<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-dev/net/nfc, branch linus/master</title>
<subtitle>Linux kernel development work - see feature branches</subtitle>
<id>https://git.zx2c4.com/linux-dev/atom/net/nfc?h=linus%2Fmaster</id>
<link rel='self' href='https://git.zx2c4.com/linux-dev/atom/net/nfc?h=linus%2Fmaster'/>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/'/>
<updated>2022-05-28T14:28:47Z</updated>
<entry>
<title>net: nfc: Directly use ida_alloc()/free()</title>
<updated>2022-05-28T14:28:47Z</updated>
<author>
<name>keliu</name>
<email>liuke94@huawei.com</email>
</author>
<published>2022-05-27T06:42:25Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=911799172d2f703cc14e9000c55d124d5e0a91a2'/>
<id>urn:sha1:911799172d2f703cc14e9000c55d124d5e0a91a2</id>
<content type='text'>
Use ida_alloc()/ida_free() instead of deprecated
ida_simple_get()/ida_simple_remove() .

Signed-off-by: keliu &lt;liuke94@huawei.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2022-05-19T18:23:59Z</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2022-05-19T18:23:59Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=d7e6f5836038eeac561411ed7a74e2a225a6c138'/>
<id>urn:sha1:d7e6f5836038eeac561411ed7a74e2a225a6c138</id>
<content type='text'>
drivers/net/ethernet/mellanox/mlx5/core/main.c
  b33886971dbc ("net/mlx5: Initialize flow steering during driver probe")
  40379a0084c2 ("net/mlx5_fpga: Drop INNOVA TLS support")
  f2b41b32cde8 ("net/mlx5: Remove ipsec_ops function table")
https://lore.kernel.org/all/20220519040345.6yrjromcdistu7vh@sx1/
  16d42d313350 ("net/mlx5: Drain fw_reset when removing device")
  8324a02c342a ("net/mlx5: Add exit route when waiting for FW")
https://lore.kernel.org/all/20220519114119.060ce014@canb.auug.org.au/

tools/testing/selftests/net/mptcp/mptcp_join.sh
  e274f7154008 ("selftests: mptcp: add subflow limits test-cases")
  b6e074e171bc ("selftests: mptcp: add infinite map testcase")
  5ac1d2d63451 ("selftests: mptcp: Add tests for userspace PM type")
https://lore.kernel.org/all/20220516111918.366d747f@canb.auug.org.au/

net/mptcp/options.c
  ba2c89e0ea74 ("mptcp: fix checksum byte order")
  1e39e5a32ad7 ("mptcp: infinite mapping sending")
  ea66758c1795 ("tcp: allow MPTCP to update the announced window")
https://lore.kernel.org/all/20220519115146.751c3a37@canb.auug.org.au/

net/mptcp/pm.c
  95d686517884 ("mptcp: fix subflow accounting on close")
  4d25247d3ae4 ("mptcp: bypass in-kernel PM restrictions for non-kernel PMs")
https://lore.kernel.org/all/20220516111435.72f35dca@canb.auug.org.au/

net/mptcp/subflow.c
  ae66fb2ba6c3 ("mptcp: Do TCP fallback on early DSS checksum failure")
  0348c690ed37 ("mptcp: add the fallback check")
  f8d4bcacff3b ("mptcp: infinite mapping receiving")
https://lore.kernel.org/all/20220519115837.380bb8d4@canb.auug.org.au/

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
</entry>
<entry>
<title>NFC: nci: fix sleep in atomic context bugs caused by nci_skb_alloc</title>
<updated>2022-05-18T00:55:53Z</updated>
<author>
<name>Duoming Zhou</name>
<email>duoming@zju.edu.cn</email>
</author>
<published>2022-05-17T01:25:30Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=23dd4581350d4ffa23d58976ec46408f8f4c1e16'/>
<id>urn:sha1:23dd4581350d4ffa23d58976ec46408f8f4c1e16</id>
<content type='text'>
There are sleep in atomic context bugs when the request to secure
element of st-nci is timeout. The root cause is that nci_skb_alloc
with GFP_KERNEL parameter is called in st_nci_se_wt_timeout which is
a timer handler. The call paths that could trigger bugs are shown below:

