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
..
digital.h	nfc: constify nfc_digital_ops	2021-07-25 09:21:21 +01:00
hci.h	nfc: constify nfc_hci_ops	2021-07-25 09:21:21 +01:00
llc.h	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 399	2019-06-05 17:37:12 +02:00
nci.h	net/nfc/nci: Support NCI 2.x initial sequence	2020-12-04 17:47:35 -08:00
nci_core.h	NFC: add NCI_UNREG flag to eliminate the race	2021-11-17 20:17:05 -08:00
nfc.h	nfc: constify several pointers to u8, char and sk_buff	2021-07-30 17:22:52 +02:00