title: cxl/pci: Fix disabling memory if DVSEC CXL Range does not match a CFMWS window
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 window
The Linux CXL subsystem is built on the assumption that HPA == SPA.
That is, the host physical address (HPA) the HDM decoder registers are
programmed 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 in
a HPA window that is described in a CFMWS structure of the CXL host
bridge (cxl-3.1, 9.18.1.3).
Now, if the HPA is not an SPA, the CXL range does not match a CFMWS
window and the CXL memory range will be disabled then. The HDM decoder
stops working which causes system memory being disabled and further a
system hang during HDM decoder initialization, typically when a CXL
enabled kernel boots.
Prevent a system hang and do not disable the HDM decoder if the
decoder's CXL range is not found in a CFMWS window.
Note the change only fixes a hardware hang, but does not implement
HPA/SPA translation. Support for this can be added in a follow on
patch series.
affected:
{
product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 34e37b4c432c, lessThan: 031217128990, status: affected, versionType: git
version: 34e37b4c432c, lessThan: 2cc1a530ab31, status: affected, versionType: git
version: 34e37b4c432c, lessThan: 3a3181a71935, status: affected, versionType: git
version: 34e37b4c432c, lessThan: 0cab68720598, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 5.19, status: affected
version: 0, lessThan: 5.19, status: unaffected, versionType: custom
version: 6.1.80, lessThanOrEqual: 6.1.*, status: unaffected, versionType: custom
version: 6.6.19, lessThanOrEqual: 6.6.*, status: unaffected, versionType: custom
version: 6.7.7, lessThanOrEqual: 6.7.*, status: unaffected, versionType: custom
version: 6.8, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
