CVE-2021-47324: watchdog: Fix possible use-after-free in wdt_startup()

Published May 21, 2024
·
Updated

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

watchdog: Fix possible use-after-free in wdtstartup()

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·04:41 AM
DescriptionSeverityWeakness

Frequently Asked Questions

1

What is the severity of CVE-2021-47324?

CVE-2021-47324 is classified as a high severity vulnerability due to its potential for exploitation in the Linux kernel.

2

How do I fix CVE-2021-47324?

To remediate CVE-2021-47324, users should update their Linux kernel to the latest patched version provided by their distribution.

3

What is the impact of CVE-2021-47324?

CVE-2021-47324 may allow an attacker to exploit a use-after-free condition, potentially leading to arbitrary code execution or system crashes.

4

Which versions of the Linux kernel are affected by CVE-2021-47324?

CVE-2021-47324 affects specific versions of the Linux kernel that incorporate the watchdog timer functionality, particularly prior to the fix.

5

Is CVE-2021-47324 publicly known?

Yes, CVE-2021-47324 is a publicly documented vulnerability that has been reported and acknowledged in the Linux community.

Contact

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