CVE-2026-93112bpf: Require a BPF cpumask for bpf_cpumask_populate()

Official description

In the Linux kernel, the following vulnerability has been resolved: bpf: Require a BPF cpumask for bpf_cpumask_populate() bpf_cpumask_populate() writes to its destination with bitmap_copy(), but the destination is typed as struct cpumask *. That allows the verifier to accept borrowed cpumask pointers returned by read-only kfuncs, such as scx_bpf_get_online_cpumask(), as a writable destination. Make the destination a struct bpf_cpumask * so populate follows the same ownership rule as the other mutating cpumask kfuncs. Query kfuncs continue to accept const struct cpumask * inputs.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/0cfc9348a045da64955af2dd6902e66dfc7d6469
• https://git.kernel.org/stable/c/b7e2a5c6519adc73be55c3de2cb545e095a0fbc5
• https://git.kernel.org/stable/c/8740156ad33be5071b588b594c55f279457f667c