FKIE_CVE-2026-46290
Vulnerability from fkie_nvd - Published: 2026-06-08 17:16 - Updated: 2026-07-23 08:10
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
x86/efi: Fix graceful fault handling after FPU softirq changes
Since commit d02198550423 ("x86/fpu: Improve crypto performance by
making kernel-mode FPU reliably usable in softirqs"), kernel_fpu_begin()
calls fpregs_lock() which uses local_bh_disable() instead of the
previous preempt_disable(). This sets SOFTIRQ_OFFSET in preempt_count
during the entire EFI runtime service call, causing in_interrupt() to
return true in normal task context.
The graceful page fault handler efi_crash_gracefully_on_page_fault()
uses in_interrupt() to bail out for faults in real interrupt context.
With SOFTIRQ_OFFSET now set, the handler always bails out, leaving EFI
firmware page faults unhandled. This escalates to die() which also sees
in_interrupt() as true and calls panic("Fatal exception in interrupt"),
resulting in a hard system freeze. On systems with buggy firmware that
triggers page faults during EFI runtime calls (e.g., accessing unmapped
memory in GetTime()), this causes an unrecoverable hang instead of the
expected graceful EFI_ABORTED recovery.
Fix by replacing in_interrupt() with !in_task(). This preserves the
original intent of bailing for interrupts or NMI faults, while no longer
falsely triggering from the FPU code path's local_bh_disable().
[ardb: Sashiko spotted that using 'in_hardirq() || in_nmi()' leaves a
window where a softirq may be taken before fpregs_lock() is
called, but after efi_rts_work.efi_rts_id has been assigned,
and any page faults occurring in that window will then be
misidentified as having been caused by the firmware. Instead,
use !in_task(), which incorporates in_serving_softirq(). ]
References
Impacted products
| Vendor | Product | Version | |
|---|---|---|---|
| linux | linux_kernel | * | |
| linux | linux_kernel | * | |
| linux | linux_kernel | 7.1 | |
| linux | linux_kernel | 7.1 |
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"arch/x86/platform/efi/quirks.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "22b365ba1af3d8c6036b8e5112fffe80998b85a0",
"status": "affected",
"version": "d02198550423a0b695e7a24ec77153209ad45b09",
"versionType": "git"
},
{
"lessThan": "db155b86d1523e85941f61efd7d7ffb594cc9a29",
"status": "affected",
"version": "d02198550423a0b695e7a24ec77153209ad45b09",
"versionType": "git"
},
{
"lessThan": "088f65e206087bf903743bd18417261d7a4c9644",
"status": "affected",
"version": "d02198550423a0b695e7a24ec77153209ad45b09",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"arch/x86/platform/efi/quirks.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.15"
},
{
"lessThan": "6.15",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.30",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"version": "7.0.7",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "7A99D29F-3622-4F26-9E29-80DF70FFF2B1",
"versionEndExcluding": "6.18.30",
"versionStartIncluding": "6.15",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "D0893CA7-9AE6-4DFE-AC75-48967D73AD8E",
"versionEndExcluding": "7.0.7",
"versionStartIncluding": "6.19",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*",
"matchCriteriaId": "B1EF7059-E670-45F4-B422-54C40FA86390",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*",
