CVE-2025-68236
Description
In the Linux kernel, the following vulnerability has been resolved:
scsi: ufs: ufs-qcom: Fix UFS OCP issue during UFS power down (PC=3)
According to UFS specifications, the power-off sequence for a UFS device includes:
- Sending an SSU command with Power_Condition=3 and await a response.
- Asserting RST_N low.
- Turning off REF_CLK.
- Turning off VCC.
- Turning off VCCQ/VCCQ2.
As part of ufs shutdown, after the SSU command completion, asserting hardware reset (HWRST) triggers the device firmware to wake up and execute its reset routine. This routine initializes hardware blocks and takes a few milliseconds to complete. During this time, the ICCQ draws a large current.
This large ICCQ current may cause issues for the regulator which is supplying power to UFS, because the turn off request from UFS driver to the regulator framework will be immediately followed by low power mode(LPM) request by regulator framework. This is done by framework because UFS which is the only client is requesting for disable. So if the rail is still in the process of shutting down while ICCQ exceeds LPM current thresholds, and LPM mode is activated in hardware during this state, it may trigger an overcurrent protection (OCP) fault in the regulator.
To prevent this, a 10ms delay is added after asserting HWRST. This allows the reset operation to complete while power rails remain active and in high-power mode.
Currently there is no way for Host to query whether the reset is completed or not and hence this the delay is based on experiments with Qualcomm UFS controllers across multiple UFS vendors.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
In the Linux kernel, a fix for UFS power-down adds a 10ms delay after hardware reset to prevent regulator overcurrent protection faults.
Vulnerability
Description
A power-down sequence issue in the Qualcomm UFS driver (ufs-qcom) can trigger an overcurrent protection (OCP) fault in the regulator supplying power to the UFS device. According to UFS specifications, after sending an SSU command with Power_Condition=3, the host asserts hardware reset (HWRST) to place the device in a low-power state. However, the device firmware's reset routine draws a large current (ICCQ) for several milliseconds. If the regulator is turned off immediately after the reset is asserted, the rapid transition to low-power mode (LPM) while current is still high can cause an OCP fault [1].
Exploitation
Conditions
This vulnerability occurs during the UFS shutdown sequence, specifically after the SSU command completes and the host asserts HWRST. No authentication or special privileges are needed; it is triggered by normal system shutdown or power management operations. The issue affects systems using Qualcomm UFS controllers and certain regulators that enable LPM when all clients disable the rail [1].
Impact
An attacker with the ability to trigger a UFS power-down (e.g., via system shutdown) could cause the regulator to trip its overcurrent protection, potentially leading to platform instability, unexpected power loss, or damage to the regulator. This could result in denial of service or hardware failure [1].
Mitigation
The fix, committed in the Linux kernel stable branch, adds a 10ms delay after asserting HWRST before turning off power rails. This delay allows the reset routine to complete while the rails remain in high-power mode, preventing the OCP condition. The patch is available in kernel commit [1]. Users should apply the updated kernel to mitigate the issue.
AI Insight generated on May 19, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.
Affected products
2Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
2News mentions
0No linked articles in our index yet.