net: vlan: fix VLAN 0 refcount imbalance of toggling filtering during runtime
In the Linux kernel, the following vulnerability has been resolved: net: vlan: fix VLAN 0 refcount imbalance of toggling filtering during runtime Assuming the "rx-vlan-filter" feature is enabled on a net device, the 8021q module will automatically add or remove VLAN 0 when the net device is put administratively up or down, respectively. There are a couple of problems with the above scheme. The first problem is a memory leak that can happen if the "rx-vlan-filter" feature is disabled while the device is running: # ip link add bond1 up type bond mode 0 # ethtool -K bond1 rx-vlan-filter off # ip link del dev bond1 When the device is put administratively down the "rx-vlan-filter" feature is disabled, so the 8021q module will not remove VLAN 0 and the memory will be leaked [1]. Another problem that can happen is that the kernel can automatically delete VLAN 0 when the device is put administratively down despite not adding it when the device was put administratively up since during that time the "rx-vlan-filter" feature was disabled. null-ptr-unref or bug_on[2] will be triggered by unregister_vlan_dev() for refcount imbalance if toggling filtering during runtime: $ ip link add bond0 type bond mode 0 $ ip link add link bond0 name vlan0 type vlan id 0 protocol 802.1q $ ethtool -K bond0 rx-vlan-filter off $ ifconfig bond0 up $ ethtool -K bond0 rx-vlan-filter on $ ifconfig bond0 down $ ip link del vlan0 Root cause is as below: step1: add vlan0 for real_dev, such as bond, team. register
CVE-2025-38470
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2025-38470
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "ad1afb00393915a51c21b1ae8704562bf036855f",
"lessThan": "ba48d3993af23753e1f1f01c8d592de9c7785f24",
"versionType": "git"
},
{
"status": "affected",
"version": "ad1afb00393915a51c21b1ae8704562bf036855f",
"lessThan": "35142b3816832889e50164d993018ea5810955ae",
"versionType": "git"
},
{
"status": "affected",
"version": "ad1afb00393915a51c21b1ae8704562bf036855f",
"lessThan": "047b61a24d7c866c502aeeea482892969a68f216",
"versionType": "git"
},
{
"status": "affected",
"version": "ad1afb00393915a51c21b1ae8704562bf036855f",
"lessThan": "d43ef15bf4856c8c4c6c3572922331a5f06deb77",
"versionType": "git"
},
{
"status": "affected",
"version": "ad1afb00393915a51c21b1ae8704562bf036855f",
"lessThan": "bb515c41306454937464da055609b5fb0a27821b",
"versionType": "git"
},
{
"status": "affected",
"version": "ad1afb00393915a51c21b1ae8704562bf036855f",
"lessThan": "8984bcbd1edf5bee5be06ad771d157333b790c33",
"versionType": "git"
},
{
"status": "affected",
"version": "ad1afb00393915a51c21b1ae8704562bf036855f",
"lessThan": "93715aa2d80e6c5cea1bb486321fc4585076928b",
"versionType": "git"
},
{
"status": "affected",
"version": "ad1afb00393915a51c21b1ae8704562bf036855f",
"lessThan": "579d4f9ca9a9a605184a9b162355f6ba131f678d",
"versionType": "git"
}
],
"programFiles": [
"net/8021q/vlan.c",
"net/8021q/vlan.h"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "2.6.36"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "2.6.36",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.4.297",
"versionType": "semver",
"lessThanOrEqual": "5.4.*"
},
{
"status": "unaffected",
"version": "5.10.241",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.190",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.147",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.100",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.40",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.15.8",
"versionType": "semver",
"lessThanOrEqual": "6.15.*"
},
{
"status": "unaffected",
"version": "6.16",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/8021q/vlan.c",
"net/8021q/vlan.h"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2025-38470
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #30576 · Revision 1
- Added to Heist Feed
- Publisher date