CVE-2022-48929 Information

Description

In the Linux kernel the following vulnerability has been resolved:

bpf: Fix crash due to out of bounds access into reg2btf_ids.

When commit e6ac2450d6de (pf: Support bpf program calling kernel function) added kfunc support it defined reg2btf_ids as a cheap way to translate the verifier reg type to the appropriate btf_vmlinux BTF ID however commit c25b2ae13603 (pf: Replace PTR_TO_XXX_OR_NULL with PTR_TO_XXX | PTR_MAYBE_NULL) moved the __BPF_REG_TYPE_MAX from the last member of bpf_reg_type enum to after the base register types and defined other variants using type flag composition. However now the direct usage of reg->type to index into reg2btf_ids may no longer fall into __BPF_REG_TYPE_MAX range and hence lead to out of bounds access and kernel crash on dereference of bad pointer.

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Reference

https://git.kernel.org/stable/c/8c39925e98d498b9531343066ef82ae39e41adae https://git.kernel.org/stable/c/f0ce1bc9e0235dd7412240be493d7ea65ed9eadc https://git.kernel.org/stable/c/45ce4b4f9009102cd9f581196d480a59208690c1

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

NONE

Base Score

HIGH

Base Severity

5.5