CVE-2026-31741counter: rz-mtu3-cnt: prevent counter from being toggled multiple times
- 5.5MediumCVSS base score
- 0.12%Exploitation in 30 daysEPSS · top 98% 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: counter: rz-mtu3-cnt: prevent counter from being toggled multiple times Runtime PM counter is incremented / decremented each time the sysfs enable file is written to. If user writes 0 to the sysfs enable file multiple times, runtime PM usage count underflows, generating the following message. rz-mtu3-counter rz-mtu3-counter.0: Runtime PM usage count underflow! At the same time, hardware registers end up being accessed with clocks off in rz_mtu3_terminate_counter() to disable an already disabled channel. If user writes 1 to the sysfs enable file multiple times, runtime PM usage count will be incremented each time, requiring the same number of 0 writes to get it back to 0. If user writes 0 to the sysfs enable file while PWM is in progress, PWM is stopped without counter being the owner of the underlying MTU3 channel. Check against the cached count_is_enabled value and exit if the user is trying to set the same enable value.
Timeline
ID reserved
By Linux
- 53 days later
· 53 days later
Published
- 10 days later
· 10 days 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
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.12% · top 98% of all CVEs (14 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
- affected 0be8907359df4c62319f5cb2c6981ff0d9ebf35a – < 885aa739a07ab45e90dfa997205acec97979ce4e
- affected 0be8907359df4c62319f5cb2c6981ff0d9ebf35a – < ced8b48420eddb1251f93c22dc23fa136490b3cd
- affected 0be8907359df4c62319f5cb2c6981ff0d9ebf35a – < e07237df8538b0ae98dce112e4f6db093d767f80
- affected 0be8907359df4c62319f5cb2c6981ff0d9ebf35a – < f5f6f06d7e6d262026578b59ba7426eb04acce5d
- affected 0be8907359df4c62319f5cb2c6981ff0d9ebf35a – < 67c3f99bed6f422ba343d2b70a2eeeccdfd91bef
- affected 6.4
- unaffected < 6.4
- unaffected 6.6.134 – ≤ 6.6.*
- unaffected 6.12.81 – ≤ 6.12.*
- unaffected 6.18.22 – ≤ 6.18.*
- unaffected 6.19.12 – ≤ 6.19.*
- unaffected 7.0 – ≤ *
References
References5
- https://git.kernel.org/stable/c/885aa739a07ab45e90dfa997205acec97979ce4e (opens in a new tab)
- https://git.kernel.org/stable/c/ced8b48420eddb1251f93c22dc23fa136490b3cd (opens in a new tab)
- https://git.kernel.org/stable/c/e07237df8538b0ae98dce112e4f6db093d767f80 (opens in a new tab)
- https://git.kernel.org/stable/c/f5f6f06d7e6d262026578b59ba7426eb04acce5d (opens in a new tab)
- https://git.kernel.org/stable/c/67c3f99bed6f422ba343d2b70a2eeeccdfd91bef (opens in a new tab)
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-2026-26554 (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-2026-31741)Record last updated .