CVE-2025-68171 (GCVE-0-2025-68171)
Vulnerability from cvelistv5
Published
2025-12-16 13:42
Modified
2025-12-16 13:42
Severity ?
VLAI Severity ?
EPSS score ?
Summary
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:
<TASK>
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 ]
References
Impacted products
{
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"dateUpdated": "2025-12-16T13:42:51.121Z",
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"url": "https://git.kernel.org/stable/c/5b2619b488f1d08b960c43c6468dd0759e8b3035"
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},
{
"url": "https://git.kernel.org/stable/c/388eff894d6bc5f921e9bfff0e4b0ab2684a96e9"
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],
"title": "x86/fpu: Ensure XFD state on signal delivery",
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"cveId": "CVE-2025-68171",
"datePublished": "2025-12-16T13:42:51.121Z",
"dateReserved": "2025-12-16T13:41:40.251Z",
"dateUpdated": "2025-12-16T13:42:51.121Z",
"state": "PUBLISHED"
},
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}
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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