CVE-2025-21908

CVE-2025-21908 concerns the Linux kernel NFS subsystem. The issue arises when nfs_release_folio() can deadlock during writeback initiated by kcompactd, triggering a recursive path through NFS and the NFSD loopback on the same host. The patch adds PF_KCOMPACTD and a current_is_kcompactd() helper t...