CVE-2025-39999blk-mq: fix blk_mq_tags double free while nr_requests grown
- —Not scoredno CVSS score yet
- 0.20%Exploitation in 30 daysEPSS · top 91% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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/[email protected]/
Timeline
ID reserved
By Linux
- 6 months later
· 6 months later
Published
- 7 months later
· 7 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Deferred.
- EPSS (exploitation in 30 days)
- 0.20% · top 91% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 58567d8e95c096ad234963df90a2ca518901f4b6 – < 8faee580d63bc2a54a59dcdb7f9ce4de29384fec
- affected f5a6604f7a4405450e4a1f54e5430f47290c500f – < 392b1d64911f4de8887fe8b68299fa8bd6e5b923
- affected f5a6604f7a4405450e4a1f54e5430f47290c500f – < ba28afbd9eff2a6370f23ef4e6a036ab0cfda409
- affected 6.16.4 – < 6.16.11
- affected 6.17
- unaffected < 6.17
- unaffected 6.16.11 – ≤ 6.16.*
- unaffected 6.17.1 – ≤ 6.17.*
- unaffected 6.18 – ≤ *
References
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2025-34574 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2025-39999)Record last updated .