CVE-2025-21908 — Improper Locking in Linux
Severity
5.5MEDIUMNVD
OSV5.9OSV4.7
EPSS
0.1%
top 84.58%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
Timeline
PublishedApr 1
Latest updateOct 15
Description
In the Linux kernel, the following vulnerability has been resolved:
NFS: fix nfs_release_folio() to not deadlock via kcompactd writeback
Add PF_KCOMPACTD flag and current_is_kcompactd() helper to check for it so
nfs_release_folio() can skip calling nfs_wb_folio() from kcompactd.
Otherwise NFS can deadlock waiting for kcompactd enduced writeback which
recurses back to NFS (which triggers writeback to NFSD via NFS loopback
mount on the same host, NFSD blocks waiting for XFS's call to
__filemap_…
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitability: 1.8 | Impact: 3.6