CVE-2021-46941

usb: dwc3: core: Do core softreset when switch mode

Severity Score

5.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

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

usb: dwc3: core: Do core softreset when switch mode

According to the programming guide, to switch mode for DRD controller,
the driver needs to do the following.

To switch from device to host:
1. Reset controller with GCTL.CoreSoftReset
2. Set GCTL.PrtCapDir(host mode)
3. Reset the host with USBCMD.HCRESET
4. Then follow up with the initializing host registers sequence

To switch from host to device:
1. Reset controller with GCTL.CoreSoftReset
2. Set GCTL.PrtCapDir(device mode)
3. Reset the device with DCTL.CSftRst
4. Then follow up with the initializing registers sequence

Currently we're missing step 1) to do GCTL.CoreSoftReset and step 3) of
switching from host to device. John Stult reported a lockup issue seen
with HiKey960 platform without these steps[1]. Similar issue is observed
with Ferry's testing platform[2].

So, apply the required steps along with some fixes to Yu Chen's and John
Stultz's version. The main fixes to their versions are the missing wait
for clocks synchronization before clearing GCTL.CoreSoftReset and only
apply DCTL.CSftRst when switching from host to device.

[1] https://lore.kernel.org/linux-usb/20210108015115.27920-1-john.stultz@linaro.org/
[2] https://lore.kernel.org/linux-usb/0ba7a6ba-e6a7-9cd4-0695-64fc927e01f1@gmail.com/

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: usb: dwc3: core: Realiza un reinicio suave del núcleo al cambiar de modo Según la guía de programación, para cambiar el modo del controlador DRD, el controlador debe hacer lo siguiente. Para cambiar de dispositivo a host: 1. Reinicie el controlador con GCTL.CoreSoftReset 2. Configure GCTL.PrtCapDir (modo de host) 3. Reinicie el host con USBCMD.HCRESET 4. Luego siga con la secuencia de inicialización de registros del host Para cambiar de host a dispositivo: 1. Reinicie el controlador con GCTL.CoreSoftReset 2. Configure GCTL.PrtCapDir (modo de dispositivo) 3. Reinicie el dispositivo con DCTL.CSftRst 4. Luego siga con la secuencia de inicialización de registros Actualmente nos falta el paso 1) para hacer GCTL .CoreSoftReset y paso 3) de cambio de host a dispositivo. John Stult informó un problema de bloqueo observado con la plataforma HiKey960 sin estos pasos[1]. Se observa un problema similar con la plataforma de pruebas de Ferry[2]. Entonces, aplique los pasos requeridos junto con algunas correcciones a la versión de Yu Chen y John Stultz. Las principales correcciones a sus versiones son la falta de espera para la sincronización de los relojes antes de borrar GCTL.CoreSoftReset y solo aplicar DCTL.CSftRst al cambiar de host a dispositivo. [1] https://lore.kernel.org/linux-usb/20210108015115.27920-1-john.stultz@linaro.org/ [2] https://lore.kernel.org/linux-usb/0ba7a6ba-e6a7- 9cd4-0695-64fc927e01f1@gmail.com/

*Credits: N/A

CVSS Scores

NISTv3.1 5.5

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

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-02-25 CVE Reserved
2024-02-27 CVE Published
2024-04-21 EPSS Updated
2024-08-04 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (5)

URL	Tag	Source
https://git.kernel.org/stable/c/41ce1456e1dbbc7355d0fcc10cf7c337c13def24	Vuln. Introduced

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/fce7bbcd07d59ac30dba8ce225316b3b4c1c7b50	2021-05-11
https://git.kernel.org/stable/c/800f58217626c8b147aa40660e572ed8a0d56e3b	2021-05-12
https://git.kernel.org/stable/c/1c10fd60c8595ea7ff7e29d3cf1fa88069941da3	2021-05-12
https://git.kernel.org/stable/c/f88359e1588b85cf0e8209ab7d6620085f3441d9	2021-04-22

URL	Date	SRC

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"				>= 4.12 < 5.10.36 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.12 < 5.10.36"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.12 < 5.11.20 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.12 < 5.11.20"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.12 < 5.12.3 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.12 < 5.12.3"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.12 < 5.13 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.12 < 5.13"		en		Affected