CVE-2024-46764

What it actually does

The flaw permits a BTF section name of length 1 consisting solely of a null byte to bypass the validation check in btf_name_valid_section(), returning true and enabling an out-of-bounds access during subsequent processing of the invalid name.

Why it matters to the business

Organizations running affected Linux kernels face elevated risk of kernel instability or crashes when loading BPF programs that carry BTF metadata, which can disrupt networking, observability, and security tooling that depends on eBPF; the issue affects a widely deployed kernel component with many downstream dependents.

How an attack unfolds

An attacker crafts a minimal BTF structure containing a single-byte null name, submits it through the BPF program load path, and relies on the missing null-byte and printable-character checks to have the invalid name accepted, after which further kernel processing triggers the out-of-bounds condition.

How to fix it

Upgrade the Linux kernel to commit c8ffe2d4d37a05ce18c71b87421443c16f8475e5 or an equivalent stable branch containing the added null-byte and printable-character checks; for yaklang update to version 1.2.4-sp2.

How to confirm the fix worked

Confirm the patched btf_name_valid_section() implementation explicitly rejects a name whose first byte is null or non-printable; recompile a test kernel and attempt to load a BTF object with a single-null-byte name to verify rejection.

Typical attack path

1. Locate a target system that accepts unprivileged or privileged BPF program loads with BTF information
2. Construct a BPF object whose BTF section name is exactly one null byte
3. Invoke bpf() syscall or equivalent loader to pass the object through btf_name_valid_section()
4. Trigger continued verifier or BTF parsing logic that performs the out-of-bounds operation

How to detect it

Review kernel logs for oops or panic entries referencing btf_name_valid_section or BTF name handling; inspect audit trails or BPF event logs for program loads that specify unusually short or empty section names.

What your security team should do

• Apply the kernel fix to all production systems within the normal change window, treating it as a stability update for any environment that uses eBPF
• Audit custom or third-party BPF programs for BTF section names that could be malformed
• Enable kernel panic and oops logging to detect any post-patch anomalies