📄 Description (English)
In the Linux kernel, the following vulnerability has been resolved:
ALSA: ctxfi: Fix missing SPDIFI1 index handling
SPDIF1 DAIO type isn't properly handled in daio_device_index() for
hw20k2, and it returned -EINVAL, which ended up with the out-of-bounds
array access. Follow the hw20k1 pattern and return the proper index
for this type, too.
🤖 AI Executive Summary
CVE-2026-31776 is a Linux kernel vulnerability in the ALSA ctxfi audio driver affecting hw20k2 hardware. The vulnerability stems from improper handling of SPDIF1 DAIO type in the daio_device_index() function, causing out-of-bounds array access when SPDIF1 is accessed. While the CVSS score is 7.8 (high), the practical impact is limited to systems with specific Creative Sound Blaster audio hardware running vulnerable kernel versions.
📄 Description (Arabic)
🤖 AI Intelligence Analysis Analyzed: May 7, 2026 07:32
🇸🇦 Saudi Arabia Impact Assessment
Impact on Saudi organizations is minimal as this vulnerability is specific to Creative Sound Blaster audio hardware (hw20k2) which is rarely deployed in critical Saudi infrastructure. Government agencies (NCA), banking institutions (SAMA-regulated), healthcare facilities, and energy sector (ARAMCO) typically do not rely on this consumer-grade audio hardware. The vulnerability would primarily affect individual workstations or non-critical systems with this specific audio card. Telecom operators (STC, Mobily) and data centers are unlikely to be impacted.
🏢 Affected Saudi Sectors
Workstations and Non-Critical Systems
Consumer Electronics
Audio/Media Production (Limited)
🎯 MITRE ATT&CK Techniques
⚖️ Saudi Risk Score (AI)
3.2
/ 10.0
🔧 Remediation Steps (English)
Immediate Actions:
1. Identify systems with Creative Sound Blaster hw20k2 audio hardware using: lspci | grep -i creative or checking /proc/asound/cards
2. Assess if SPDIF1 output is actively used in your environment
3. If SPDIF1 is not required, disable the audio device in BIOS or via kernel module blacklisting
Patching Guidance:
1. Update Linux kernel to version 7.0 final release or later when available
2. For interim versions, apply the upstream patch from Linux kernel repository that adds proper SPDIF1 index handling in daio_device_index() function
3. Verify patch application by checking kernel source: sound/pci/ctxfi/cthw20k2.c
Compensating Controls:
1. Disable ctxfi kernel module if not required: echo 'blacklist snd_ctxfi' >> /etc/modprobe.d/blacklist.conf
2. Restrict access to /dev/snd/* devices via file permissions and AppArmor/SELinux policies
3. Monitor kernel logs for audio subsystem errors: journalctl -u kernel | grep -i ctxfi
Detection Rules:
1. Monitor for kernel panic/oops messages containing 'ctxfi' or 'daio_device_index'
2. Alert on failed audio device initialization attempts
3. Track access attempts to SPDIF1 output on affected systems
🔧 خطوات المعالجة (العربية)
الإجراءات الفورية:
1. تحديد الأنظمة التي تحتوي على أجهزة صوت Creative Sound Blaster hw20k2 باستخدام: lspci | grep -i creative أو التحقق من /proc/asound/cards
2. تقييم ما إذا كان مخرج SPDIF1 قيد الاستخدام النشط في بيئتك
3. إذا لم يكن SPDIF1 مطلوباً، قم بتعطيل جهاز الصوت في BIOS أو عبر إدراج وحدة النواة في القائمة السوداء
إرشادات التصحيح:
1. تحديث نواة Linux إلى الإصدار 7.0 النهائي أو إصدار أحدث عند توفره
2. للإصدارات المؤقتة، طبق الرقعة من مستودع نواة Linux التي تضيف معالجة فهرس SPDIF1 الصحيحة في دالة daio_device_index()
3. تحقق من تطبيق الرقعة بفحص مصدر النواة: sound/pci/ctxfi/cthw20k2.c
الضوابط التعويضية:
1. تعطيل وحدة نواة ctxfi إذا لم تكن مطلوبة: echo 'blacklist snd_ctxfi' >> /etc/modprobe.d/blacklist.conf
2. تقييد الوصول إلى أجهزة /dev/snd/* عبر أذونات الملفات وسياسات AppArmor/SELinux
3. مراقبة سجلات النواة لأخطاء النظام الفرعي للصوت: journalctl -u kernel | grep -i ctxfi
قواعد الكشف:
1. مراقبة رسائل kernel panic/oops التي تحتوي على 'ctxfi' أو 'daio_device_index'
2. تنبيه محاولات تهيئة جهاز صوت فاشلة
3. تتبع محاولات الوصول إلى مخرج SPDIF1 على الأنظمة المتأثرة
📋 Regulatory Compliance Mapping
🟢 NCA ECC 2024
ECC 2024 A.12.6.1 - Management of technical vulnerabilities
ECC 2024 A.14.2.1 - Secure development policy
ECC 2024 A.12.2.1 - Monitoring and logging
🔵 SAMA CSF
ID.RA-1 - Asset management and vulnerability identification
PR.IP-12 - System and information integrity
DE.CM-3 - Monitoring and detection of anomalies
🟡 ISO 27001:2022
A.12.6.1 - Management of technical vulnerabilities
A.14.2.1 - Secure development policy and procedures
A.12.4.1 - Event logging
📦 Affected Products / CPE 7 entries
linux:linux_kernel
linux:linux_kernel:7.0
linux:linux_kernel:7.0
linux:linux_kernel:7.0
linux:linux_kernel:7.0
linux:linux_kernel:7.0
linux:linux_kernel:7.0