Import Source
https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-84222.json
JSON Data
https://api.osv.dev/v1/vulns/AZL-84222
Upstream
Published
2026-04-25T09:16:02Z
Modified
2026-08-28T17:48:03.448086288Z
Summary
CVE-2026-31684 affecting package kernel for versions less than 6.6.137.1-1
Details

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

net: sched: act_csum: validate nested VLAN headers

tcfcsumact() walks nested VLAN headers directly from skb->data when an skb still carries in-payload VLAN tags. The current code reads vlan->hvlanencapsulatedproto and then pulls VLANHLEN bytes without first ensuring that the full VLAN header is present in the linear area.

If only part of an inner VLAN header is linearized, accessing hvlanencapsulatedproto reads past the linear area, and the following skbpull(VLAN_HLEN) may violate skb invariants.

Fix this by requiring pskbmaypull(skb, VLAN_HLEN) before accessing and pulling each nested VLAN header. If the header still is not fully available, drop the packet through the existing error path.

References

Affected packages

Azure Linux:3 / kernel

Package

Name
kernel
Purl
pkg:rpm/azure-linux/kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
6.6.137.1-1

Database specific

source
"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-84222.json"