
Code: 18 00 4c 8b 74 24 08 75 27 90 e8 17 f2 fc 02 85 c0 74 1c 83 3d 50 e0 4e 0e 00 75 13 48 8d 3d 43 f7 51 0e 48 c7 c6 8b 3a de 8d <67> 48 0f b9 3a 90 31 c0 0f b6 98 c4 00 00 00 41 8b 45 20 25 ff 1f
RSP: 0018:ffffc9000c767680 EFLAGS: 00010046
RAX: 0000000000000001 RBX: 0000000000040000 RCX: 0000000000080000
RDX: ffffc90013080000 RSI: ffffffff8dde3a8b RDI: ffffffff8ff24ca0
RBP: 0000000000000003 R08: ffffffff8fef35a3 R09: 1ffffffff1fde6b4
R10: dffffc0000000000 R11: fffffbfff1fde6b5 R12: 00000000000012a2
R13: ffff888030338ba8 R14: ffff888030338000 R15: ffff888030338b30
FS:  00007fa5995f66c0(0000) GS:ffff8881256f8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7e72f842d0 CR3: 00000000485a0000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 lock_acquire+0x106/0x330 kernel/locking/lockdep.c:5868
 touch_wq_lockdep_map+0xcb/0x180 kernel/workqueue.c:3940
 __flush_workqueue+0x14b/0x14f0 kernel/workqueue.c:3982
 nci_close_device+0x302/0x630 net/nfc/nci/core.c:567
 nci_dev_down+0x3b/0x50 net/nfc/nci/core.c:639
 nfc_dev_down+0x152/0x290 net/nfc/core.c:161
 nfc_rfkill_set_block+0x2d/0x100 net/nfc/core.c:179
 rfkill_set_block+0x1d2/0x440 net/rfkill/core.c:346
 rfkill_fop_write+0x461/0x5a0 net/rfkill/core.c:1301
 vfs_write+0x29a/0xb90 fs/read_write.c:684
 ksys_write+0x150/0x270 fs/read_write.c:738
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa59b39acb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa5995f6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fa59b615fa0 RCX: 00007fa59b39acb9
RDX: 0000000000000008 RSI: 0000200000000080 RDI: 0000000000000007
RBP: 00007fa59b408bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa59b616038 R14: 00007fa59b615fa0 R15: 00007ffc82218788
 </TASK>

Fixes: 6a2968aaf5 ("NFC: basic NCI protocol implementation")
Reported-by: syzbot+f9c5fd1a0874f9069dce@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/695e7f56.050a0220.1c677c.036c.GAE@google.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260127040411.494931-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-01-28 19:32:26 -08:00
Juraj ŠarinayandJakub Kicinski 21f82062d0 net: nfc: nci: Increase NCI_DATA_TIMEOUT to 3000 ms
An exchange with a NFC target must complete within NCI_DATA_TIMEOUT.
A delay of 700 ms is not sufficient for cryptographic operations on smart
cards. CardOS 6.0 may need up to 1.3 seconds to perform 256-bit ECDH
or 3072-bit RSA. To prevent brute-force attacks, passports and similar
documents introduce even longer delays into access control protocols
(BAC/PACE).

The timeout should be higher, but not too much. The expiration allows
us to detect that a NFC target has disappeared.

Signed-off-by: Juraj Šarinay <juraj@sarinay.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20250902113630.62393-1-juraj@sarinay.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-03 17:02:12 -07:00
Juraj ŠarinayandPaolo Abeni 9907cda95f net: nfc: Propagate ISO14443 type A target ATS to userspace via netlink
Add a 20-byte field ats to struct nfc_target and expose it as
NFC_ATTR_TARGET_ATS via the netlink interface. The payload contains
'historical bytes' that help to distinguish cards from one another.
The information is commonly used to assemble an emulated ATR similar
to that reported by smart cards with contacts.

Add a 20-byte field target_ats to struct nci_dev to hold the payload
obtained in nci_rf_intf_activated_ntf_packet() and copy it to over to
nfc_target.ats in nci_activate_target(). The approach is similar
to the handling of 'general bytes' within ATR_RES.

Replace the hard-coded size of rats_res within struct
activation_params_nfca_poll_iso_dep by the equal constant NFC_ATS_MAXSIZE
now defined in nfc.h

Within NCI, the information corresponds to the 'RATS Response' activation
parameter that omits the initial length byte TL. This loses no
information and is consistent with our handling of SENSB_RES that
also drops the first (constant) byte.

