Answer in brief
CVE-2025-38338 records a High severity (CVSS 7.8) vulnerability in fs/nfs/read: fix double-unlock bug in nfs_return_empty_folio(). The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=000dbe0bec058cbf2ca9e156e4a5584f5158b0f9 <14f5549ad163be2c018abc1bb38370fff617a243 || >=000dbe0bec058cbf2ca9e156e4a5584f5158b0f9 <5bf0b9eeb0174686f22c2e5b8fb9f47ad25da6f5 || >=000dbe0bec058cbf2ca9e156e4a5584f5158b0f9 <1e93b61d3eaa14bfebcc2716ac09d43f3845d420 || >=000dbe0bec058cbf2ca9e156e4a5584f5158b0f9 <4c10fa44bc5f700e2ea21de2fbae520ba21f19d9 | 14f5549ad163be2c018abc1bb38370fff617a243, 5bf0b9eeb0174686f22c2e5b8fb9f47ad25da6f5, 1e93b61d3eaa14bfebcc2716ac09d43f3845d420, 4c10fa44bc5f700e2ea21de2fbae520ba21f19d9 |
| Linux/Linuxgeneric | 6.4 | Not reported |
Published upstream
Jul 10, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 5, 2026
In the Linux kernel, the following vulnerability has been resolved: fs/nfs/read: fix double-unlock bug in nfs_return_empty_folio() Sometimes, when a file was read while it was being truncated by another NFS client, the kernel could deadlock because folio_unlock() was called twice, and the second call would XOR back the `PG_locked` flag. Most of the time (depending on the timing of the truncation), nobody notices the problem because folio_unlock() gets called three times, which flips `PG_locked` back off: 1. vfs_read, nfs_read_folio, ... nfs_read_add_folio, nfs_return_empty_folio 2. vfs_read, nfs_read_folio, ... netfs_read_collection, netfs_unlock_abandoned_read_pages 3. vfs_read, ... nfs_do_read_folio, nfs_read_add_folio, nfs_return_empty_folio The problem is that nfs_read_add_folio() is not supposed to unlock the folio if fscache is enabled, and a nfs_netfs_folio_unlock() check is missing in nfs_return_empty_folio(). Rarely this leads to a warning in netfs_read_collection(): ------------[ cut here ]------------ R=0000031c: folio 10 is not locked WARNING: CPU: 0 PID: 29 at fs/netfs/read_collect.c:133 netfs_read_collection+0x7c0/0xf00 [...] Workqueue: events_unbound netfs_read_collection_worker RIP: 0010:netfs_read_collection+0x7c0/0xf00 [...] Call Trace: <TASK> netfs_read_collection_worker+0x67/0x80 process_one_work+0x12e/0x2c0 worker_thread+0x295/0x3a0 Most of the time, however, processes just get stuck forever in folio_wait_bit_common(), waiting for `PG_locked` to disappear, which never happens because nobody is really holding the folio lock.
Quoted source text, attributed separately from HOL analysis.