CVE-2023-53168

In the Linux kernel, the following vulnerability has been resolved:

usb: ucsi_acpi: Increase the command completion timeout

Commit 130a96d698d7 (usb: typec: ucsi: acpi: Increase command completion timeout value) increased the timeout from 5 seconds to 60 seconds due to issues related to alternate mode discovery.

After the alternate mode discovery switch to polled mode the timeout was reduced, but instead of being set back to 5 seconds it was reduced to 1 second.

This is causing problems when using a Lenovo ThinkPad X1 yoga gen7 connected over Type-C to a LG 27UL850-W (charging DP over Type-C).

When the monitor is already connected at boot the following error is logged: PPM init failed (-110), /sys/class/typec is empty and on unplugging the NULL pointer deref fixed earlier in this series happens.

When the monitor is connected after boot the following error is logged instead: GET_CONNECTOR_STATUS failed (-110).

Setting the timeout back to 5 seconds fixes both cases.

Weakness

The product dereferences a pointer that it expects to be valid but is NULL.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/02d210f434249a7edbc160969b75df030dc6934d
• https://git.kernel.org/stable/c/1e8525f37871741a52370627633962f8bdcab15a
• https://git.kernel.org/stable/c/8346d21d1d8a63f46f60e6899f4f80b1306acf32