ghsa-wxj8-5gp5-wmxf
Vulnerability from github
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": [],
"aliases": [
"CVE-2024-26761"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-04-03T17:15:52Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncxl/pci: Fix disabling memory if DVSEC CXL Range does not match a CFMWS window\n\nThe Linux CXL subsystem is built on the assumption that HPA == SPA.\nThat is, the host physical address (HPA) the HDM decoder registers are\nprogrammed with are system physical addresses (SPA).\n\nDuring HDM decoder setup, the DVSEC CXL range registers (cxl-3.1,\n8.1.3.8) are checked if the memory is enabled and the CXL range is in\na HPA window that is described in a CFMWS structure of the CXL host\nbridge (cxl-3.1, 9.18.1.3).\n\nNow, if the HPA is not an SPA, the CXL range does not match a CFMWS\nwindow and the CXL memory range will be disabled then. The HDM decoder\nstops working which causes system memory being disabled and further a\nsystem hang during HDM decoder initialization, typically when a CXL\nenabled kernel boots.\n\nPrevent a system hang and do not disable the HDM decoder if the\ndecoder\u0027s CXL range is not found in a CFMWS window.\n\nNote the change only fixes a hardware hang, but does not implement\nHPA/SPA translation. Support for this can be added in a follow on\npatch series.",
"id": "GHSA-wxj8-5gp5-wmxf",
"modified": "2024-04-03T18:30:42Z",
"published": "2024-04-03T18:30:42Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-26761"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/031217128990d7f0ab8c46db1afb3cf1e075fd29"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0cab687205986491302cd2e440ef1d253031c221"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2cc1a530ab31c65b52daf3cb5d0883c8b614ea69"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3a3181a71935774bda2398451256d7441426420b"
}
],
"schema_version": "1.4.0",
"severity": []
}