CVE-2024-26761

Description

In the Linux kernel, the following vulnerability has been resolved:cxl/pci: Fix disabling memory if DVSEC CXL Range does not match a CFMWS windowThe Linux CXL subsystem is built on the assumption that HPA == SPA.That is, the host physical address (HPA) the HDM decoder registers areprogrammed with are system physical addresses (SPA).During HDM decoder setup, the DVSEC CXL range registers (cxl-3.1,8.1.3.8) are checked if the memory is enabled and the CXL range is ina HPA window that is described in a CFMWS structure of the CXL hostbridge (cxl-3.1, 9.18.1.3).Now, if the HPA is not an SPA, the CXL range does not match a CFMWSwindow and the CXL memory range will be disabled then. The HDM decoderstops working which causes system memory being disabled and further asystem hang during HDM decoder initialization, typically when a CXLenabled kernel boots.Prevent a system hang and do not disable the HDM decoder if thedecoders CXL range is not found in a CFMWS window.Note the change only fixes a hardware hang, but does not implementHPA/SPA translation. Support for this can be added in a follow onpatch series.

Risk Information

Associated Vulnerability

Patch Details

References

https://nvd.nist.gov/vuln/detail/CVE-2023-1234
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-1234