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
| Software | From | Fixed in |
|---|---|---|
| linux / linux_kernel | 3.5 | 5.4.296 |
| linux / linux_kernel | 5.5 | 5.10.240 |
| linux / linux_kernel | 5.11 | 5.15.189 |
| linux / linux_kernel | 5.16 | 6.1.146 |
| linux / linux_kernel | 6.2 | 6.6.99 |
| linux / linux_kernel | 6.7 | 6.12.39 |
| linux / linux_kernel | 6.13 | 6.15.7 |
| linux / linux_kernel | 6.16-rc1 | 6.16-rc1.x |
| linux / linux_kernel | 6.16-rc2 | 6.16-rc2.x |
| linux / linux_kernel | 6.16-rc3 | 6.16-rc3.x |
| linux / linux_kernel | 6.16-rc4 | 6.16-rc4.x |
| debian / debian_linux | 11.0 | 11.0.x |