{"id":"CVE-2025-68171","revision":"1c520c32def044be8bb87b5ae2d3a8d7","records":[{"revision":"1c520c32def044be8bb87b5ae2d3a8d7","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2025-68171","aliases":[],"title":"x86/fpu: Ensure XFD state on signal delivery","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/fpu: Ensure XFD state on signal delivery\n\nSean reported [1] the following splat when running KVM tests:\n\n   WARNING: CPU: 232 PID: 15391 at xfd_validate_state+0x65/0x70\n   Call Trace:\n    <TASK>\n    fpu__clear_user_states+0x9c/0x100\n    arch_do_signal_or_restart+0x142/0x210\n    exit_to_user_mode_loop+0x55/0x100\n    do_syscall_64+0x205/0x2c0\n    entry_SYSCALL_64_after_hwframe+0x4b/0x53\n\nChao further identified [2] a reproducible scenario involving signal\ndelivery: a non-AMX task is preempted by an AMX-enabled task which\nmodifies the XFD MSR.\n\nWhen the non-AMX task resumes and reloads XSTATE with init values,\na warning is triggered due to a mismatch between fpstate::xfd and the\nCPU's current XFD state. fpu__clear_user_states() does not currently\nre-synchronize the XFD state after such preemption.\n\nInvoke xfd_update_state() which detects and corrects the mismatch if\nthere is a dynamic feature.\n\nThis also benefits the sigreturn path, as fpu__restore_sig() may call\nfpu__clear_user_states() when the sigframe is inaccessible.\n\n[ dhansen: minor changelog munging ]","state":0,"publishedAt":"2025-12-16T13:42:51.121+00:00","modifiedAt":"2026-10-15T22:02:46.869+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/x86/kernel/fpu/core.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"672365477ae8afca5a1cca98c1deb733235e4525\",\n                            \"lessThan\": \"eefbfb722042fc9210d2e0ac2b063fd1abf51895\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"672365477ae8afca5a1cca98c1deb733235e4525\",\n                            \"lessThan\": \"1811c610653c0cd21cc9add14595b7cffaeca511\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"672365477ae8afca5a1cca98c1deb733235e4525\",\n                            \"lessThan\": \"5b2619b488f1d08b960c43c6468dd0759e8b3035\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"672365477ae8afca5a1cca98c1deb733235e4525\",\n                            \"lessThan\": \"3f735419c4b43cde42e6d408db39137b82474e31\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"672365477ae8afca5a1cca98c1deb733235e4525\",\n                            \"lessThan\": \"388eff894d6bc5f921e9bfff0e4b0ab2684a96e9\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/x86/kernel/fpu/core.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"5.16\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"5.16\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.159\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.117\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.58\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.17.8\",\n                            \"lessThanOrEqual\": \"6.17.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/eefbfb722042fc9210d2e0ac2b063fd1abf51895","https://git.kernel.org/stable/c/1811c610653c0cd21cc9add14595b7cffaeca511","https://git.kernel.org/stable/c/5b2619b488f1d08b960c43c6468dd0759e8b3035","https://git.kernel.org/stable/c/3f735419c4b43cde42e6d408db39137b82474e31","https://git.kernel.org/stable/c/388eff894d6bc5f921e9bfff0e4b0ab2684a96e9"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-68171","license":"CVE Program Terms of Use","key":"cve-program:CVE-2025-68171","identifiers":["CVE-2025-68171"]},"retained":false,"historicalAffected":[]}],"coverage":[]}