linux-stable/net/nfc/nci
Lin Ma 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
..
core.c NFC: add NCI_UNREG flag to eliminate the race 2021-11-17 20:17:05 -08:00
data.c nfc: nci: constify several pointers to u8, sk_buff and other structs 2021-07-30 17:22:52 +02:00
hci.c nfc: drop unneeded debug prints 2021-10-11 17:00:51 -07:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
lib.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ntf.c nfc: drop unneeded debug prints 2021-10-11 17:00:51 -07:00
rsp.c nfc: nci: fix the UAF of rf_conn_info object 2021-10-08 17:24:32 +01:00
spi.c nfc: nci: constify several pointers to u8, sk_buff and other structs 2021-07-30 17:22:52 +02:00
uart.c TTY / Serial driver update for 5.16-rc1 2021-11-04 09:09:37 -07:00