High · CVSS 7.8CVE-2025-68171

x86/fpu: Ensure XFD state on signal deliveryCVE-2025-68171

Answer in brief

CVE-2025-68171 records a High severity (CVSS 7.8) vulnerability in x86/fpu: Ensure XFD state on signal delivery. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Dec 16, 2025Updated Oct 15, 2026Source checked Oct 15, 2026First seen by HOL Oct 15, 2026Material review Oct 15, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.8
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=672365477ae8afca5a1cca98c1deb733235e4525 <eefbfb722042fc9210d2e0ac2b063fd1abf51895 \|\| >=672365477ae8afca5a1cca98c1deb733235e4525 <1811c610653c0cd21cc9add14595b7cffaeca511 \|\| >=672365477ae8afca5a1cca98c1deb733235e4525 <5b2619b488f1d08b960c43c6468dd0759e8b3035 \|\| >=672365477ae8afca5a1cca98c1deb733235e4525 <3f735419c4b43cde42e6d408db39137b82474e31 \|\| >=672365477ae8afca5a1cca98c1deb733235e4525 <388eff894d6bc5f921e9bfff0e4b0ab2684a96e9	eefbfb722042fc9210d2e0ac2b063fd1abf51895, 1811c610653c0cd21cc9add14595b7cffaeca511, 5b2619b488f1d08b960c43c6468dd0759e8b3035, 3f735419c4b43cde42e6d408db39137b82474e31, 388eff894d6bc5f921e9bfff0e4b0ab2684a96e9
Linux/Linuxgeneric	5.16	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to eefbfb722042fc9210d2e0ac2b063fd1abf51895 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Dec 16, 2025
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 15, 2026

Sources and claim methodology

Upstream source description

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 ]

Quoted source text, attributed separately from HOL analysis.