Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: fix fragment reassembly length accounting
batman-adv keeps a running payload length for queued fragments and uses it to validate a fragment chain before reassembly.
That accounting currently allows the accumulated fragment length to be truncated during updates. As a result, malformed fragment chains can bypass the intended validation and drive reassembly with inconsistent length state, leading to a local denial of service.
Fix the accounting by storing the accumulated length in a length-typed field and rejecting update overflows before the existing validation logic runs.
The fix was verified against the original reproducer and against valid fragment reassembly paths.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Debian 10 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- kernel @ 5.10.0 (+12 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 11 | Planned | — |
| Debian 11 cloud | Planned | — |
| Debian 12 | Planned | — |
| Ubuntu 16.04 AWS HWE ESM | Planned | — |
| Ubuntu 16.04 HWE ESM | Planned | — |
| Ubuntu 18.04 | Planned | — |
| Ubuntu 20.04 | Planned | — |
| Ubuntu 22.04 | Planned | — |
| Ubuntu 24.04 | Planned | — |
| Ubuntu 24.04 AWS | Planned | — |