CVE-2025-21920

Source
https://nvd.nist.gov/vuln/detail/CVE-2025-21920
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-21920.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2025-21920
Related
Published
2025-04-01T16:15:22Z
Modified
2025-04-12T15:40:28.871217Z
Severity
  • 7.1 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H CVSS Calculator
Summary
[none]
Details

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

vlan: enforce underlying device type

Currently, VLAN devices can be created on top of non-ethernet devices.

Besides the fact that it doesn't make much sense, this also causes a bug which leaks the address of a kernel function to usermode.

When creating a VLAN device, we initialize GARP (garpinitapplicant) and MRP (mrpinitapplicant) for the underlying device.

As part of the initialization process, we add the multicast address of each applicant to the underlying device, by calling devmcadd.

_devmcadd uses dev->addrlen to determine the length of the new multicast address.

This causes an out-of-bounds read if dev->addr_len is greater than 6, since the multicast addresses provided by GARP and MRP are only 6 bytes long.

This behaviour can be reproduced using the following commands:

ip tunnel add gretest mode ip6gre local ::1 remote ::2 dev lo ip l set up dev gretest ip link add link gretest name vlantest type vlan id 100

Then, the following command will display the address of garppdurcv:

ip maddr show | grep 01:80:c2:00:00:21

Fix the bug by enforcing the type of the underlying device during VLAN device initialization.

References

Affected packages

Debian:11 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

5.*

5.10.46-4
5.10.46-5
5.10.70-1~bpo10+1
5.10.70-1
5.10.84-1
5.10.92-1~bpo10+1
5.10.92-1
5.10.92-2
5.10.103-1~bpo10+1
5.10.103-1
5.10.106-1
5.10.113-1
5.10.120-1~bpo10+1
5.10.120-1
5.10.127-1
5.10.127-2~bpo10+1
5.10.127-2
5.10.136-1
5.10.140-1
5.10.148-1
5.10.149-1
5.10.149-2
5.10.158-1
5.10.158-2
5.10.162-1
5.10.178-1
5.10.178-2
5.10.178-3
5.10.179-1
5.10.179-2
5.10.179-3
5.10.179-4
5.10.179-5
5.10.191-1
5.10.197-1
5.10.205-1
5.10.205-2
5.10.209-1
5.10.209-2
5.10.216-1
5.10.218-1
5.10.221-1
5.10.223-1
5.10.226-1
5.10.234-1
5.13.9-1~exp1
5.13.9-1~exp2
5.13.12-1~exp1
5.14-1~exp1
5.14-1~exp2
5.14.1-1~exp1
5.14.2-1~exp1
5.14.3-1~exp1
5.14.6-1
5.14.6-2
5.14.6-3
5.14.9-1
5.14.9-2~bpo11+1
5.14.9-2
5.14.12-1
5.14.16-1
5.15-1~exp1
5.15.1-1~exp1
5.15.2-1~exp1
5.15.3-1
5.15.5-1
5.15.5-2~bpo11+1
5.15.5-2
5.15.15-1
5.15.15-2~bpo11+1
5.15.15-2
5.16~rc1-1~exp1
5.16~rc3-1~exp1
5.16~rc4-1~exp1
5.16~rc5-1~exp1
5.16~rc6-1~exp1
5.16~rc7-1~exp1
5.16~rc8-1~exp1
5.16.3-1~exp1
5.16.4-1~exp1
5.16.7-1
5.16.7-2
5.16.10-1
5.16.11-1~bpo11+1
5.16.11-1
5.16.12-1~bpo11+1
5.16.12-1
5.16.14-1
5.16.18-1
5.17~rc3-1~exp1
5.17~rc4-1~exp1
5.17~rc5-1~exp1
5.17~rc6-1~exp1
5.17~rc7-1~exp1
5.17~rc8-1~exp1
5.17.1-1~exp1
5.17.3-1
5.17.6-1
5.17.11-1
5.18-1~exp1
5.18.2-1~bpo11+1
5.18.2-1
5.18.5-1
5.18.14-1~bpo11+1
5.18.14-1
5.18.16-1~bpo11+1
5.18.16-1
5.19~rc4-1~exp1
5.19~rc6-1~exp1
5.19-1~exp1
5.19.6-1
5.19.11-1~bpo11+1
5.19.11-1

