Advisory [CVE-2026-64087] (pmbus/adm1266) reject implausible blackbox record_count
This security Red Hat Linux advisory covers CVE-2026-64087.
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Summary
In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/adm1266) reject implausible blackbox record_count adm1266_nvmem_read_blackbox() loops over a record_count that comes straight from byte 3 of the BLACKBOX_INFO response.
The destination buffer is data->dev_mem, sized for the nvmem cell's declared 2048 bytes (ADM1266_BLACKBOX_MAX_RECORDS * ADM1266_BLACKBOX_SIZE = 32 * 64).
A device that reports a record_count greater than 32 -- whether due to firmware bugs, bus corruption, or a non-responsive slave returning 0xff -- would walk read_buff past the end of the dev_mem allocation on the trailing iterations.
Cap record_count at ADM1266_BLACKBOX_MAX_RECORDS (introduced here) before entering the loop and return -EIO on any larger value, so a malformed BLACKBOX_INFO response cannot drive the loop out of bounds. A malformed response from a hardware monitoring device could cause the driver to read beyond the allocated memory buffer.
This out-of-bounds read can lead to system instability or denial of service. Red Hat severity: not rated.
Weakness: CWE-125. Red Hat lists Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9 as not affected.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 7 days ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 7 days ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 7 days ago·verify at source
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