Tested with nxp_nci_i2c on a few type A targets including an
ICAO 9303 compliant passport.

I refrain from the corresponding change to digital_in_recv_ats()
to have the few drivers based on digital.h fill nfc_target.ats,
as I have no way to test it. That class of drivers appear not to set
NFC_ATTR_TARGET_SENSB_RES either. Consider a separate patch to propagate
(all) the parameters.

Signed-off-by: Juraj Šarinay <juraj@sarinay.com>
Link: https://patch.msgid.link/20241103124525.8392-1-juraj@sarinay.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-11-07 10:21:58 +01:00
Simon HormanandJakub Kicinski 10d0749a38 NFC: Correct spelling in headers
Correct spelling in NFC headers.
As reported by codespell.

Signed-off-by: Simon Horman <horms@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://patch.msgid.link/20240822-net-spell-v1-8-3a98971ce2d2@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-26 09:37:23 -07:00
Ricardo B. MarliereandJakub Kicinski e556001169 nfc: core: make nfc_class constant
Since commit 43a7206b09 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the nfc_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240302-class_cleanup-net-next-v1-6-8fa378595b93@marliere.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-05 11:21:18 -08:00
Lin MaandJakub Kicinski 48b71a9e66 NFC: add NCI_UNREG flag to eliminate the race
There are two sites that calls queue_work() after the
destroy_workqueue() and lead to possible UAF.

The first site is nci_send_cmd(), which can happen after the
nci_close_device as below

nfcmrvl_nci_unregister_dev   |  nfc_genl_dev_up
  nci_close_device           |
    flush_workqueue          |
    del_timer_sync           |
  nci_unregister_device      |    nfc_get_device
    destroy_workqueue        |    nfc_dev_up
    nfc_unregister_device    |      nci_dev_up
      device_del             |        nci_open_device
                             |          __nci_request
                             |            nci_send_cmd
                             |              queue_work !!!

Another site is nci_cmd_timer, awaked by the nci_cmd_work from the
nci_send_cmd.

  ...                        |  ...
  nci_unregister_device      |  queue_work
    destroy_workqueue        |
    nfc_unregister_device    |  ...
      device_del             |  nci_cmd_work
                             |  mod_timer
                             |  ...
                             |  nci_cmd_timer
                             |    queue_work !!!

For the above two UAF, the root cause is that the nfc_dev_up can race
between the nci_unregister_device routine. Therefore, this patch
introduce NCI_UNREG flag to easily eliminate the possible race. In
addition, the mutex_lock in nci_close_device can act as a barrier.

Signed-off-by: Lin Ma <linma@zju.edu.cn>
Fixes: 6a2968aaf5 ("NFC: basic NCI protocol implementation")
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211116152732.19238-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-17 20:17:05 -08:00
Krzysztof KozlowskiandDavid S. Miller 35d7a6f1fb nfc: hci: pass callback data param as pointer in nci_request()
The nci_request() receives a callback function and unsigned long data
argument "opt" which is passed to the callback.  Almost all of the
nci_request() callers pass pointer to a stack variable as data argument.
Only few pass scalar value (e.g. u8).

All such callbacks do not modify passed data argument and in previous
commit they were made as const.  However passing pointers via unsigned
long removes the const annotation.  The callback could simply cast
unsigned long to a pointer to writeable memory.

Use "const void *" as type of this "opt" argument to solve this and
prevent modifying the pointed contents.  This is also consistent with
generic pattern of passing data arguments - via "void *".  In few places
which pass scalar values, use casts via "unsigned long" to suppress any
warnings.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-02 15:11:37 +01:00
Krzysztof KozlowskiandJakub Kicinski ddecf5556f nfc: nci: constify several pointers to u8, sk_buff and other structs
Several functions receive pointers to u8, sk_buff or other structs 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.

This makes const also data passed as "unsigned long opt" argument to
nci_request() function.  Usual flow for such functions is:
1. Receive "u8 *" and store it (the pointer) in a structure
   allocated on stack (e.g. struct nci_set_config_param),
2. Call nci_request() or __nci_request() passing a callback function an
   the pointer to the structure via an "unsigned long opt",
3. nci_request() calls the callback which dereferences "unsigned long
   opt" in a read-only way.

