Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
security/keys: fix missed RCU read section on lookup
Nicholas Carlini reports that the keyring code calls assoc_array_find() in find_key_to_update() without holding the RCU read lock, while the assoc_array_gc() code really is designed around removing the node from the tree and then freeing it after an RCU grace-period.
The regular key handling doesn’t see this because holding the keyring semaphore hides any lifetime issues, but the persistent key handling uses a different model.
Instead of extending the keyring locking, just do the simple RCU locking that the assoc_array was designed for.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Debian 10 ELS , Debian 11 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- kernel @ 5.14.0 (+12 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| AlmaLinux 10 | In Rollout |
63 kernels
|
| Amazon Linux 2023 | Planned | — |
| Debian 12 | Planned | — |
| Oracle Linux 10 | In Rollout |
49 kernels
|
| RHEL 10 | In Rollout |
64 kernels
|
| RHEL 8 | Planned | — |
| RHEL 9 | Planned | — |
| Rocky Linux 10 | In Rollout |
47 kernels
|
| Ubuntu 24.04 | Planned | — |