CVE-2025-39999: blk-mq: fix blk_mq_tags double free while nr_requests grown

Deferred
AliasesUBUNTU-CVE-2025-39999DEBIAN-CVE-2025-39999
Published 15-10-2025Last modified 23-05-2026

Vulnerability summary

CVE-2025-39999 is a vulnerability in linux with no CVSS score yet. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 9.4% of scored vulnerabilities.

Priority
Insufficient evidence

No CVSS vector published; no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
Not scored
010
No CVSS score recorded
EPSS score
0.20%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 2 · Related 2
OPENSUSE-SU-2025:15671-1OPENSUSE-SU-2026:10301-1

Timeline

  1. 15-10-2025
    PublishedVulnerability first disclosed.
  2. 23-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: blk-mq: fix blk_mq_tags double free while nr_requests grown In the case user trigger tags grow by queue sysfs attribute nr_requests, hctx->sched_tags will be freed directly and replaced with a new allocated tags, see blk_mq_tag_update_depth(). The problem is that hctx->sched_tags is from elevator->et->tags, while et->tags is still the freed tags, hence later elevator exit will try to free the tags again, causing kernel panic. Fix this problem by replacing et->tags with new allocated tags as well. Noted there are still some long term problems that will require some refactor to be fixed thoroughly[1]. [1] https://lore.kernel.org/all/20250815080216.410665-1-yukuai1@huaweicloud.com/

CVSS metrics

Risk metrics not yet published.

EPSS trend

Probability

0.20%

Chance of exploitation in the next 30 days

Percentile

9%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.20% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: not stated in public data.

Ubuntu87 products
  • linux< 6.17.0-6.6
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 6.17.0-1003.3
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.16.11-1
Linux1 product
  • linux≥ 58567d8e95c096ad234963df90a2ca518901f4b6, < 8faee580d63bc2a54a59dcdb7f9ce4de29384fec | ≥ f5a6604f7a4405450e4a1f54e5430f47290c500f, < 392b1d64911f4de8887fe8b68299fa8bd6e5b923 | ≥ f5a6604f7a4405450e4a1f54e5430f47290c500f, < ba28afbd9eff2a6370f23ef4e6a036ab0cfda409 | ≥ 6.16.4, < 6.16.11 | 6.17

3 vendors · 89 products

References

7 links