CVE-2026-93276 phy: renesas: phy-rcar-gen3-usb2: Fix devm action registration for disabled VBUS regulator
A flaw in the Renesas USB2 PHY driver causes a kernel warning and potential instability during device removal due to incorrect regulator cleanup logic.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-93276?
CVE-2026-93276 is a denial of service vulnerability in Linux, published on 24 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
phy: renesas: phy-rcar-gen3-usb2: Fix devm action registration for disabled VBUS regulator
devm_regulator_get_exclusive() initialises the regulator with enable_count = 1, requiring the consumer to disable it before release.
The devm disable action was previously only registered when the caller explicitly requested enable, so when the regulator was left in its initial enabled state without an explicit enable call, the cleanup path skipped decrementing enable_count, triggering a WARN_ON during regulator release on device removal.
Fix this by always registering the devm disable action based on the actual enabled state via regulator_is_enabled(), regardless of whether the caller requested an explicit enable. This covers both the explicitly enabled case and the initial state set by devm_regulator_get_exclusive().
Which versions are affected by CVE-2026-93276?
How do I fix CVE-2026-93276?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-93276 being exploited?
There is no known exploitation of CVE-2026-93276 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-93276, DEBIAN-CVE-2026-93276, GHSA-gfvh-9676-44ch, UBUNTU-CVE-2026-93276.