CVE-2021-47323: watchdog: sc520_wdt: Fix possible use-after-free in wdt_turnoff()

Published May 21, 2024
·
Updated

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

watchdog: sc520wdt: Fix possible use-after-free in wdtturnoff()

This module's remove path calls deltimer(). 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 deltimersync(), which makes sure the timer handler has finished, and unable to re-schedule itself.

Affected Software

9 affected components
Linux Kernel
Linux Linux kernel<4.4.276
Linux Linux kernel>=4.5<4.9.276
Linux Linux kernel>=4.10<4.14.240
Linux Linux kernel>=4.15<4.19.198
Linux Linux kernel>=4.20<5.4.134
Linux Linux kernel>=5.5<5.10.52
Linux Linux kernel>=5.11<5.12.19
Linux Linux kernel>=5.13<5.13.4

Event History

May 21, 2024
CVE Published
via MITRE·02:35 PM
Data Sourced
via MITRE·02:35 PM
Description
Sep 4, 2025
Data Sourced
via Microsoft·04:17 AM
DescriptionSeverityWeakness

Frequently Asked Questions

1

What is the severity of CVE-2021-47323?

CVE-2021-47323 has a severity rating of medium due to the potential for a use-after-free vulnerability in the Linux kernel's watchdog module.

2

How do I fix CVE-2021-47323?

To fix CVE-2021-47323, users should update to the latest version of the Linux kernel where the vulnerability has been resolved.

3

What software is affected by CVE-2021-47323?

CVE-2021-47323 affects the Linux kernel, specifically the watchdog: sc520_wdt module.

4

What are the potential impacts of CVE-2021-47323?

If exploited, CVE-2021-47323 could lead to a denial of service or potentially other consequences due to improper handling of timer operations.

5

When was CVE-2021-47323 announced?

CVE-2021-47323 was announced in late 2021 as part of ongoing security updates for the Linux kernel.

Contact

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