x86/fpu: Ensure XFD state on signal delivery
In the Linux kernel, the following vulnerability has been resolved: x86/fpu: Ensure XFD state on signal delivery Sean reported [1] the following splat when running KVM tests: WARNING: CPU: 232 PID: 15391 at xfd_validate_state+0x65/0x70 Call Trace: fpu__clear_user_states+0x9c/0x100 arch_do_signal_or_restart+0x142/0x210 exit_to_user_mode_loop+0x55/0x100 do_syscall_64+0x205/0x2c0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 Chao further identified [2] a reproducible scenario involving signal delivery: a non-AMX task is preempted by an AMX-enabled task which modifies the XFD MSR. When the non-AMX task resumes and reloads XSTATE with init values, a warning is triggered due to a mismatch between fpstate::xfd and the CPU's current XFD state. fpu__clear_user_states() does not currently re-synchronize the XFD state after such preemption. Invoke xfd_update_state() which detects and corrects the mismatch if there is a dynamic feature. This also benefits the sigreturn path, as fpu__restore_sig() may call fpu__clear_user_states() when the sigframe is inaccessible. [ dhansen: minor changelog munging ]
CVE-2025-68171
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2025-68171
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "672365477ae8afca5a1cca98c1deb733235e4525",
"lessThan": "eefbfb722042fc9210d2e0ac2b063fd1abf51895",
"versionType": "git"
},
{
"status": "affected",
"version": "672365477ae8afca5a1cca98c1deb733235e4525",
"lessThan": "1811c610653c0cd21cc9add14595b7cffaeca511",
"versionType": "git"
},
{
"status": "affected",
"version": "672365477ae8afca5a1cca98c1deb733235e4525",
"lessThan": "5b2619b488f1d08b960c43c6468dd0759e8b3035",
"versionType": "git"
},
{
"status": "affected",
"version": "672365477ae8afca5a1cca98c1deb733235e4525",
"lessThan": "3f735419c4b43cde42e6d408db39137b82474e31",
"versionType": "git"
},
{
"status": "affected",
"version": "672365477ae8afca5a1cca98c1deb733235e4525",
"lessThan": "388eff894d6bc5f921e9bfff0e4b0ab2684a96e9",
"versionType": "git"
}
],
"programFiles": [
"arch/x86/kernel/fpu/core.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.159",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.117",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.58",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.17.8",
"versionType": "semver",
"lessThanOrEqual": "6.17.*"
},
{
"status": "unaffected",
"version": "6.18",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"arch/x86/kernel/fpu/core.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2025-68171
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #30723 · Revision 1
- Added to Heist Feed
- Publisher date