CVE-2026-31741
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.1% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.1% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.1% · EPSS, next 30 days
- Record status
- Analyzed
Affected
- Linux Kernel < 6.6.134
- Linux Kernel < 6.12.81
- Linux Kernel < 6.18.22
- Linux Kernel < 6.19.12
- Linux Kernel 7.0
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-31741.md and follow it. Check whether this project is affected by CVE-2026-31741. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/67c3f99bed6f422ba343d2b70a2eeeccdfd91bef
- https://git.kernel.org/stable/c/885aa739a07ab45e90dfa997205acec97979ce4e
- https://git.kernel.org/stable/c/ced8b48420eddb1251f93c22dc23fa136490b3cd
- https://git.kernel.org/stable/c/e07237df8538b0ae98dce112e4f6db093d767f80
- https://git.kernel.org/stable/c/f5f6f06d7e6d262026578b59ba7426eb04acce5d
References
- https://git.kernel.org/stable/c/67c3f99bed6f422ba343d2b70a2eeeccdfd91bef
- https://git.kernel.org/stable/c/885aa739a07ab45e90dfa997205acec97979ce4e
- https://git.kernel.org/stable/c/ced8b48420eddb1251f93c22dc23fa136490b3cd
- https://git.kernel.org/stable/c/e07237df8538b0ae98dce112e4f6db093d767f80
- https://git.kernel.org/stable/c/f5f6f06d7e6d262026578b59ba7426eb04acce5d