CVE-2025-21791: vrf: use RCU protection in l3mdev_l3_out()

Published Feb 27, 2025
·
Updated

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

vrf: use RCU protection in l3mdevl3out()

l3mdevl3out() can be called without RCU being held:

rawsendmsg() ippushpendingframes() ipsendskb() iplocalout() iplocalout() l3mdevipout()

Add rcureadlock() / rcureadunlock() pair to avoid a potential UAF.

Affected Software

16 affected componentsFixes available
Linux Linux kernel
Linux Linux kernel>=4.9<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 cbl2 kernel 5.15.179.1-1
Microsoft cbl2 kernel 5.15.182.1-1
Microsoft azl3 kernel 6.6.82.1-1
Microsoft cbl2 kernel 5.15.182.1-1
Microsoft azl3 kernel 6.6.78.1-3
IBM Verify Identity Access<=11.0 - 11.0.2
IBM Security Verify Access<=10.0 - 10.0.9.1
IBM Verify Identity Access Container<=11.0 - 11.0.2
IBM Security Verify Access Container<=10.0 - 10.0.9.1

Event History

Feb 27, 2025
CVE Published
via MITRE·02:18 AM
Data Sourced
via MITRE·02:18 AM
Description
Data Sourced
via Red Hat·03:04 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
Updated
via Microsoft·07:00 AM
Description
Jul 8, 2026
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

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Frequently Asked Questions

1

What is the severity of CVE-2025-21791?

CVE-2025-21791 has a severity rating that reflects its potential impact on system stability and security.

2

What systems are affected by CVE-2025-21791?

CVE-2025-21791 affects the Linux kernel, particularly in functions related to routing traffic.

3

How do I fix CVE-2025-21791?

To fix CVE-2025-21791, update the Linux kernel to the latest version that includes the patch.

4

What does CVE-2025-21791 involve?

CVE-2025-21791 involves inadequate protection when calling l3mdev_l3_out() in the Linux kernel.

5

Is there a workaround for CVE-2025-21791?

There is no widely recommended workaround for CVE-2025-21791; updating the kernel is the best approach.

Contact

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