Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
bpf: reject direct access to nullable PTR_TO_BUF pointers
check_mem_access() matches PTR_TO_BUF via base_type() which strips PTR_MAYBE_NULL, allowing direct dereference without a null check.
Map iterator ctx->key and ctx->value are PTR_TO_BUF | PTR_MAYBE_NULL. On stop callbacks these are NULL, causing a kernel NULL dereference.
Add a type_may_be_null() guard to the PTR_TO_BUF branch, matching the existing PTR_TO_BTF_ID pattern.
Details
- Affected product:
- Ubuntu 20.04 ELS
- Affected packages:
- linux-meta @ 5.4.0
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Amazon Linux 2023 | Planned | — |
| Debian 13 | Planned | — |
| Ubuntu 22.04 | Planned | — |
| Ubuntu 24.04 | Planned | — |