CVE-2021-47323

watchdog: sc520_wdt: Fix possible use-after-free in wdt_turnoff()

Severity Score

8.8

*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:

watchdog: sc520_wdt: Fix possible use-after-free in wdt_turnoff()

This module's remove path calls del_timer(). However, that function
does not wait until the timer handler finishes. This means that the
timer handler may still be running after the driver's remove function
has finished, which would result in a use-after-free.

Fix by calling del_timer_sync(), which makes sure the timer handler
has finished, and unable to re-schedule itself.

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: watchdog: sc520_wdt: corrige posible use after free en wdt_turnoff(). La ruta de eliminación de este módulo llama a del_timer(). Sin embargo, esa función no espera hasta que finalice el controlador del temporizador. Esto significa que es posible que el controlador del temporizador aún esté ejecutándose después de que haya finalizado la función de eliminación del controlador, lo que daría como resultado un use after free. Para solucionarlo, llame a del_timer_sync(), lo que garantiza que el controlador del temporizador haya finalizado y no pueda reprogramarse.

*Credits: N/A

CVSS Scores

CISAv3.1 8.8

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

* Common Vulnerability Scoring System

SSVC

Decision:Track*

Exploitation

None

Automatable

Tech. Impact

Total

* Organization's Worst-case Scenario

Timeline

2024-05-21 CVE Reserved
2024-05-21 CVE Published
2024-05-22 EPSS Updated
2024-11-04 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-416: Use After Free

CAPEC

References (9)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/0015581a79bbf8e521f85dddb7d3e4a66b9f51d4	2021-07-20
https://git.kernel.org/stable/c/b4565a8a2d6bffb05bfbec11399d261ec16fe373	2021-07-20
https://git.kernel.org/stable/c/2aef07017fae21c3d8acea9656b10e3b9c0f1e04	2021-07-20
https://git.kernel.org/stable/c/522e75ed63f67e815d4ec0deace67df22d9ce78e	2021-07-20
https://git.kernel.org/stable/c/7c56c5508dc20a6b133bc669fc34327a6711c24c	2021-07-20
https://git.kernel.org/stable/c/a173e3b62cf6dd3c4a0a10c8a82eedfcae81a566	2021-07-20
https://git.kernel.org/stable/c/b3c41ea5bc34d8c7b19e230d80e0e555c6f5057d	2021-07-20
https://git.kernel.org/stable/c/f0feab82f6a0323f54d85e8b512a2be64f83648a	2021-07-20
https://git.kernel.org/stable/c/90b7c141132244e8e49a34a4c1e445cce33e07f4	2021-06-21

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"				< 4.4.276 Search vendor "Linux" for product "Linux Kernel" and version " < 4.4.276"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 4.9.276 Search vendor "Linux" for product "Linux Kernel" and version " < 4.9.276"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 4.14.240 Search vendor "Linux" for product "Linux Kernel" and version " < 4.14.240"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 4.19.198 Search vendor "Linux" for product "Linux Kernel" and version " < 4.19.198"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.4.134 Search vendor "Linux" for product "Linux Kernel" and version " < 5.4.134"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.10.52 Search vendor "Linux" for product "Linux Kernel" and version " < 5.10.52"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.12.19 Search vendor "Linux" for product "Linux Kernel" and version " < 5.12.19"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.13.4 Search vendor "Linux" for product "Linux Kernel" and version " < 5.13.4"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				< 5.14 Search vendor "Linux" for product "Linux Kernel" and version " < 5.14"		en		Affected