CVE-2026-89731

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

cxl/ras: Fix cxl_rch_get_aer_info() out-of-bounds AER register read

cxl_rch_get_aer_info() copies the RCH Downstream Port AER capability from

the RCRB MMIO block using a readl() loop bounded by sizeof(struct

aer_capability_regs). This struct is a software layout and its embedded

struct pcie_tlp_log is larger than the on-wire AER capability. As a

result the loop reads past the mapped AER register block.

The over-read also populates the software-only tail fields including

header_log.header_len. An out-of-range header_len passed to

pcie_print_tlp_log() can then loop past the header log buffer and cause

a second out-of-bounds read.

The read was correct when introduced, but struct pcie_tlp_log has since

grown (Header Log and TLP Prefix Log sizes, header_len and flit fields),

so sizeof(struct aer_capability_regs) no longer matches the physical AER

capability.

Bound the read to the physical AER registers, header through the 16 byte

Header Log. Zero the destination first so the software-only fields are

deterministic.