AZL-84222
See a problem?- Import Source
- https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-84222.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/AZL-84222
- Upstream
- Published
- 2026-04-25T09:16:02Z
- Modified
- 2026-08-28T17:47:43Z
- 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
tcf_csum_act() walks nested VLAN headers directly from skb->data when an skb still carries in-payload VLAN tags. The current code reads vlan->h_vlan_encapsulated_proto and then pulls VLAN_HLEN 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 h_vlan_encapsulated_proto reads past the linear area, and the following skb_pull(VLAN_HLEN) may violate skb invariants.
Fix this by requiring pskb_may_pull(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