CVE-2025-21764: ndisc: use RCU protection in ndisc_alloc_skb()

Published Feb 27, 2025
·
Updated

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

ndisc: use RCU protection in ndiscallocskb()

ndiscallocskb() can be called without RTNL or RCU being held.

Add RCU protection to avoid possible UAF.

Affected Software

14 affected componentsFixes available
Linux Linux kernel
Linux Linux kernel>=3.9<5.4.291
Linux Linux kernel>=5.5<5.10.235
Linux Linux kernel>=5.11<5.15.179
Linux Linux kernel>=5.16<6.1.129
Linux Linux kernel>=6.2<6.6.79
Linux Linux kernel>=6.7<6.12.16
Linux Linux kernel>=6.13<6.13.4
Linux Linux kernel=6.14-rc1
Linux Linux kernel=6.14-rc2
Microsoft azl3 kernel 6.6.82.1-1<6.6.82.1-1
6.6.82.1-1
Microsoft cbl2 kernel 5.15.176.3-3<5.15.180.1-1
5.15.180.1-1
Microsoft azl3 kernel 6.6.78.1-3<6.6.82.1-1
6.6.82.1-1
Microsoft cbl2 kernel 5.15.180.1-1<5.15.180.1-1
5.15.180.1-1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 6.6.82.1-1
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 5.15.180.1-1

Event History

Feb 27, 2025
CVE Published
via MITRE·02:18 AM
Data Sourced
via MITRE·02:18 AM
DescriptionSeverity
Data Sourced
via Red Hat·03:03 AM
DescriptionSeverityAffected Software
Data Sourced
via NVD·03:15 AM
RemedyDescriptionSeverityWeaknessAffected Software
Apr 9, 2025
Data Sourced
via Microsoft·07:00 AM
DescriptionSeverityWeakness
Data Sourced
via Microsoft·07:00 AM
Affected Software
Updated
via Microsoft·07:00 AM
DescriptionSeverity

Frequently Asked Questions

1

What is the severity of CVE-2025-21764?

CVE-2025-21764 is classified as a medium severity vulnerability in the Linux kernel.

2

How do I fix CVE-2025-21764?

To fix CVE-2025-21764, update to the latest stable version of the Linux kernel that includes the patch.

3

What does CVE-2025-21764 impact?

CVE-2025-21764 impacts the ndisc_alloc_skb() function within the Linux kernel.

4

What type of vulnerability is CVE-2025-21764?

CVE-2025-21764 is a Use After Free (UAF) vulnerability that requires RCU protection in the kernel.

5

Is CVE-2025-21764 exploitable in all versions of the Linux kernel?

CVE-2025-21764 is exploitable in certain versions of the Linux kernel, specifically those prior to the patch.

Contact

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