This converts all above paths to use proper pointer to const data, so
entire flow is safer.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-07-30 17:22:52 +02:00
Krzysztof KozlowskiandJakub Kicinski 3df40eb3a2 nfc: constify several pointers to u8, char and sk_buff
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>
2021-07-30 17:22:52 +02:00
Krzysztof KozlowskiandDavid S. Miller dd8987a394 nfc: constify passed nfc_dev
The struct nfc_dev is not modified by nfc_get_drvdata() and
nfc_device_name() so it can be made a const.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-29 12:28:02 +01:00
Krzysztof KozlowskiandDavid S. Miller 7186aac9c2 nfc: constify nfc_digital_ops
Neither the core nor the drivers modify the passed pointer to struct
nfc_digital_ops, so make it a pointer to const for correctness and safety.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-25 09:21:21 +01:00
Krzysztof KozlowskiandDavid S. Miller 094c45c84d nfc: constify nfc_hci_ops
Neither the core nor the drivers modify the passed pointer to struct
nfc_hci_ops, so make it a pointer to const for correctness and safety.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-25 09:21:21 +01:00
Krzysztof KozlowskiandDavid S. Miller f6c802a726 nfc: constify nfc_ops
Neither the core nor the drivers modify the passed pointer to struct
nfc_ops, so make it a pointer to const for correctness and safety.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-25 09:21:21 +01:00
Krzysztof KozlowskiandDavid S. Miller 15944ad2e5 nfc: constify pointer to nfc_vendor_cmd
Neither the core nor the drivers modify the passed pointer to struct
nfc_vendor_cmd, so make it a pointer to const for correctness and
safety.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-25 09:21:21 +01:00
Krzysztof KozlowskiandDavid S. Miller cb8caa3c6c nfc: constify nci_driver_ops (prop_ops and core_ops)
Neither the core nor the drivers modify the passed pointer to struct
nci_driver_ops (consisting of function pointers), so make it a pointer
to const for correctness and safety.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-25 09:21:21 +01:00
Krzysztof KozlowskiandDavid S. Miller b9c28286d8 nfc: constify nci_ops
The struct nci_ops is modified by NFC core in only one case:
nci_allocate_device() receives too many proprietary commands (prop_ops)
to configure.  This is a build time known constrain, so a graceful
handling of such case is not necessary.

Instead, fail the nci_allocate_device() and add BUILD_BUG_ON() to places
which set these.

This allows to constify the struct nci_ops (consisting of function
pointers) for correctness and safety.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-25 09:21:20 +01:00
Krzysztof KozlowskiandDavid S. Miller 48d5440393 nfc: constify payload argument in nci_send_cmd()
The nci_send_cmd() payload argument is passed directly to skb_put_data()
which already accepts a pointer to const, so make it const as well for
correctness and safety.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-25 09:21:20 +01:00
Dongliang MuandDavid S. Miller e0652f8bb4 NFC: nci: fix memory leak in nci_allocate_device
nfcmrvl_disconnect fails to free the hci_dev field in struct nci_dev.
Fix this by freeing hci_dev in nci_free_device.

BUG: memory leak
unreferenced object 0xffff888111ea6800 (size 1024):
  comm "kworker/1:0", pid 19, jiffies 4294942308 (age 13.580s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 60 fd 0c 81 88 ff ff  .........`......
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<000000004bc25d43>] kmalloc include/linux/slab.h:552 [inline]
    [<000000004bc25d43>] kzalloc include/linux/slab.h:682 [inline]
    [<000000004bc25d43>] nci_hci_allocate+0x21/0xd0 net/nfc/nci/hci.c:784
    [<00000000c59cff92>] nci_allocate_device net/nfc/nci/core.c:1170 [inline]
    [<00000000c59cff92>] nci_allocate_device+0x10b/0x160 net/nfc/nci/core.c:1132
    [<00000000006e0a8e>] nfcmrvl_nci_register_dev+0x10a/0x1c0 drivers/nfc/nfcmrvl/main.c:153
    [<000000004da1b57e>] nfcmrvl_probe+0x223/0x290 drivers/nfc/nfcmrvl/usb.c:345
    [<00000000d506aed9>] usb_probe_interface+0x177/0x370 drivers/usb/core/driver.c:396
    [<00000000bc632c92>] really_probe+0x159/0x4a0 drivers/base/dd.c:554
    [<00000000f5009125>] driver_probe_device+0x84/0x100 drivers/base/dd.c:740
    [<000000000ce658ca>] __device_attach_driver+0xee/0x110 drivers/base/dd.c:846
    [<000000007067d05f>] bus_for_each_drv+0xb7/0x100 drivers/base/bus.c:431
    [<00000000f8e13372>] __device_attach+0x122/0x250 drivers/base/dd.c:914
    [<000000009cf68860>] bus_probe_device+0xc6/0xe0 drivers/base/bus.c:491
    [<00000000359c965a>] device_add+0x5be/0xc30 drivers/base/core.c:3109
    [<00000000086e4bd3>] usb_set_configuration+0x9d9/0xb90 drivers/usb/core/message.c:2164
    [<00000000ca036872>] usb_generic_driver_probe+0x8c/0xc0 drivers/usb/core/generic.c:238
    [<00000000d40d36f6>] usb_probe_device+0x5c/0x140 drivers/usb/core/driver.c:293
    [<00000000bc632c92>] really_probe+0x159/0x4a0 drivers/base/dd.c:554