6.*

6.0~rc7-1~exp1
6.0-1~exp1
6.0.2-1
6.0.3-1~bpo11+1
6.0.3-1
6.0.5-1
6.0.6-1
6.0.6-2
6.0.7-1
6.0.8-1
6.0.10-1
6.0.10-2
6.0.12-1~bpo11+1
6.0.12-1
6.0.12-1+alpha
6.1~rc3-1~exp1
6.1~rc5-1~exp1
6.1~rc6-1~exp1
6.1~rc7-1~exp1
6.1~rc8-1~exp1
6.1.1-1~exp1
6.1.1-1~exp2
6.1.2-1~exp1
6.1.4-1
6.1.7-1
6.1.8-1
6.1.8-1+sh4
6.1.11-1
6.1.12-1~bpo11+1
6.1.12-1
6.1.15-1~bpo11+1
6.1.15-1
6.1.20-1~bpo11+1
6.1.20-1
6.1.20-2~bpo11+1
6.1.20-2
6.1.25-1
6.1.27-1~bpo11+1
6.1.27-1
6.1.37-1
6.1.38-1
6.1.38-2~bpo11+1
6.1.38-2
6.1.38-3
6.1.38-4~bpo11+1
6.1.38-4
6.1.52-1
6.1.55-1~bpo11+1
6.1.55-1
6.1.64-1
6.1.66-1
6.1.67-1
6.1.69-1~bpo11+1
6.1.69-1
6.1.76-1~bpo11+1
6.1.76-1
6.1.82-1
6.1.85-1
6.1.90-1~bpo11+1
6.1.90-1
6.1.94-1~bpo11+1
6.1.94-1
6.1.98-1
6.1.99-1
6.1.106-1
6.1.106-2
6.1.106-3
6.1.112-1
6.1.115-1
6.1.119-1
6.1.123-1
6.1.124-1
6.1.128-1
6.1.129-1
6.1.133-1
6.3.1-1~exp1
6.3.2-1~exp1
6.3.4-1~exp1
6.3.5-1~exp1
6.3.7-1~bpo12+1
6.3.7-1
6.3.11-1
6.4~rc6-1~exp1
6.4~rc7-1~exp1
6.4.1-1~exp1
6.4.4-1~bpo12+1
6.4.4-1
6.4.4-2
6.4.4-3~bpo12+1
6.4.4-3
6.4.11-1
6.4.13-1
6.5~rc4-1~exp1
6.5~rc6-1~exp1
6.5~rc7-1~exp1
6.5.1-1~exp1
6.5.3-1~bpo12+1
6.5.3-1
6.5.6-1
6.5.8-1
6.5.10-1~bpo12+1
6.5.10-1
6.5.13-1
6.6.3-1~exp1
6.6.4-1~exp1
6.6.7-1~exp1
6.6.8-1
6.6.9-1
6.6.11-1
6.6.13-1~bpo12+1
6.6.13-1
6.6.15-1
6.6.15-2
6.7-1~exp1
6.7.1-1~exp1
6.7.4-1~exp1
6.7.7-1
6.7.9-1
6.7.9-2
6.7.12-1~bpo12+1
6.7.12-1
6.8.9-1
6.8.11-1
6.8.12-1~bpo12+1
6.8.12-1
6.9.2-1~exp1
6.9.7-1~bpo12+1
6.9.7-1
6.9.8-1
6.9.9-1
6.9.10-1~bpo12+1
6.9.10-1
6.9.11-1
6.9.12-1
6.10-1~exp1
6.10.1-1~exp1
6.10.3-1
6.10.4-1
6.10.6-1~bpo12+1
6.10.6-1
6.10.7-1
6.10.9-1
6.10.11-1~bpo12+1
6.10.11-1
6.10.12-1
6.11~rc4-1~exp1
6.11~rc5-1~exp1
6.11-1~exp1
6.11.2-1
6.11.4-1
6.11.5-1~bpo12+1
6.11.5-1
6.11.6-1
6.11.7-1
6.11.9-1
6.11.10-1~bpo12+1
6.11.10-1
6.12~rc6-1~exp1
6.12.3-1
6.12.5-1
6.12.6-1
6.12.8-1
6.12.9-1~bpo12+1
6.12.9-1
6.12.9-1+alpha
6.12.10-1
6.12.11-1
6.12.11-1+alpha
6.12.11-1+alpha.1
6.12.12-1~bpo12+1
6.12.12-1
6.12.13-1
6.12.15-1
6.12.16-1
6.12.17-1
6.12.19-1
6.12.20-1
6.12.21-1
6.12.22-1
6.13~rc6-1~exp1
6.13~rc7-1~exp1
6.13.2-1~exp1
6.13.3-1~exp1
6.13.4-1~exp1
6.13.5-1~exp1
6.13.6-1~exp1
6.13.7-1~exp1
6.13.8-1~exp1
6.13.9-1~exp1
6.13.10-1~exp1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:12 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
6.1.133-1

