Overview
About vulnerability
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.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , Ubuntu 20.04 ELS
- Affected packages:
- kernel-uek @ 5.4.17 (+9 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| AlmaLinux 10 | Released |
37 kernels
|
| AlmaLinux 8 | Released |
105 kernels
|
| AlmaLinux 9 | Released |
107 kernels
|
| AlmaLinux 9.2 ESU | Planned | — |
| AlmaLinux 9.6 ESU | Released |
9 kernels
|
| Amazon Linux 2023 | Planned | — |
| CentOS 7 | Released |
35 kernels
|
| CentOS 7 plus | Released |
23 kernels
|
| CentOS 8 | Released |
21 kernels
|
| CloudLinux OS 7h | Released |
102 kernels
|
| CloudLinux OS 8 | Released |
99 kernels
|
| Debian 11 | In Rollout |
37 kernels
|
| Debian 11 cloud | In Rollout |
17 kernels
|
| Debian 12 | In Rollout |
40 kernels
|
| Debian 13 | Planned | — |
| Oracle Linux 8 | Released |
115 kernels
|
| Oracle Linux 9 | Released |
109 kernels
|
| RHEL 10 | Released |
37 kernels
|
| RHEL 7 | Released |
60 kernels
|
| RHEL 8 | Released |
110 kernels
|
| RHEL 9 | Released |
105 kernels
|
| Rocky Linux 10 | Released |
27 kernels
|
| Rocky Linux 8 | Released |
88 kernels
|
| Rocky Linux 9 | Released |
86 kernels
|
| Ubuntu 22.04 | Planned | — |
| Ubuntu 24.04 | Planned | — |