    (interrupt context 1)
st_nci_se_wt_timeout
  nci_hci_send_event
    nci_hci_send_data
      nci_skb_alloc(..., GFP_KERNEL) //may sleep

   (interrupt context 2)
st_nci_se_wt_timeout
  nci_hci_send_event
    nci_hci_send_data
      nci_send_data
        nci_queue_tx_data_frags
          nci_skb_alloc(..., GFP_KERNEL) //may sleep

This patch changes allocation mode of nci_skb_alloc from GFP_KERNEL to
GFP_ATOMIC in order to prevent atomic context sleeping. The GFP_ATOMIC
flag makes memory allocation operation could be used in atomic context.

Fixes: ed06aeefdac3 ("nfc: st-nci: Rename st21nfcb to st-nci")
Signed-off-by: Duoming Zhou &lt;duoming@zju.edu.cn&gt;
Reviewed-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Link: https://lore.kernel.org/r/20220517012530.75714-1-duoming@zju.edu.cn
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2022-05-05T20:03:18Z</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2022-05-05T20:03:18Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=c8227d568ddf2f38a8806fdcd2e20b9e11747d9a'/>
<id>urn:sha1:c8227d568ddf2f38a8806fdcd2e20b9e11747d9a</id>
<content type='text'>
tools/testing/selftests/net/forwarding/Makefile
  f62c5acc800e ("selftests/net/forwarding: add missing tests to Makefile")
  50fe062c806e ("selftests: forwarding: new test, verify host mdb entries")
https://lore.kernel.org/all/20220502111539.0b7e4621@canb.auug.org.au/

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
</entry>
<entry>
<title>NFC: netlink: fix sleep in atomic bug when firmware download timeout</title>
<updated>2022-05-05T08:18:15Z</updated>
<author>
<name>Duoming Zhou</name>
<email>duoming@zju.edu.cn</email>
</author>
<published>2022-05-04T05:58:47Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=4071bf121d59944d5cd2238de0642f3d7995a997'/>
<id>urn:sha1:4071bf121d59944d5cd2238de0642f3d7995a997</id>
<content type='text'>
There are sleep in atomic bug that could cause kernel panic during
firmware download process. The root cause is that nlmsg_new with
GFP_KERNEL parameter is called in fw_dnld_timeout which is a timer
handler. The call trace is shown below:

BUG: sleeping function called from invalid context at include/linux/sched/mm.h:265
Call Trace:
kmem_cache_alloc_node
__alloc_skb
nfc_genl_fw_download_done
call_timer_fn
__run_timers.part.0
run_timer_softirq
__do_softirq
...

The nlmsg_new with GFP_KERNEL parameter may sleep during memory
allocation process, and the timer handler is run as the result of
a "software interrupt" that should not call any other function
that could sleep.

This patch changes allocation mode of netlink message from GFP_KERNEL
to GFP_ATOMIC in order to prevent sleep in atomic bug. The GFP_ATOMIC
flag makes memory allocation operation could be used in atomic context.

Fixes: 9674da8759df ("NFC: Add firmware upload netlink command")
Fixes: 9ea7187c53f6 ("NFC: netlink: Rename CMD_FW_UPLOAD to CMD_FW_DOWNLOAD")
Signed-off-by: Duoming Zhou &lt;duoming@zju.edu.cn&gt;
Reviewed-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Link: https://lore.kernel.org/r/20220504055847.38026-1-duoming@zju.edu.cn
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</content>
</entry>
<entry>
<title>nfc: replace improper check device_is_registered() in netlink related functions</title>
<updated>2022-05-01T12:26:05Z</updated>
<author>
<name>Duoming Zhou</name>
<email>duoming@zju.edu.cn</email>
</author>
<published>2022-04-29T12:45:50Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=da5c0f119203ad9728920456a0f52a6d850c01cd'/>
<id>urn:sha1:da5c0f119203ad9728920456a0f52a6d850c01cd</id>
<content type='text'>
The device_is_registered() in nfc core is used to check whether
nfc device is registered in netlink related functions such as
nfc_fw_download(), nfc_dev_up() and so on. Although device_is_registered()
is protected by device_lock, there is still a race condition between
device_del() and device_is_registered(). The root cause is that
kobject_del() in device_del() is not protected by device_lock.

