Описание
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: u_serial: Fix race condition in TTY wakeup A race condition occurs when gs_start_io() calls either gs_start_rx() or gs_start_tx(), as those functions briefly drop the port_lock for usb_ep_queue(). This allows gs_close() and gserial_disconnect() to clear port.tty and port_usb, respectively. Use the null-safe TTY Port helper function to wake up TTY. Example CPU1: CPU2: gserial_connect() // lock gs_close() // await lock gs_start_rx() // unlock usb_ep_queue() gs_close() // lock, reset port.tty and unlock gs_start_rx() // lock tty_wakeup() // NPE
Отчет
This patch fixes a race condition in the u_serial USB gadget driver, where a NULL pointer dereference could occur if the TTY port is closed or disconnected while gs_start_io() is still in progress. The bug results from a temporary unlock of port_lock, allowing another thread to reset port->tty before tty_wakeup() is called. The patch replaces the direct TTY access with a null-safe helper, tty_port_tty_wakeup(). Although the race is timing-sensitive, it is user-triggerable and may lead to a kernel crash, making it a potential local denial-of-service issue. Related u_serial Kernel module disabled for all versions of Red Hat Enterprise Linux, and as result not affected.
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 | Not affected | ||
Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
Red Hat Enterprise Linux 8 | kernel | Not affected | ||
Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
Red Hat Enterprise Linux 9 | kernel | Not affected | ||
Red Hat Enterprise Linux 9 | kernel-rt | Not affected |
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Дополнительная информация
Статус:
EPSS
6.2 Medium
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: u_serial: Fix race condition in TTY wakeup A race condition occurs when gs_start_io() calls either gs_start_rx() or gs_start_tx(), as those functions briefly drop the port_lock for usb_ep_queue(). This allows gs_close() and gserial_disconnect() to clear port.tty and port_usb, respectively. Use the null-safe TTY Port helper function to wake up TTY. Example CPU1: CPU2: gserial_connect() // lock gs_close() // await lock gs_start_rx() // unlock usb_ep_queue() gs_close() // lock, reset port.tty and unlock gs_start_rx() // lock tty_wakeup() // NPE
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: u_serial: Fix race condition in TTY wakeup A race condition occurs when gs_start_io() calls either gs_start_rx() or gs_start_tx(), as those functions briefly drop the port_lock for usb_ep_queue(). This allows gs_close() and gserial_disconnect() to clear port.tty and port_usb, respectively. Use the null-safe TTY Port helper function to wake up TTY. Example CPU1: CPU2: gserial_connect() // lock gs_close() // await lock gs_start_rx() // unlock usb_ep_queue() gs_close() // lock, reset port.tty and unlock gs_start_rx() // lock tty_wakeup() // NPE
In the Linux kernel, the following vulnerability has been resolved: u ...
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: u_serial: Fix race condition in TTY wakeup A race condition occurs when gs_start_io() calls either gs_start_rx() or gs_start_tx(), as those functions briefly drop the port_lock for usb_ep_queue(). This allows gs_close() and gserial_disconnect() to clear port.tty and port_usb, respectively. Use the null-safe TTY Port helper function to wake up TTY. Example CPU1: CPU2: gserial_connect() // lock gs_close() // await lock gs_start_rx() // unlock usb_ep_queue() gs_close() // lock, reset port.tty and unlock gs_start_rx() // lock tty_wakeup() // NPE
Уязвимость функции gs_start_io() компонента usb ядра операционной системы Linux, позволяющая нарушителю вызвать отказ в обслуживании
EPSS
6.2 Medium
CVSS3