Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
netfilter: bridge: release template ct on non-IP path
A bridge nftables ct zone set rule can attach a conntrack template to an skb before nf_ct_bridge_pre() sees it. For non-IPv4 and non-IPv6 EtherTypes, nf_ct_bridge_pre() currently overwrites skb->_nfct with IP_CT_UNTRACKED without releasing the existing template reference.
That makes the per-cpu template, and any temporary templates allocated for concurrent use, unreachable and leaks memory until the host runs out of slab.
Reset the skb conntrack state before marking the frame untracked so the existing template reference is dropped on the non-IP path.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Debian 10 ELS , Debian 11 ELS , TuxCare 9.6 ESU , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 4.19.0 (+5 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 12 | Planned | — |
| Debian 13 | Planned | — |
| Oracle Linux 9 UEK 7 | Planned | — |