Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
net/sched: act_ct: preserve tc_skb_cb across defragmentation
tcf_ct_handle_fragments() calls nf_ct_handle_fragments() without saving and restoring skb->cb. The defrag helper clears IPCB/IP6CB, which aliases the tc_skb_cb/qdisc_skb_cb control buffer. Fragmented traffic through act_ct therefore loses qdisc metadata such as pkt_segs and can trigger WARN_ON_ONCE() in qdisc_pkt_segs() when panic_on_warn is enabled.
Save and restore the full tc_skb_cb around nf_ct_handle_fragments(), matching the pattern used by ovs_ct_handle_fragments().
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Debian 10 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU
- Affected packages:
- linux @ 4.19.0 (+6 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 12 | Planned | — |
| Debian 13 | Released |
13 kernels
|
| Oracle Linux 8 UEK 7 | Released |
112 kernels
|
| Oracle Linux 9 UEK 7 | Released |
112 kernels
|
| Ubuntu 24.04 | Planned | — |
| Ubuntu 24.04 AWS | Planned | — |
| Ubuntu 26.04 | Released |
2 kernels
|