CVE-2026-89588

In the Linux kernel, the following vulnerability has been resolved:

ACPI: APEI: GHES: fix ARM section length accounting after header

In ghes handle arm hw error(), after skipping the cper sec proc arm header with (err + 1), the remaining length was reduced by sizeof(err) (pointer size) instead of sizeof(*err) (structure size).

That overestimates the bytes left for cper arm err info records and can let the parser read past the CPER section when err info num is large enough relative to error data length.

Use sizeof(*err) so the length accounting matches the pointer advance and the earlier sizeof(*err) size check.