   (cleanup task)         |     (netlink task)
                          |
nfc_unregister_device     | nfc_fw_download
 device_del               |  device_lock
  ...                     |   if (!device_is_registered)//(1)
  kobject_del//(2)        |   ...
 ...                      |  device_unlock

The device_is_registered() returns the value of state_in_sysfs and
the state_in_sysfs is set to zero in kobject_del(). If we pass check in
position (1), then set zero in position (2). As a result, the check
in position (1) is useless.

This patch uses bool variable instead of device_is_registered() to judge
whether the nfc device is registered, which is well synchronized.

Fixes: 3e256b8f8dfa ("NFC: add nfc subsystem core")
Signed-off-by: Duoming Zhou &lt;duoming@zju.edu.cn&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2022-04-15T07:26:00Z</updated>
<author>
<name>Paolo Abeni</name>
<email>pabeni@redhat.com</email>
</author>
<published>2022-04-15T07:26:00Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=edf45f007a31e86738f6be3065591ddad94477d1'/>
<id>urn:sha1:edf45f007a31e86738f6be3065591ddad94477d1</id>
<content type='text'>
</content>
</entry>
<entry>
<title>nfc: nci: add flush_workqueue to prevent uaf</title>
<updated>2022-04-13T13:44:44Z</updated>
<author>
<name>Lin Ma</name>
<email>linma@zju.edu.cn</email>
</author>
<published>2022-04-12T16:04:30Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=ef27324e2cb7bb24542d6cb2571740eefe6b00dc'/>
<id>urn:sha1:ef27324e2cb7bb24542d6cb2571740eefe6b00dc</id>
<content type='text'>
Our detector found a concurrent use-after-free bug when detaching an
NCI device. The main reason for this bug is the unexpected scheduling
between the used delayed mechanism (timer and workqueue).

The race can be demonstrated below:

Thread-1                           Thread-2
                                 | nci_dev_up()
                                 |   nci_open_device()
                                 |     __nci_request(nci_reset_req)
                                 |       nci_send_cmd
                                 |         queue_work(cmd_work)
nci_unregister_device()          |
  nci_close_device()             | ...
    del_timer_sync(cmd_timer)[1] |
...                              | Worker
nci_free_device()                | nci_cmd_work()
  kfree(ndev)[3]                 |   mod_timer(cmd_timer)[2]

In short, the cleanup routine thought that the cmd_timer has already
been detached by [1] but the mod_timer can re-attach the timer [2], even
it is already released [3], resulting in UAF.

