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CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2025-38614MEDIUM
Linux Linux — eventpoll: Fix semi-unbounded recursion
  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   L   L   N  U  N  N  H    5.5   .0017    7.0     —
AFFECTED
  Product  Versions                                    Fixed
  Linux    22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e –  —
  Linux    2.6.38 –                                    5.15.190
TIMELINE
  Apr 16  Reserved by Linux
  Aug 19  Published (CNA: Linux)
  Jul 30  RESCORED — CVE-2025-38614 (Linux). CVSS 7.8 → 5.5 (NVD).
CWE-674 · CNA: Linux · CVSS v3.1 · 11 references · NVD status: Modified

Description

In the Linux kernel, the following vulnerability has been resolved: eventpoll: Fix semi-unbounded recursion Ensure that epoll instances can never form a graph deeper than EP_MAX_NESTS+1 links. Currently, ep_loop_check_proc() ensures that the graph is loop-free and does some recursion depth checks, but those recursion depth checks don't limit the depth of the resulting tree for two reasons: - They don't look upwards in the tree. - If there are multiple downwards paths of different lengths, only one of the paths is actually considered for the depth check since commit 28d82dc1c4ed ("epoll: limit paths"). Essentially, the current recursion depth check in ep_loop_check_proc() just serves to prevent it from recursing too deeply while checking for loops. A more thorough check is done in reverse_path_check() after the new graph edge has already been created; this checks, among other things, that no paths going upwards from any non-epoll file with a length of more than 5 edges exist. However, this check does not apply to non-epoll files. As a result, it is possible to recurse to a depth of at least roughly 500, tested on v6.15. (I am unsure if deeper recursion is possible; and this may have changed with commit 8c44dac8add7 ("eventpoll: Fix priority inversion problem").) To fix it: 1. In ep_loop_check_proc(), note the subtree depth of each visited node, and use subtree depths for the total depth calculation even when a subtree has already been visited. 2. Add ep_get_upwards_depth_proc() for similarly determining the maximum depth of an upwards walk. 3. In ep_loop_check(), use these values to limit the total path length between epoll nodes to EP_MAX_NESTS edges.

Lifecycle

Complete event history — 3 events, chronological
DateEventDetail
April 16, 2025ReservedReserved by Linux
August 19, 2025PublishedPublished (CNA: Linux)
July 30, 2026RESCOREDRESCORED — CVE-2025-38614 (Linux). CVSS 7.8 → 5.5 (NVD).

Affected

Affected products and packages — 2 rows
VendorProduct / PackageEcosystemVersion introducedFixed
LinuxLinux22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e
LinuxLinux2.6.385.15.190

Weaknesses

CWE-674

References (11)

Related

Authoritative record: CVE-2025-38614 at cve.org

Vendors: linux

Weaknesses: CWE-674

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2025-38614 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.