CVE-2025-38689

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2025-38689", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:24.032Z", "datePublished": "2025-09-04T15:32:43.530Z", "dateUpdated": "2026-05-11T21:33:04.964Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T21:33:04.964Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/fpu: Fix NULL dereference in avx512_status()\n\nProblem\n-------\nWith CONFIG_X86_DEBUG_FPU enabled, reading /proc/[kthread]/arch_status\ncauses a warning and a NULL pointer dereference.\n\nThis is because the AVX-512 timestamp code uses x86_task_fpu() but\ndoesn't check it for NULL. CONFIG_X86_DEBUG_FPU addles that function\nfor kernel threads (PF_KTHREAD specifically), making it return NULL.\n\nThe point of the warning was to ensure that kernel threads only access\ntask->fpu after going through kernel_fpu_begin()/_end(). Note: all\nkernel tasks exposed in /proc have a valid task->fpu.\n\nSolution\n--------\nOne option is to silence the warning and check for NULL from\nx86_task_fpu(). However, that warning is fairly fresh and seems like a\ndefense against misuse of the FPU state in kernel threads.\n\nInstead, stop outputting AVX-512_elapsed_ms for kernel threads\naltogether. The data was garbage anyway because avx512_timestamp is\nonly updated for user threads, not kernel threads.\n\nIf anyone ever wants to track kernel thread AVX-512 use, they can come\nback later and do it properly, separate from this bug fix.\n\n[ dhansen: mostly rewrite changelog ]"}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kernel/fpu/xstate.c"], "versions": [{"version": "22aafe3bcb67472effdea1ccf0df20280192bbaf", "lessThan": "2ca887e81095b99d890a8878841f36f4920181e6", "status": "affected", "versionType": "git"}, {"version": "22aafe3bcb67472effdea1ccf0df20280192bbaf", "lessThan": "31cd31c9e17ece125aad27259501a2af69ccb020", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["arch/x86/kernel/fpu/xstate.c"], "versions": [{"version": "6.16", "status": "affected"}, {"version": "0", "lessThan": "6.16", "status": "unaffected", "versionType": "semver"}, {"version": "6.16.2", "lessThanOrEqual": "6.16.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.17", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "6.16.2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "6.17"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/2ca887e81095b99d890a8878841f36f4920181e6"}, {"url": "https://git.kernel.org/stable/c/31cd31c9e17ece125aad27259501a2af69ccb020"}], "title": "x86/fpu: Fix NULL dereference in avx512_status()", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["arch/x86/kernel/fpu/xstate.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "2ca887e81095b99d890a8878841f36f4920181e6", "status": "affected", "version": "22aafe3bcb67472effdea1ccf0df20280192bbaf", "versionType": "git"}, {"lessThan": "31cd31c9e17ece125aad27259501a2af69ccb020", "status": "affected", "version": "22aafe3bcb67472effdea1ccf0df20280192bbaf", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["arch/x86/kernel/fpu/xstate.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.16"}, {"lessThan": "6.16", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.16.*", "status": "unaffected", "version": "6.16.2", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "6.17", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "BD7C087D-2415-4521-B624-30003352F899", "versionEndExcluding": "6.16.2", "versionStartIncluding": "6.16", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:*", "matchCriteriaId": "327D22EF-390B-454C-BD31-2ED23C998A1C", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/fpu: Fix NULL dereference in avx512_status()\n\nProblem\n-------\nWith CONFIG_X86_DEBUG_FPU enabled, reading /proc/[kthread]/arch_status\ncauses a warning and a NULL pointer dereference.\n\nThis is because the AVX-512 timestamp code uses x86_task_fpu() but\ndoesn't check it for NULL. CONFIG_X86_DEBUG_FPU addles that function\nfor kernel threads (PF_KTHREAD specifically), making it return NULL.\n\nThe point of the warning was to ensure that kernel threads only access\ntask->fpu after going through kernel_fpu_begin()/_end(). Note: all\nkernel tasks exposed in /proc have a valid task->fpu.\n\nSolution\n--------\nOne option is to silence the warning and check for NULL from\nx86_task_fpu(). However, that warning is fairly fresh and seems like a\ndefense against misuse of the FPU state in kernel threads.\n\nInstead, stop outputting AVX-512_elapsed_ms for kernel threads\naltogether. The data was garbage anyway because avx512_timestamp is\nonly updated for user threads, not kernel threads.\n\nIf anyone ever wants to track kernel thread AVX-512 use, they can come\nback later and do it properly, separate from this bug fix.\n\n[ dhansen: mostly rewrite changelog ]"}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nx86/fpu: Corrige la desreferencia de NULL en avx512_status()\n\nProblema\n-------\nCon CONFIG_X86_DEBUG_FPU habilitado, la lectura de /proc/[kthread]/arch_status causa una advertencia y una desreferencia de puntero NULL.\n\nEsto se debe a que el c\u00f3digo de marca de tiempo AVX-512 usa x86_task_fpu() pero no lo verifica en busca de NULL. CONFIG_X86_DEBUG_FPU confunde esa funci\u00f3n para los hilos del kernel (espec\u00edficamente PF_KTHREAD), haciendo que devuelva NULL.\n\nEl prop\u00f3sito de la advertencia era asegurar que los hilos del kernel solo accedieran a task->fpu despu\u00e9s de pasar por kernel_fpu_begin()/_end(). Nota: todas las tareas del kernel expuestas en /proc tienen un task->fpu v\u00e1lido.\n\nSoluci\u00f3n\n--------\nUna opci\u00f3n es silenciar la advertencia y verificar si hay NULL desde x86_task_fpu(). Sin embargo, esa advertencia es bastante reciente y parece una defensa contra el uso indebido del estado de la FPU en los hilos del kernel.\n\nEn su lugar, se deja de emitir AVX-512_elapsed_ms para los hilos del kernel por completo. Los datos eran basura de todos modos porque avx512_timestamp solo se actualiza para los hilos de usuario, no para los hilos del kernel.\n\nSi alguien alguna vez quiere rastrear el uso de AVX-512 en hilos del kernel, puede volver m\u00e1s tarde y hacerlo correctamente, por separado de esta correcci\u00f3n de errores.\n\n[ dhansen: reescritura mayoritaria del registro de cambios ]"}], "id": "CVE-2025-38689", "lastModified": "2026-10-19T21:10:00.160", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2025-09-04T16:15:37.013", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/2ca887e81095b99d890a8878841f36f4920181e6"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/31cd31c9e17ece125aad27259501a2af69ccb020"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-476"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: x86/fpu: Fix NULL dereference in avx512_status()", "id": "2393174", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2393174"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "details": ["No description is available for this CVE."], "name": "CVE-2025-38689", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-09-04T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2025-38689\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-38689\nhttps://lore.kernel.org/linux-cve-announce/2025090448-CVE-2025-38689-ac95@gregkh/T"], "threat_severity": "Moderate"}

{"created": "2025-09-05T14:02:39.482058+00:00", "updated": "2025-09-05T14:02:39.482129+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}