"matchCriteriaId": "0D38F0BF-A728-4133-A358-D44A2F7EE6D6",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/efi: Fix graceful fault handling after FPU softirq changes\n\nSince commit d02198550423 (\"x86/fpu: Improve crypto performance by\nmaking kernel-mode FPU reliably usable in softirqs\"), kernel_fpu_begin()\ncalls fpregs_lock() which uses local_bh_disable() instead of the\nprevious preempt_disable(). This sets SOFTIRQ_OFFSET in preempt_count\nduring the entire EFI runtime service call, causing in_interrupt() to\nreturn true in normal task context.\n\nThe graceful page fault handler efi_crash_gracefully_on_page_fault()\nuses in_interrupt() to bail out for faults in real interrupt context.\nWith SOFTIRQ_OFFSET now set, the handler always bails out, leaving EFI\nfirmware page faults unhandled. This escalates to die() which also sees\nin_interrupt() as true and calls panic(\"Fatal exception in interrupt\"),\nresulting in a hard system freeze. On systems with buggy firmware that\ntriggers page faults during EFI runtime calls (e.g., accessing unmapped\nmemory in GetTime()), this causes an unrecoverable hang instead of the\nexpected graceful EFI_ABORTED recovery.\n\nFix by replacing in_interrupt() with !in_task(). This preserves the\noriginal intent of bailing for interrupts or NMI faults, while no longer\nfalsely triggering from the FPU code path\u0027s local_bh_disable().\n\n[ardb: Sashiko spotted that using \u0027in_hardirq() || in_nmi()\u0027 leaves a\n window where a softirq may be taken before fpregs_lock() is\n called, but after efi_rts_work.efi_rts_id has been assigned,\n and any page faults occurring in that window will then be\n misidentified as having been caused by the firmware. Instead,\n use !in_task(), which incorporates in_serving_softirq(). ]"
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nx86/efi: Correcci\u00f3n del manejo elegante de fallos despu\u00e9s de los cambios en softirq de FPU\n\nDesde el commit d02198550423 (\u0027x86/fpu: Mejorar el rendimiento criptogr\u00e1fico haciendo que la FPU en modo kernel sea utilizable de forma fiable en softirqs\u0027), kernel_fpu_begin() llama a fpregs_lock() que usa local_bh_disable() en lugar del preempt_disable() anterior. Esto establece SOFTIRQ_OFFSET en preempt_count durante toda la llamada al servicio de tiempo de ejecuci\u00f3n de EFI, haciendo que in_interrupt() devuelva verdadero en un contexto de tarea normal.\n\nEl gestor elegante de fallos de p\u00e1gina efi_crash_gracefully_on_page_fault() usa in_interrupt() para salir de los fallos en un contexto de interrupci\u00f3n real. Con SOFTIRQ_OFFSET ahora establecido, el gestor siempre sale, dejando los fallos de p\u00e1gina del firmware EFI sin manejar. Esto escala a die() que tambi\u00e9n ve in_interrupt() como verdadero y llama a panic(\u0027Excepci\u00f3n fatal en interrupci\u00f3n\u0027), resultando en una congelaci\u00f3n dura del sistema. En sistemas con firmware defectuoso que dispara fallos de p\u00e1gina durante las llamadas de tiempo de ejecuci\u00f3n de EFI (p. ej., acceder a memoria no mapeada en GetTime()), esto causa un cuelgue irrecuperable en lugar de la recuperaci\u00f3n elegante EFI_ABORTED esperada.\n\nSoluci\u00f3n reemplazando in_interrupt() con !in_task(). Esto preserva la intenci\u00f3n original de salir por interrupciones o fallos NMI, mientras ya no se dispara falsamente desde el local_bh_disable() de la ruta de c\u00f3digo de la FPU.\n\n[ardb: Sashiko detect\u00f3 que usar \u0027in_hardirq() || in_nmi()\u0027 deja una ventana donde un softirq puede ser tomado antes de que se llame a fpregs_lock(), pero despu\u00e9s de que efi_rts_work.efi_rts_id haya sido asignado, y cualquier fallo de p\u00e1gina que ocurra en esa ventana ser\u00e1 entonces mal identificado como causado por el firmware. En su lugar, use !in_task(), que incorpora in_serving_softirq(). ]"
}
],
"id": "CVE-2026-46290",
"lastModified": "2026-07-23T08:10:00.137",
"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": "2026-06-08T17:16:47.230",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/088f65e206087bf903743bd18417261d7a4c9644"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/22b365ba1af3d8c6036b8e5112fffe80998b85a0"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/db155b86d1523e85941f61efd7d7ffb594cc9a29"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "NVD-CWE-noinfo"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
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