Reported-by: syzbot+19bcfc64a8df1318d1c3@syzkaller.appspotmail.com
Fixes: 11f54f2286 ("NFC: nci: Add HCI over NCI protocol support")
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-05-17 13:56:29 -07:00
Jiri SlabyandGreg Kroah-Hartman c2a5a45c02 net: nfc: nci: drop nci_uart_ops::recv_buf
There is noone setting nci_uart_ops::recv_buf, so the default one
(nci_uart_default_recv_buf) is always used. So drop this hook, move
nci_uart_default_recv_buf before the use in nci_uart_tty_receive and
remove unused parameter flags.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20210302062214.29627-16-jslaby@suse.cz
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-10 09:34:07 +01:00
Bongsu JeonandJakub Kicinski bcd684aace net/nfc/nci: Support NCI 2.x initial sequence
implement the NCI 2.x initial sequence to support NCI 2.x NFCC.
Since NCI 2.0, CORE_RESET and CORE_INIT sequence have been changed.
If NFCEE supports NCI 2.x, then NCI 2.x initial sequence will work.

In NCI 1.0, Initial sequence and payloads are as below:
(DH)                     (NFCC)
 |  -- CORE_RESET_CMD --> |
 |  <-- CORE_RESET_RSP -- |
 |  -- CORE_INIT_CMD -->  |
 |  <-- CORE_INIT_RSP --  |
 CORE_RESET_RSP payloads are Status, NCI version, Configuration Status.
 CORE_INIT_CMD payloads are empty.
 CORE_INIT_RSP payloads are Status, NFCC Features,
    Number of Supported RF Interfaces, Supported RF Interface,
    Max Logical Connections, Max Routing table Size,
    Max Control Packet Payload Size, Max Size for Large Parameters,
    Manufacturer ID, Manufacturer Specific Information.

In NCI 2.0, Initial Sequence and Parameters are as below:
(DH)                     (NFCC)
 |  -- CORE_RESET_CMD --> |
 |  <-- CORE_RESET_RSP -- |
 |  <-- CORE_RESET_NTF -- |
 |  -- CORE_INIT_CMD -->  |
 |  <-- CORE_INIT_RSP --  |
 CORE_RESET_RSP payloads are Status.
 CORE_RESET_NTF payloads are Reset Trigger,
    Configuration Status, NCI Version, Manufacturer ID,
    Manufacturer Specific Information Length,
    Manufacturer Specific Information.
 CORE_INIT_CMD payloads are Feature1, Feature2.
 CORE_INIT_RSP payloads are Status, NFCC Features,
    Max Logical Connections, Max Routing Table Size,
    Max Control Packet Payload Size,
    Max Data Packet Payload Size of the Static HCI Connection,
    Number of Credits of the Static HCI Connection,
    Max NFC-V RF Frame Size, Number of Supported RF Interfaces,
    Supported RF Interfaces.

Signed-off-by: Bongsu Jeon <bongsu.jeon@samsung.com>
Link: https://lore.kernel.org/r/20201202223147.3472-1-bongsu.jeon@samsung.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-04 17:47:35 -08:00
Gustavo A. R. SilvaandDavid S. Miller da60fbe7ef NFC: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-27 12:06:20 -08:00
Thomas GleixnerandGreg Kroah-Hartman caab277b1d treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234
Based on 1 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 version 2 as
  published by the free software foundation 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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:07 +02:00
Thomas GleixnerandGreg Kroah-Hartman 46fe777164 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 399
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation 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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 33 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531081038.745679586@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:37:12 +02:00
Thomas GleixnerandGreg Kroah-Hartman 2025cf9e19 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 288
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope 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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 263 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.208660670@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:37 +02:00
Thomas GleixnerandGreg Kroah-Hartman 1ccea77e2a treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13
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>
2019-05-21 11:28:45 +02:00