In the Linux kernel, the following vulnerability has been resolved: regulator: ltc3676: don't read the write-only HRST and CLIRQ registers HRST… (CVE-2026-99022)

The Linux kernel's regulator driver for the LTC3676 device improperly allowed reading of two write-only command strobe registers: HRST (0x1e) and CLIRQ (0x1f). Writing HRST triggers a hard reset of the chip, and writing CLIRQ clears interrupts. Reading these registers returns no useful data but triggers the command, causing a board reset during a register dump operation. The fix involved splitting the register access callbacks to keep HRST and CLIRQ writable but not readable, preventing unintended resets while leaving the readable register range unchanged.

Attempting to read the HRST and CLIRQ registers causes the hardware to reset, which can disrupt system operation and cause unexpected reboots. This affects any process that performs a register dump including these addresses, potentially leading to denial of service or system instability.

A fix is available that modifies the driver to prevent reads of the HRST and CLIRQ write-only registers, avoiding unintended resets. Users should apply the updated Linux kernel version containing this fix. No additional mitigation is required once the patch is applied.