Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
net: Fix TOCTOU issue in sk_is_readable()
sk->sk_prot->sock_is_readable is a valid function pointer when sk resides in a sockmap. After the last sk_psock_put() (which usually happens when socket is removed from sockmap), sk->sk_prot gets restored and sk->sk_prot->sock_is_readable becomes NULL.
This makes sk_is_readable() racy, if the value of sk->sk_prot is reloaded after the initial check. Which in turn may lead to a null pointer dereference.
Ensure the function pointer does not turn NULL after the check.
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 20.04 ELS
- Affected packages:
- kernel @ 4.18.0 (+8 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| AlmaLinux 9.2 ESU | Planned | — |
| AlmaLinux 9.6 ESU | Planned | — |
| Amazon Linux 2023 | Planned | — |
| Debian 11 | Planned | — |
| Debian 11 cloud | Planned | — |
| Debian 12 | Released |
28 kernels
|
| Oracle Linux 8 UEK 7 | In Progress | — |
| Oracle Linux 9 UEK 7 | In Progress | — |
| Proxmox VE 7 5.15 | Released |
47 kernels
|
| Ubuntu 20.04 HWE AWS | Released |
57 kernels
|
| Ubuntu 20.04 HWE Azure | Released |
40 kernels
|
| Ubuntu 22.04 | Released |
81 kernels
|
| Ubuntu 22.04 AWS | Released |
72 kernels
|
| Ubuntu 22.04 Azure | Released |
66 kernels
|
| Ubuntu 24.04 | Planned | — |