This UAF is easy to trigger, crash trace by POC is like below

[   66.703713] ==================================================================
[   66.703974] BUG: KASAN: use-after-free in enqueue_timer+0x448/0x490
[   66.703974] Write of size 8 at addr ffff888009fb7058 by task kworker/u4:1/33
[   66.703974]
[   66.703974] CPU: 1 PID: 33 Comm: kworker/u4:1 Not tainted 5.18.0-rc2 #5
[   66.703974] Workqueue: nfc2_nci_cmd_wq nci_cmd_work
[   66.703974] Call Trace:
[   66.703974]  &lt;TASK&gt;
[   66.703974]  dump_stack_lvl+0x57/0x7d
[   66.703974]  print_report.cold+0x5e/0x5db
[   66.703974]  ? enqueue_timer+0x448/0x490
[   66.703974]  kasan_report+0xbe/0x1c0
[   66.703974]  ? enqueue_timer+0x448/0x490
[   66.703974]  enqueue_timer+0x448/0x490
[   66.703974]  __mod_timer+0x5e6/0xb80
[   66.703974]  ? mark_held_locks+0x9e/0xe0
[   66.703974]  ? try_to_del_timer_sync+0xf0/0xf0
[   66.703974]  ? lockdep_hardirqs_on_prepare+0x17b/0x410
[   66.703974]  ? queue_work_on+0x61/0x80
[   66.703974]  ? lockdep_hardirqs_on+0xbf/0x130
[   66.703974]  process_one_work+0x8bb/0x1510
[   66.703974]  ? lockdep_hardirqs_on_prepare+0x410/0x410
[   66.703974]  ? pwq_dec_nr_in_flight+0x230/0x230
[   66.703974]  ? rwlock_bug.part.0+0x90/0x90
[   66.703974]  ? _raw_spin_lock_irq+0x41/0x50
[   66.703974]  worker_thread+0x575/0x1190
[   66.703974]  ? process_one_work+0x1510/0x1510
[   66.703974]  kthread+0x2a0/0x340
[   66.703974]  ? kthread_complete_and_exit+0x20/0x20
[   66.703974]  ret_from_fork+0x22/0x30
[   66.703974]  &lt;/TASK&gt;
[   66.703974]
[   66.703974] Allocated by task 267:
[   66.703974]  kasan_save_stack+0x1e/0x40
[   66.703974]  __kasan_kmalloc+0x81/0xa0
[   66.703974]  nci_allocate_device+0xd3/0x390
[   66.703974]  nfcmrvl_nci_register_dev+0x183/0x2c0
[   66.703974]  nfcmrvl_nci_uart_open+0xf2/0x1dd
[   66.703974]  nci_uart_tty_ioctl+0x2c3/0x4a0
[   66.703974]  tty_ioctl+0x764/0x1310
[   66.703974]  __x64_sys_ioctl+0x122/0x190
[   66.703974]  do_syscall_64+0x3b/0x90
[   66.703974]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[   66.703974]
[   66.703974] Freed by task 406:
[   66.703974]  kasan_save_stack+0x1e/0x40
[   66.703974]  kasan_set_track+0x21/0x30
[   66.703974]  kasan_set_free_info+0x20/0x30
[   66.703974]  __kasan_slab_free+0x108/0x170
[   66.703974]  kfree+0xb0/0x330
[   66.703974]  nfcmrvl_nci_unregister_dev+0x90/0xd0
[   66.703974]  nci_uart_tty_close+0xdf/0x180
[   66.703974]  tty_ldisc_kill+0x73/0x110
[   66.703974]  tty_ldisc_hangup+0x281/0x5b0
[   66.703974]  __tty_hangup.part.0+0x431/0x890
[   66.703974]  tty_release+0x3a8/0xc80
[   66.703974]  __fput+0x1f0/0x8c0
[   66.703974]  task_work_run+0xc9/0x170
[   66.703974]  exit_to_user_mode_prepare+0x194/0x1a0
[   66.703974]  syscall_exit_to_user_mode+0x19/0x50
[   66.703974]  do_syscall_64+0x48/0x90
[   66.703974]  entry_SYSCALL_64_after_hwframe+0x44/0xae

To fix the UAF, this patch adds flush_workqueue() to ensure the
nci_cmd_work is finished before the following del_timer_sync.
This combination will promise the timer is actually detached.

Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation")
Signed-off-by: Lin Ma &lt;linma@zju.edu.cn&gt;
Reviewed-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>NFC: NULL out the dev-&gt;rfkill to prevent UAF</title>
<updated>2022-04-13T11:22:05Z</updated>
<author>
<name>Lin Ma</name>
<email>linma@zju.edu.cn</email>
</author>
<published>2022-04-12T05:32:08Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=1b0e81416a24d6e9b8c2341e22e8bf48f8b8bfc9'/>
<id>urn:sha1:1b0e81416a24d6e9b8c2341e22e8bf48f8b8bfc9</id>
<content type='text'>
Commit 3e3b5dfcd16a ("NFC: reorder the logic in nfc_{un,}register_device")
assumes the device_is_registered() in function nfc_dev_up() will help
to check when the rfkill is unregistered. However, this check only
take effect when device_del(&amp;dev-&gt;dev) is done in nfc_unregister_device().
Hence, the rfkill object is still possible be dereferenced.

