CVE-2022-49873

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix wrong reg type conversion in release_reference() Some helper functions will allocate memory. To avoid memory leaks, the verifier requires the eBPF program to release these memories by calling the corresponding helper functions. When a resource is released, all pointer registers corresponding to the resource should be invalidated. The verifier use release_references() to do this job, by apply __mark_reg_unknown() to each relevant register. It will give these registers the type of SCALAR_VALUE. A register that will contain a pointer value at runtime, but of type SCALAR_VALUE, which may allow the unprivileged user to get a kernel pointer by storing this register into a map. Using __mark_reg_not_init() while NOT allow_ptr_leaks can mitigate this problem.

Predictions

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

References

• https://access.redhat.com/errata/RHSA-2023:6583
• https://www.suse.com/security/cve/CVE-2022-49873.html
• https://security-tracker.debian.org/tracker/CVE-2022-49873