Bug 2513447 (CVE-2026-68340)

Summary: CVE-2026-68340 kernel: hwmon: occ: validate poll response sensor blocks
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerability-draftAssignee: Product Security <prodsec-ir-bot>
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Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's hwmon OCC (OpenPOWER Abbreviated Command and Control) poll response parser. This vulnerability occurs because the parser incorrectly uses a static array capacity as the boundary for sensor data blocks instead of the actual data length. A specially crafted, truncated response could cause the parser to read data beyond the intended buffer, potentially leading to memory corruption or a denial of service.
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Description OSIDB Bzimport 2026-08-10 12:37:53 UTC
In the Linux kernel, the following vulnerability has been resolved:

hwmon: occ: validate poll response sensor blocks

The OCC poll response parser walks a counted list of sensor data blocks.
It used the static backing-array capacity as the parse boundary, but a
transport response makes only data_length bytes current and valid. A
truncated response can therefore make the parser consume a block header or
block extent outside the current response.

Use data_length as the parent boundary, prove the fixed poll header and
each current block header before reading them, and prove the complete block
before advancing. Keep parsed sensor metadata local until the complete
response has passed validation, then publish it. Propagate
malformed-response errors before publishing the OCC as active.

Comment 1 Mauro Matteo Cascella 2026-08-11 12:00:14 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081037-CVE-2026-68340-beaa@gregkh/T