The crash trace in latest kernel (5.18-rc2):

[   68.760105] ==================================================================
[   68.760330] BUG: KASAN: use-after-free in __lock_acquire+0x3ec1/0x6750
[   68.760756] Read of size 8 at addr ffff888009c93018 by task fuzz/313
[   68.760756]
[   68.760756] CPU: 0 PID: 313 Comm: fuzz Not tainted 5.18.0-rc2 #4
[   68.760756] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[   68.760756] Call Trace:
[   68.760756]  &lt;TASK&gt;
[   68.760756]  dump_stack_lvl+0x57/0x7d
[   68.760756]  print_report.cold+0x5e/0x5db
[   68.760756]  ? __lock_acquire+0x3ec1/0x6750
[   68.760756]  kasan_report+0xbe/0x1c0
[   68.760756]  ? __lock_acquire+0x3ec1/0x6750
[   68.760756]  __lock_acquire+0x3ec1/0x6750
[   68.760756]  ? lockdep_hardirqs_on_prepare+0x410/0x410
[   68.760756]  ? register_lock_class+0x18d0/0x18d0
[   68.760756]  lock_acquire+0x1ac/0x4f0
[   68.760756]  ? rfkill_blocked+0xe/0x60
[   68.760756]  ? lockdep_hardirqs_on_prepare+0x410/0x410
[   68.760756]  ? mutex_lock_io_nested+0x12c0/0x12c0
[   68.760756]  ? nla_get_range_signed+0x540/0x540
[   68.760756]  ? _raw_spin_lock_irqsave+0x4e/0x50
[   68.760756]  _raw_spin_lock_irqsave+0x39/0x50
[   68.760756]  ? rfkill_blocked+0xe/0x60
[   68.760756]  rfkill_blocked+0xe/0x60
[   68.760756]  nfc_dev_up+0x84/0x260
[   68.760756]  nfc_genl_dev_up+0x90/0xe0
[   68.760756]  genl_family_rcv_msg_doit+0x1f4/0x2f0
[   68.760756]  ? genl_family_rcv_msg_attrs_parse.constprop.0+0x230/0x230
[   68.760756]  ? security_capable+0x51/0x90
[   68.760756]  genl_rcv_msg+0x280/0x500
[   68.760756]  ? genl_get_cmd+0x3c0/0x3c0
[   68.760756]  ? lock_acquire+0x1ac/0x4f0
[   68.760756]  ? nfc_genl_dev_down+0xe0/0xe0
[   68.760756]  ? lockdep_hardirqs_on_prepare+0x410/0x410
[   68.760756]  netlink_rcv_skb+0x11b/0x340
[   68.760756]  ? genl_get_cmd+0x3c0/0x3c0
[   68.760756]  ? netlink_ack+0x9c0/0x9c0
[   68.760756]  ? netlink_deliver_tap+0x136/0xb00
[   68.760756]  genl_rcv+0x1f/0x30
[   68.760756]  netlink_unicast+0x430/0x710
[   68.760756]  ? memset+0x20/0x40
[   68.760756]  ? netlink_attachskb+0x740/0x740
[   68.760756]  ? __build_skb_around+0x1f4/0x2a0
[   68.760756]  netlink_sendmsg+0x75d/0xc00
[   68.760756]  ? netlink_unicast+0x710/0x710
[   68.760756]  ? netlink_unicast+0x710/0x710
[   68.760756]  sock_sendmsg+0xdf/0x110
[   68.760756]  __sys_sendto+0x19e/0x270
[   68.760756]  ? __ia32_sys_getpeername+0xa0/0xa0
[   68.760756]  ? fd_install+0x178/0x4c0
[   68.760756]  ? fd_install+0x195/0x4c0
[   68.760756]  ? kernel_fpu_begin_mask+0x1c0/0x1c0
[   68.760756]  __x64_sys_sendto+0xd8/0x1b0
[   68.760756]  ? lockdep_hardirqs_on+0xbf/0x130
[   68.760756]  ? syscall_enter_from_user_mode+0x1d/0x50
[   68.760756]  do_syscall_64+0x3b/0x90
[   68.760756]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[   68.760756] RIP: 0033:0x7f67fb50e6b3
...
[   68.760756] RSP: 002b:00007f67fa91fe90 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
[   68.760756] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f67fb50e6b3
[   68.760756] RDX: 000000000000001c RSI: 0000559354603090 RDI: 0000000000000003
[   68.760756] RBP: 00007f67fa91ff00 R08: 00007f67fa91fedc R09: 000000000000000c
[   68.760756] R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffe824d496e
[   68.760756] R13: 00007ffe824d496f R14: 00007f67fa120000 R15: 0000000000000003

