CVE-2022-49873 — bpf: Fix wrong reg type conversion in release_reference()
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 av…
Published: 2025-05-01 · CVSS: 5.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7