CVE-2026-46290
x86/efi: Fix graceful fault handling after FPU softirq changes
Description
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(). ]
INFO
Published Date :
June 8, 2026, 5:16 p.m.
Last Modified :
July 23, 2026, 8:10 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the Linux kernel to the patched version.
- Reboot the system after applying the update.
- Verify graceful fault handling in EFI runtime.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-46290.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-46290 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-46290
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-46290 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-46290 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Translated by [email protected]
Jul. 23, 2026
Action Type Old Value New Value Added Translation Title: Linux, Description: En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta: x86/efi: Corrección del manejo elegante de fallos después de los cambios en softirq de FPU Desde el commit d02198550423 ('x86/fpu: Mejorar el rendimiento criptográfico haciendo que la FPU en modo kernel sea utilizable de forma fiable en softirqs'), 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 ejecución de EFI, haciendo que in_interrupt() devuelva verdadero en un contexto de tarea normal. El gestor elegante de fallos de página efi_crash_gracefully_on_page_fault() usa in_interrupt() para salir de los fallos en un contexto de interrupción real. Con SOFTIRQ_OFFSET ahora establecido, el gestor siempre sale, dejando los fallos de página del firmware EFI sin manejar. Esto escala a die() que también ve in_interrupt() como verdadero y llama a panic('Excepción fatal en interrupción'), resultando en una congelación dura del sistema. En sistemas con firmware defectuoso que dispara fallos de página durante las llamadas de tiempo de ejecución de EFI (p. ej., acceder a memoria no mapeada en GetTime()), esto causa un cuelgue irrecuperable en lugar de la recuperación elegante EFI_ABORTED esperada. Solución reemplazando in_interrupt() con !in_task(). Esto preserva la intención original de salir por interrupciones o fallos NMI, mientras ya no se dispara falsamente desde el local_bh_disable() de la ruta de código de la FPU. [ardb: Sashiko detectó que usar 'in_hardirq() || in_nmi()' deja una ventana donde un softirq puede ser tomado antes de que se llame a fpregs_lock(), pero después de que efi_rts_work.efi_rts_id haya sido asignado, y cualquier fallo de página que ocurra en esa ventana será entonces mal identificado como causado por el firmware. En su lugar, use !in_task(), que incorpora in_serving_softirq(). ] -
Initial Analysis by [email protected]
Jul. 08, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.7 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.15 up to (excluding) 6.18.30 Added Reference Type kernel.org: https://git.kernel.org/stable/c/088f65e206087bf903743bd18417261d7a4c9644 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/22b365ba1af3d8c6036b8e5112fffe80998b85a0 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/db155b86d1523e85941f61efd7d7ffb594cc9a29 Types: Patch -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'd02198550423a0b695e7a24ec77153209ad45b09', 'lessThan': '22b365ba1af3d8c6036b8e5112fffe80998b85a0', 'versionType': 'git'}, {'status': 'affected', 'version': 'd02198550423a0b695e7a24ec77153209ad45b09', 'lessThan': 'db155b86d1523e85941f61efd7d7ffb594cc9a29', 'versionType': 'git'}, {'status': 'affected', 'version': 'd02198550423a0b695e7a24ec77153209ad45b09', 'lessThan': '088f65e206087bf903743bd18417261d7a4c9644', 'versionType': 'git'}], 'programFiles': ['arch/x86/platform/efi/quirks.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.15'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.15', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.30', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.7', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['arch/x86/platform/efi/quirks.c'], 'defaultStatus': 'affected'}] -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 08, 2026
Action Type Old Value New Value Added Description 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(). ] Added Reference https://git.kernel.org/stable/c/088f65e206087bf903743bd18417261d7a4c9644 Added Reference https://git.kernel.org/stable/c/22b365ba1af3d8c6036b8e5112fffe80998b85a0 Added Reference https://git.kernel.org/stable/c/db155b86d1523e85941f61efd7d7ffb594cc9a29