linux-stable.git/net/nfc, branch v5.18.3

NFC: NULL out the dev->rfkill to prevent UAF

2022-06-09T08:29:58+00:00

[ Upstream commit 1b0e81416a24d6e9b8c2341e22e8bf48f8b8bfc9 ]

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(&dev->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]  
[   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]  
[   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->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 
Reviewed-by: Krzysztof Kozlowski 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

NFC: nci: fix sleep in atomic context bugs caused by nci_skb_alloc

2022-05-18T00:55:53+00:00

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 
Reviewed-by: Krzysztof Kozlowski 
Link: https://lore.kernel.org/r/20220517012530.75714-1-duoming@zju.edu.cn
Signed-off-by: Jakub Kicinski

NFC: netlink: fix sleep in atomic bug when firmware download timeout

2022-05-05T08:18:15+00:00

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 
Reviewed-by: Krzysztof Kozlowski 
Link: https://lore.kernel.org/r/20220504055847.38026-1-duoming@zju.edu.cn
Signed-off-by: Paolo Abeni

nfc: replace improper check device_is_registered() in netlink related functions

2022-05-01T12:26:05+00:00

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 
Signed-off-by: David S. Miller

nfc: nci: add flush_workqueue to prevent uaf

2022-04-13T13:44:44+00:00

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]  
[   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]  
[   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 
Reviewed-by: Krzysztof Kozlowski 
Signed-off-by: David S. Miller

nfc: llcp: Revert "NFC: Keep socket alive until the DISC PDU is actually sent"

2022-03-03T10:43:37+00:00

This reverts commit 17f7ae16aef1f58bc4af4c7a16b8778a91a30255.

The commit brought a new socket state LLCP_DISCONNECTING, which was
never set, only read, so socket could never set to such state.

Remove the dead code.

Signed-off-by: Krzysztof Kozlowski 
Signed-off-by: David S. Miller

nfc: llcp: protect nfc_llcp_sock_unlink() calls

2022-03-03T10:43:37+00:00

nfc_llcp_sock_link() is called in all paths (bind/connect) as a last
action, still protected with lock_sock().  When cleaning up in
llcp_sock_release(), call nfc_llcp_sock_unlink() in a mirrored way:
earlier and still under the lock_sock().

Signed-off-by: Krzysztof Kozlowski 
Signed-off-by: David S. Miller

nfc: llcp: use test_bit()

2022-03-03T10:43:37+00:00

Use test_bit() instead of open-coding it, just like in other places
touching the bitmap.

Signed-off-by: Krzysztof Kozlowski 
Signed-off-by: David S. Miller

nfc: llcp: use centralized exiting of bind on errors

2022-03-03T10:43:37+00:00

Coding style encourages centralized exiting of functions, so rewrite
llcp_sock_bind() error paths to use such pattern.  This reduces the
duplicated cleanup code, make success path visually shorter and also
cleans up the errors in proper order (in reversed way from
initialization).

No functional impact expected.

Signed-off-by: Krzysztof Kozlowski 
Signed-off-by: David S. Miller

nfc: llcp: simplify llcp_sock_connect() error paths

2022-03-03T10:43:37+00:00

The llcp_sock_connect() error paths were using a mixed way of central
exit (goto) and cleanup

Signed-off-by: Krzysztof Kozlowski 
Signed-off-by: David S. Miller