Affected versions

6.*

6.1.27-1
6.1.37-1
6.1.38-1
6.1.38-2~bpo11+1
6.1.38-2
6.1.38-3
6.1.38-4~bpo11+1
6.1.38-4
6.1.52-1
6.1.55-1~bpo11+1
6.1.55-1
6.1.64-1
6.1.66-1
6.1.67-1
6.1.69-1~bpo11+1
6.1.69-1
6.1.76-1~bpo11+1
6.1.76-1
6.1.82-1
6.1.85-1
6.1.90-1~bpo11+1
6.1.90-1
6.1.94-1~bpo11+1
6.1.94-1
6.1.98-1
6.1.99-1
6.1.106-1
6.1.106-2
6.1.106-3
6.1.112-1
6.1.115-1
6.1.119-1
6.1.123-1
6.1.124-1
6.1.128-1
6.1.129-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Debian:13 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
6.12.19-1

Affected versions

6.*

6.1.27-1
6.1.37-1
6.1.38-1
6.1.38-2~bpo11+1
6.1.38-2
6.1.38-3
6.1.38-4~bpo11+1
6.1.38-4
6.1.52-1
6.1.55-1~bpo11+1
6.1.55-1
6.1.64-1
6.1.66-1
6.1.67-1
6.1.69-1~bpo11+1
6.1.69-1
6.1.76-1~bpo11+1
6.1.76-1
6.1.82-1
6.1.85-1
6.1.90-1~bpo11+1
6.1.90-1
6.1.94-1~bpo11+1
6.1.94-1
6.1.98-1
6.1.99-1
6.1.106-1
6.1.106-2
6.1.106-3
6.1.112-1
6.1.115-1
6.1.119-1
6.1.123-1
6.1.124-1
6.1.128-1
6.1.129-1
6.1.133-1
6.3.1-1~exp1
6.3.2-1~exp1
6.3.4-1~exp1
6.3.5-1~exp1
6.3.7-1~bpo12+1
6.3.7-1
6.3.11-1
6.4~rc6-1~exp1
6.4~rc7-1~exp1
6.4.1-1~exp1
6.4.4-1~bpo12+1
6.4.4-1
6.4.4-2
6.4.4-3~bpo12+1
6.4.4-3
6.4.11-1
6.4.13-1
6.5~rc4-1~exp1
6.5~rc6-1~exp1
6.5~rc7-1~exp1
6.5.1-1~exp1
6.5.3-1~bpo12+1
6.5.3-1
6.5.6-1
6.5.8-1
6.5.10-1~bpo12+1
6.5.10-1
6.5.13-1
6.6.3-1~exp1
6.6.4-1~exp1
6.6.7-1~exp1
6.6.8-1
6.6.9-1
6.6.11-1
6.6.13-1~bpo12+1
6.6.13-1
6.6.15-1
6.6.15-2
6.7-1~exp1
6.7.1-1~exp1
6.7.4-1~exp1
6.7.7-1
6.7.9-1
6.7.9-2
6.7.12-1~bpo12+1
6.7.12-1
6.8.9-1
6.8.11-1
6.8.12-1~bpo12+1
6.8.12-1
6.9.2-1~exp1
6.9.7-1~bpo12+1
6.9.7-1
6.9.8-1
6.9.9-1
6.9.10-1~bpo12+1
6.9.10-1
6.9.11-1
6.9.12-1
6.10-1~exp1
6.10.1-1~exp1
6.10.3-1
6.10.4-1
6.10.6-1~bpo12+1
6.10.6-1
6.10.7-1
6.10.9-1
6.10.11-1~bpo12+1
6.10.11-1
6.10.12-1
6.11~rc4-1~exp1
6.11~rc5-1~exp1
6.11-1~exp1
6.11.2-1
6.11.4-1
6.11.5-1~bpo12+1
6.11.5-1
6.11.6-1
6.11.7-1
6.11.9-1
6.11.10-1~bpo12+1
6.11.10-1
6.12~rc6-1~exp1
6.12.3-1
6.12.5-1
6.12.6-1
6.12.8-1
6.12.9-1~bpo12+1
6.12.9-1
6.12.9-1+alpha
6.12.10-1
6.12.11-1
6.12.11-1+alpha
6.12.11-1+alpha.1
6.12.12-1~bpo12+1
6.12.12-1
6.12.13-1
6.12.15-1
6.12.16-1
6.12.17-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}