ghsa-r4ww-r2x2-fj39
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
x86/fpu: Keep xfd_state in sync with MSR_IA32_XFD
Commit 672365477ae8 ("x86/fpu: Update XFD state where required") and commit 8bf26758ca96 ("x86/fpu: Add XFD state to fpstate") introduced a per CPU variable xfd_state to keep the MSR_IA32_XFD value cached, in order to avoid unnecessary writes to the MSR.
On CPU hotplug MSR_IA32_XFD is reset to the init_fpstate.xfd, which wipes out any stale state. But the per CPU cached xfd value is not reset, which brings them out of sync.
As a consequence a subsequent xfd_update_state() might fail to update the MSR which in turn can result in XRSTOR raising a #NM in kernel space, which crashes the kernel.
To fix this, introduce xfd_set_state() to write xfd_state together with MSR_IA32_XFD, and use it in all places that set MSR_IA32_XFD.
{
"affected": [],
"aliases": [
"CVE-2024-35801"
],
"database_specific": {
"cwe_ids": [
"CWE-416"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-05-17T14:15:12Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/fpu: Keep xfd_state in sync with MSR_IA32_XFD\n\nCommit 672365477ae8 (\"x86/fpu: Update XFD state where required\") and\ncommit 8bf26758ca96 (\"x86/fpu: Add XFD state to fpstate\") introduced a\nper CPU variable xfd_state to keep the MSR_IA32_XFD value cached, in\norder to avoid unnecessary writes to the MSR.\n\nOn CPU hotplug MSR_IA32_XFD is reset to the init_fpstate.xfd, which\nwipes out any stale state. But the per CPU cached xfd value is not\nreset, which brings them out of sync.\n\nAs a consequence a subsequent xfd_update_state() might fail to update\nthe MSR which in turn can result in XRSTOR raising a #NM in kernel\nspace, which crashes the kernel.\n\nTo fix this, introduce xfd_set_state() to write xfd_state together\nwith MSR_IA32_XFD, and use it in all places that set MSR_IA32_XFD.",
"id": "GHSA-r4ww-r2x2-fj39",
"modified": "2024-07-03T18:42:25Z",
"published": "2024-05-17T15:31:09Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-35801"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/10e4b5166df9ff7a2d5316138ca668b42d004422"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1acbca933313aa866e39996904c9aca4d435c4cd"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/21c7c00dae55cb0e3810d5f9506b58f68475d41d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/92b0f04e937665bde5768f3fcc622dcce44413d8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b61e3b7055ac6edee4be071c52f48c26472d2624"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}