CVE-2024-58060

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

bpf: Reject struct_ops registration that uses module ptr and the module btf_id is missing

There is a UAF report in the bpf_struct_ops when CONFIG_MODULES=n.

In particular, the report is on tcp_congestion_ops that has

a "struct module *owner" member.

For struct_ops that has a "struct module *owner" member,

it can be extended either by the regular kernel module or

by the bpf_struct_ops. bpf_try_module_get() will be used

to do the refcounting and different refcount is done

based on the owner pointer. When CONFIG_MODULES=n,

the btf_id of the "struct module" is missing:

WARN: resolve_btfids: unresolved symbol module

Thus, the bpf_try_module_get() cannot do the correct refcounting.

Not all subsystem's struct_ops requires the "struct module *owner" member.

e.g. the recent sched_ext_ops.

This patch is to disable bpf_struct_ops registration if

the struct_ops has the "struct module *" member and the

"struct module" btf_id

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References