CVE-2023-52456: serial: imx: fix tx statemachine deadlock
In the Linux kernel, the following vulnerability has been resolved:
serial: imx: fix tx statemachine deadlock
When using the serial port as RS485 port, the tx statemachine is used to control the RTS pin to drive the RS485 transceiver TXEN pin. When the TTY port is closed in the middle of a transmission (for instance during userland application crash), imxuartshutdown disables the interface and disables the Transmission Complete interrupt. afer that, imxuartstoptx bails on an incomplete transmission, to be retriggered by the TC interrupt. This interrupt is disabled and therefore the tx statemachine never transitions out of SEND. The statemachine is in deadlock now, and the TXEN remains low, making the interface useless.
imxuartstoptx now checks for incomplete transmission AND whether TC interrupts are enabled before bailing to be retriggered. This makes sure the state machine handling is reached, and is properly set to WAITAFTERSEND.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2023-52456?
CVE-2023-52456 is classified with a moderate severity due to its impact on the Linux kernel's serial port functionality.
How do I fix CVE-2023-52456?
To fix CVE-2023-52456, update your Linux kernel to version 5.10.223-1, 5.10.226-1, 6.1.119-1, 6.1.123-1, 6.12.10-1, or 6.12.11-1.
Which versions of the Linux kernel are affected by CVE-2023-52456?
CVE-2023-52456 affects Linux kernel versions from 5.9.0 up to 6.7.2, excluding fixed versions.
What is the nature of the vulnerability in CVE-2023-52456?
CVE-2023-52456 involves a deadlock in the tx statemachine of the serial port when used as an RS485 port.
Is CVE-2023-52456 exploitable?
While the specific details of exploitation are not public, the deadlock could potentially disrupt communication flows in affected systems.