Bug 2559716 (CVE-2026-99022)

Summary: CVE-2026-99022 kernel: regulator: ltc3676: don't read the write-only HRST and CLIRQ registers
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's LTC3676 regulator driver. The driver improperly marks write-only command registers, including the hardware reset register, as readable. A local user with administrative privileges can cause a Denial of Service (DoS) by reading the regulator registers through debugfs, which unintentionally triggers an immediate hardware reset and reboots the system.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Description OSIDB Bzimport 2026-10-23 13:21:31 UTC 
In the Linux kernel, the following vulnerability has been resolved:

regulator: ltc3676: don't read the write-only HRST and CLIRQ registers

HRST (0x1e) and CLIRQ (0x1f) are write-only command strobes. Writing HRST
triggers a hard reset of the chip and writing CLIRQ clears the interrupt;
reading them returns nothing useful, and the read itself fires the command.

The result is that a plain register dump resets the board:

  cat /sys/kernel/debug/regmap/2-003c/registers

walks every readable register, hits HRST, and the board reboots.

Split the callback back in two so HRST and CLIRQ stay writable but are no
longer readable. The readable range is left unchanged
(LTC3676_BUCK1 ... LTC3676_IRQSTAT).