CVE-2026-53085 bpf: fix mm lifecycle in open-coded task_vma iterator

In the Linux kernel, the following vulnerability has been resolved: bpf: fix mm lifecycle in open-coded taskvma iterator The open-coded taskvma iterator reads task-mm locklessly and acquires mmapreadtrylock but never calls mmget. If the task exits concurrently, the mmstruct can be freed as it is...