Описание
In the Linux kernel, the following vulnerability has been resolved:
mmc: vub300: defer reset until cmd_mutex is unlocked
vub300_cmndwork_thread() holds cmd_mutex while it sends a command and
waits for the command response. If the response wait times out,
__vub300_command_response() kills the command URBs and then synchronously
resets the USB device through usb_reset_device().
That reset path re-enters the driver through vub300_pre_reset(), which
also takes cmd_mutex. The worker therefore tries to acquire the same
mutex recursively while it is still holding it from the command path.
This issue was found by our static analysis tool and then manually
reviewed against the current tree.
The grounded PoC kept the real worker and timeout/reset carrier:
vub300_cmndwork_thread()
__vub300_command_response()
usb_lock_device_for_reset()
usb_reset_device()
vub300_pre_reset()
Lockdep reported the same-task recursive acquisition on cmd_mutex:
WARNING: possible recursive locking detected
... (&test_vub300.cmd_mutex) ... at: usb_reset_device... [vuln_msv]
... (&test_vub300.cmd_mutex) ... at: vub300_cmndwork_thread+0x12/0x20 [vuln_msv]
Workqueue: vub300_cmd_wq vub300_cmndwork_thread [vuln_msv]
*** DEADLOCK ***
Return a flag from __vub300_command_response() when the timeout path needs
a device reset, then perform the reset after vub300_cmndwork_thread() has
cleared the in-flight command state and dropped cmd_mutex. The reset is
still attempted before mmc_request_done(), preserving the existing request
completion ordering while avoiding the recursive lock.
A flaw was found in the Linux kernel's vub300 driver. When the vub300_cmndwork_thread() function holds a command mutex and a command response times out, the device reset path attempts to re-acquire the same mutex recursively. This recursive locking can lead to a deadlock, causing a Denial of Service (DoS) condition for the system.
Отчет
A low impact flaw was found in the Linux kernel vub300 USB MMC host driver, affecting Red Hat Enterprise Linux 7 through 10 and Red Hat In-Vehicle OS. When a command response times out while vub300_cmndwork_thread() holds cmd_mutex, __vub300_command_response() kills the command URBs and synchronously resets the USB device through usb_reset_device(). That reset path re-enters the driver via vub300_pre_reset(), which attempts to acquire cmd_mutex again while it is still held by the same task, deadlocking the command worker and leaving the MMC request path hung, resulting in a local denial of service. Confidentiality and integrity are not affected and there is no evidence of memory corruption or privilege escalation. Triggering the flaw requires a VUB300 USB MMC device to be present and a command response timeout to occur, so systems without such hardware are not exposed to this code path. Red Hat Enterprise Linux 6 is not affected because the vulnerable code is not present. For the affected streams the fix is currently deferred; the residual risk is limited to a hung kernel workqueue thread causing local denial of service on systems using this specific USB MMC hardware. Although the CVSS:3.1 base score is 5.5 (Moderate), Red Hat rates the impact of this flaw as low because it is not network reachable, requires this specific USB hardware, and only causes local denial of service.
Меры по смягчению последствий
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Fix deferred | ||
| Red Hat Enterprise Linux 8 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel | Fix deferred | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred |
Показывать по
Дополнительная информация
Статус:
5.5 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: mmc: vub300: defer reset until cmd_mutex is unlocked vub300_cmndwork_thread() holds cmd_mutex while it sends a command and waits for the command response. If the response wait times out, __vub300_command_response() kills the command URBs and then synchronously resets the USB device through usb_reset_device(). That reset path re-enters the driver through vub300_pre_reset(), which also takes cmd_mutex. The worker therefore tries to acquire the same mutex recursively while it is still holding it from the command path. This issue was found by our static analysis tool and then manually reviewed against the current tree. The grounded PoC kept the real worker and timeout/reset carrier: vub300_cmndwork_thread() __vub300_command_response() usb_lock_device_for_reset() usb_reset_device() vub300_pre_reset() Lockdep reported the same-task recursive acquisition on cmd_mutex: WARNING: possible recursive locking detected ... (&te...
In the Linux kernel, the following vulnerability has been resolved: mmc: vub300: defer reset until cmd_mutex is unlocked vub300_cmndwork_thread() holds cmd_mutex while it sends a command and waits for the command response. If the response wait times out, __vub300_command_response() kills the command URBs and then synchronously resets the USB device through usb_reset_device(). That reset path re-enters the driver through vub300_pre_reset(), which also takes cmd_mutex. The worker therefore tries to acquire the same mutex recursively while it is still holding it from the command path. This issue was found by our static analysis tool and then manually reviewed against the current tree. The grounded PoC kept the real worker and timeout/reset carrier: vub300_cmndwork_thread() __vub300_command_response() usb_lock_device_for_reset() usb_reset_device() vub300_pre_reset() Lockdep reported the same-task recursive acquisition on cmd_mutex: WARNING: possible recursive locking
In the Linux kernel, the following vulnerability has been resolved: m ...
5.5 Medium
CVSS3