[   68.760756]  &lt;/TASK&gt;
[   68.760756]
[   68.760756] Allocated by task 279:
[   68.760756]  kasan_save_stack+0x1e/0x40
[   68.760756]  __kasan_kmalloc+0x81/0xa0
[   68.760756]  rfkill_alloc+0x7f/0x280
[   68.760756]  nfc_register_device+0xa3/0x1a0
[   68.760756]  nci_register_device+0x77a/0xad0
[   68.760756]  nfcmrvl_nci_register_dev+0x20b/0x2c0
[   68.760756]  nfcmrvl_nci_uart_open+0xf2/0x1dd
[   68.760756]  nci_uart_tty_ioctl+0x2c3/0x4a0
[   68.760756]  tty_ioctl+0x764/0x1310
[   68.760756]  __x64_sys_ioctl+0x122/0x190
[   68.760756]  do_syscall_64+0x3b/0x90
[   68.760756]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[   68.760756]
[   68.760756] Freed by task 314:
[   68.760756]  kasan_save_stack+0x1e/0x40
[   68.760756]  kasan_set_track+0x21/0x30
[   68.760756]  kasan_set_free_info+0x20/0x30
[   68.760756]  __kasan_slab_free+0x108/0x170
[   68.760756]  kfree+0xb0/0x330
[   68.760756]  device_release+0x96/0x200
[   68.760756]  kobject_put+0xf9/0x1d0
[   68.760756]  nfc_unregister_device+0x77/0x190
[   68.760756]  nfcmrvl_nci_unregister_dev+0x88/0xd0
[   68.760756]  nci_uart_tty_close+0xdf/0x180
[   68.760756]  tty_ldisc_kill+0x73/0x110
[   68.760756]  tty_ldisc_hangup+0x281/0x5b0
[   68.760756]  __tty_hangup.part.0+0x431/0x890
[   68.760756]  tty_release+0x3a8/0xc80
[   68.760756]  __fput+0x1f0/0x8c0
[   68.760756]  task_work_run+0xc9/0x170
[   68.760756]  exit_to_user_mode_prepare+0x194/0x1a0
[   68.760756]  syscall_exit_to_user_mode+0x19/0x50
[   68.760756]  do_syscall_64+0x48/0x90
[   68.760756]  entry_SYSCALL_64_after_hwframe+0x44/0xae

This patch just add the null out of dev-&gt;rfkill to make sure such
dereference cannot happen. This is safe since the device_lock() already
protect the check/write from data race.

Fixes: 3e3b5dfcd16a ("NFC: reorder the logic in nfc_{un,}register_device")
Signed-off-by: Lin Ma &lt;linma@zju.edu.cn&gt;
Reviewed-by: Krzysztof Kozlowski &lt;krzysztof.kozlowski@linaro.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: remove noblock parameter from skb_recv_datagram()</title>
<updated>2022-04-06T12:45:26Z</updated>
<author>
<name>Oliver Hartkopp</name>
<email>socketcan@hartkopp.net</email>
</author>
<published>2022-04-04T16:30:22Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/linux-dev/commit/?id=f4b41f062c424209e3939a81e6da022e049a45f2'/>
<id>urn:sha1:f4b41f062c424209e3939a81e6da022e049a45f2</id>
<content type='text'>
skb_recv_datagram() has two parameters 'flags' and 'noblock' that are
merged inside skb_recv_datagram() by 'flags | (noblock ? MSG_DONTWAIT : 0)'

As 'flags' may contain MSG_DONTWAIT as value most callers split the 'flags'
into 'flags' and 'noblock' with finally obsolete bit operations like this:

skb_recv_datagram(sk, flags &amp; ~MSG_DONTWAIT, flags &amp; MSG_DONTWAIT, &amp;rc);

And this is not even done consistently with the 'flags' parameter.

This patch removes the obsolete and costly splitting into two parameters
and only performs bit operations when really needed on the caller side.

One missing conversion thankfully reported by kernel test robot. I missed
to enable kunit tests to build the mctp code.

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
</feed>
