// For flags

CVE-2024-26933

USB: core: Fix deadlock in port "disable" sysfs attribute

Severity Score

7.8
*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:

USB: core: Fix deadlock in port "disable" sysfs attribute

The show and store callback routines for the "disable" sysfs attribute
file in port.c acquire the device lock for the port's parent hub
device. This can cause problems if another process has locked the hub
to remove it or change its configuration:

Removing the hub or changing its configuration requires the
hub interface to be removed, which requires the port device
to be removed, and device_del() waits until all outstanding
sysfs attribute callbacks for the ports have returned. The
lock can't be released until then.

But the disable_show() or disable_store() routine can't return
until after it has acquired the lock.

The resulting deadlock can be avoided by calling
sysfs_break_active_protection(). This will cause the sysfs core not
to wait for the attribute's callback routine to return, allowing the
removal to proceed. The disadvantage is that after making this call,
there is no guarantee that the hub structure won't be deallocated at
any moment. To prevent this, we have to acquire a reference to it
first by calling hub_get().

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: USB: core: corrige el punto muerto en el atributo sysfs "disable" del puerto. Las rutinas de devolución de llamada para mostrar y almacenar para el archivo del atributo sysfs "disable" en port.c adquieren el bloqueo del dispositivo para el puerto. dispositivo central principal. Esto puede causar problemas si otro proceso ha bloqueado el concentrador para eliminarlo o cambiar su configuración: Quitar el concentrador o cambiar su configuración requiere que se elimine la interfaz del concentrador, lo que requiere que se elimine el dispositivo del puerto, y device_del() espera hasta que todo Se han devuelto devoluciones de llamadas de atributos sysfs pendientes para los puertos. El bloqueo no podrá desbloquearse hasta entonces. Pero la rutina enable_show() o enable_store() no puede regresar hasta que haya adquirido el bloqueo. El punto muerto resultante se puede evitar llamando a sysfs_break_active_protection(). Esto hará que el núcleo de sysfs no espere a que regrese la rutina de devolución de llamada del atributo, lo que permitirá que continúe la eliminación. La desventaja es que después de realizar esta llamada, no hay garantía de que la estructura del centro no se desasignará en ningún momento. Para evitar esto, primero debemos adquirir una referencia llamando a hub_get().

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
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
  • 2024-02-19 CVE Reserved
  • 2024-05-01 CVE Published
  • 2024-05-24 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"
>= 6.0 < 6.1.84
Search vendor "Linux" for product "Linux Kernel" and version " >= 6.0 < 6.1.84"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 6.0 < 6.6.24
Search vendor "Linux" for product "Linux Kernel" and version " >= 6.0 < 6.6.24"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 6.0 < 6.7.12
Search vendor "Linux" for product "Linux Kernel" and version " >= 6.0 < 6.7.12"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 6.0 < 6.8.3
Search vendor "Linux" for product "Linux Kernel" and version " >= 6.0 < 6.8.3"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 6.0 < 6.9
Search vendor "Linux" for product "Linux Kernel" and version " >= 6.0 < 6.9"
en
Affected