// For flags

CVE-2023-52456

serial: imx: fix tx statemachine deadlock

Severity Score

5.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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 TX_EN pin. When the
TTY port is closed in the middle of a transmission (for instance during
userland application crash), imx_uart_shutdown disables the interface
and disables the Transmission Complete interrupt. afer that,
imx_uart_stop_tx 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 TX_EN remains low, making the interface useless.

imx_uart_stop_tx 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
WAIT_AFTER_SEND.

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: serial: imx: corrige el punto muerto de la máquina de estado tx Cuando se usa el puerto serie como puerto RS485, la máquina de estado tx se usa para controlar el pin RTS para controlar el pin TX_EN del transceptor RS485. Cuando el puerto TTY se cierra en medio de una transmisión (por ejemplo, durante una falla de la aplicación en el área de usuario), imx_uart_shutdown deshabilita la interfaz y deshabilita la interrupción de transmisión completa. Después de eso, imx_uart_stop_tx abandona una transmisión incompleta, para ser reactivada por la interrupción de TC. Esta interrupción está deshabilitada y, por lo tanto, la máquina de estados tx nunca sale de ENVIAR. La máquina de estados ahora está en punto muerto y TX_EN permanece bajo, lo que hace que la interfaz sea inútil. imx_uart_stop_tx ahora verifica si hay transmisiones incompletas Y si las interrupciones TC están habilitadas antes de volver a activar el rescate. Esto garantiza que se alcance el estado de manejo de la máquina y que esté configurado correctamente en WAIT_AFTER_SEND.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-02-20 CVE Reserved
  • 2024-02-23 CVE Published
  • 2024-05-01 EPSS Updated
  • 2024-12-19 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-667: Improper Locking
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.9 < 5.10.209
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.9 < 5.10.209"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.9 < 5.15.148
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.9 < 5.15.148"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.9 < 6.1.75
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.9 < 6.1.75"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.9 < 6.6.14
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.9 < 6.6.14"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.9 < 6.7.2
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.9 < 6.7.2"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.9 < 6.8
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.9 < 6.8"
en
Affected