Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
netfilter: flowtable: strictly check for maximum number of actions
The maximum number of flowtable hardware offload actions in IPv6 is:
- ethernet mangling (4 payload actions, 2 for each ethernet address)
- SNAT (4 payload actions)
- DNAT (4 payload actions)
- Double VLAN (4 vlan actions, 2 for popping vlan, and 2 for pushing) for QinQ.
- Redirect (1 action)
Which makes 17, while the maximum is 16. But act_ct supports for tunnels actions too. Note that payload action operates at 32-bit word level, so mangling an IPv6 address takes 4 payload actions.
Update flow_action_entry_next() calls to check for the maximum number of supported actions.
While at it, rise the maximum number of actions per flow from 16 to 24 so this works fine with IPv6 setups.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , TuxCare 9.6 ESU , Ubuntu 20.04 ELS
- Affected packages:
- kernel @ 5.14.0 (+6 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 |
109 kernels
|
| AlmaLinux 9 | Released |
111 kernels
|
| AlmaLinux 9.2 ESU | Planned | — |
| Amazon Linux 2023 | Planned | — |
| CentOS 8 | Released |
15 kernels
|
| CloudLinux OS 7h | Released |
103 kernels
|
| CloudLinux OS 8 | Released |
100 kernels
|
| Debian 13 | Planned | — |
| Oracle Linux 8 | Released |
111 kernels
|
| Oracle Linux 9 | Released |
110 kernels
|
| RHEL 10 | Released |
37 kernels
|
| RHEL 8 | Released |
106 kernels
|
| RHEL 9 | Released |
109 kernels
|
| Rocky Linux 10 | Released |
27 kernels
|
| Rocky Linux 8 | Released |
91 kernels
|
| Rocky Linux 9 | Released |
89 kernels
|
| Ubuntu 22.04 | Planned | — |
| Ubuntu 24.04 | Planned | — |