[ 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] <TASK>
[ 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] </TASK>
[ 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 <linma@zju.edu.cn>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 23dd4581350d4ffa23d58976ec46408f8f4c1e16 ]
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 <duoming@zju.edu.cn>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220517012530.75714-1-duoming@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 4071bf121d59944d5cd2238de0642f3d7995a997 upstream.
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 <duoming@zju.edu.cn>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220504055847.38026-1-duoming@zju.edu.cn
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit da5c0f119203ad9728920456a0f52a6d850c01cd upstream.
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 <duoming@zju.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit ef27324e2cb7bb24542d6cb2571740eefe6b00dc ]
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] <TASK>
[ 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] </TASK>
[ 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 <linma@zju.edu.cn>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit dded08927ca3c31a5c37f8e7f95fe98770475dd4 upstream.
Syzbot detected a NULL pointer dereference of nfc_llcp_sock->dev pointer
(which is a 'struct nfc_dev *') with calls to llcp_sock_sendmsg() after
a failed llcp_sock_bind(). The message being sent is a SOCK_DGRAM.
KASAN report:
BUG: KASAN: null-ptr-deref in nfc_alloc_send_skb+0x2d/0xc0
Read of size 4 at addr 00000000000005c8 by task llcp_sock_nfc_a/899
CPU: 5 PID: 899 Comm: llcp_sock_nfc_a Not tainted 5.16.0-rc6-next-20211224-00001-gc6437fbf18b0 #125
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x45/0x59
? nfc_alloc_send_skb+0x2d/0xc0
__kasan_report.cold+0x117/0x11c
? mark_lock+0x480/0x4f0
? nfc_alloc_send_skb+0x2d/0xc0
kasan_report+0x38/0x50
nfc_alloc_send_skb+0x2d/0xc0
nfc_llcp_send_ui_frame+0x18c/0x2a0
? nfc_llcp_send_i_frame+0x230/0x230
? __local_bh_enable_ip+0x86/0xe0
? llcp_sock_connect+0x470/0x470
? llcp_sock_connect+0x470/0x470
sock_sendmsg+0x8e/0xa0
____sys_sendmsg+0x253/0x3f0
...
The issue was visible only with multiple simultaneous calls to bind() and
sendmsg(), which resulted in most of the bind() calls to fail. The
bind() was failing on checking if there is available WKS/SDP/SAP
(respective bit in 'struct nfc_llcp_local' fields). When there was no
available WKS/SDP/SAP, the bind returned error but the sendmsg() to such
socket was able to trigger mentioned NULL pointer dereference of
nfc_llcp_sock->dev.
The code looks simply racy and currently it protects several paths
against race with checks for (!nfc_llcp_sock->local) which is NULL-ified
in error paths of bind(). The llcp_sock_sendmsg() did not have such
check but called function nfc_llcp_send_ui_frame() had, although not
protected with lock_sock().
Therefore the race could look like (same socket is used all the time):
CPU0 CPU1
==== ====
llcp_sock_bind()
- lock_sock()
- success
- release_sock()
- return 0
llcp_sock_sendmsg()
- lock_sock()
- release_sock()
llcp_sock_bind(), same socket
- lock_sock()
- error
- nfc_llcp_send_ui_frame()
- if (!llcp_sock->local)
- llcp_sock->local = NULL
- nfc_put_device(dev)
- dereference llcp_sock->dev
- release_sock()
- return -ERRNO
The nfc_llcp_send_ui_frame() checked llcp_sock->local outside of the
lock, which is racy and ineffective check. Instead, its caller
llcp_sock_sendmsg(), should perform the check inside lock_sock().
Reported-and-tested-by: syzbot+7f23bcddf626e0593a39@syzkaller.appspotmail.com
Fixes: b874dec21d1c ("NFC: Implement LLCP connection less Tx path")
Cc: <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fd79a0cbf0b2e34bcc45b13acf962e2032a82203 upstream. When kmalloc in nfc_genl_dump_devices() fails then nfc_genl_dump_devices_done() segfaults as below KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 PID: 25 Comm: kworker/0:1 Not tainted 5.16.0-rc4-01180-g2a987e65025e-dirty #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-6.fc35 04/01/2014 Workqueue: events netlink_sock_destruct_work RIP: 0010:klist_iter_exit+0x26/0x80 Call Trace: <TASK> class_dev_iter_exit+0x15/0x20 nfc_genl_dump_devices_done+0x3b/0x50 genl_lock_done+0x84/0xd0 netlink_sock_destruct+0x8f/0x270 __sk_destruct+0x64/0x3b0 sk_destruct+0xa8/0xd0 __sk_free+0x2e8/0x3d0 sk_free+0x51/0x90 netlink_sock_destruct_work+0x1c/0x20 process_one_work+0x411/0x710 worker_thread+0x6fd/0xa80 Link: https://syzkaller.appspot.com/bug?id=fc0fa5a53db9edd261d56e74325419faf18bd0df Reported-by: syzbot+f9f76f4a0766420b4a02@syzkaller.appspotmail.com Signed-off-by: Tadeusz Struk <tadeusz.struk@linaro.org> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com> Link: https://lore.kernel.org/r/20211208182742.340542-1-tadeusz.struk@linaro.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4cd8371a234d051f9c9557fcbb1f8c523b1c0d10 upstream.
The done() netlink callback nfc_genl_dump_ses_done() should check if
received argument is non-NULL, because its allocation could fail earlier
in dumpit() (nfc_genl_dump_ses()).
Fixes: ac22ac466a65 ("NFC: Add a GET_SE netlink API")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211209081307.57337-1-krzysztof.kozlowski@canonical.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 48b71a9e66c2eab60564b1b1c85f4928ed04e406 upstream.
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: 6a2968aaf50c ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3e3b5dfcd16a3e254aab61bd1e8c417dd4503102 ]
There is a potential UAF between the unregistration routine and the NFC
netlink operations.
The race that cause that UAF can be shown as below:
(FREE) | (USE)
nfcmrvl_nci_unregister_dev | nfc_genl_dev_up
nci_close_device |
nci_unregister_device | nfc_get_device
nfc_unregister_device | nfc_dev_up
rfkill_destory |
device_del | rfkill_blocked
... | ...
The root cause for this race is concluded below:
1. The rfkill_blocked (USE) in nfc_dev_up is supposed to be placed after
the device_is_registered check.
2. Since the netlink operations are possible just after the device_add
in nfc_register_device, the nfc_dev_up() can happen anywhere during the
rfkill creation process, which leads to data race.
This patch reorder these actions to permit
1. Once device_del is finished, the nfc_dev_up cannot dereference the
rfkill object.
2. The rfkill_register need to be placed after the device_add of nfc_dev
because the parent device need to be created first. So this patch keeps
the order but inject device_lock to prevent the data race.
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Fixes: be055b2f89b5 ("NFC: RFKILL support")
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211116152652.19217-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>