CVE-2026-43331

{"id": "CVE-2026-43331", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "affected": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "affectedData": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "0d345996e4cb573f8cc81d49b3ee9a7fd2035bef", "lessThan": "0e96cd314c0d819c1635d68125a4d77852c2162e", "versionType": "git"}, {"status": "affected", "version": "0d345996e4cb573f8cc81d49b3ee9a7fd2035bef", "lessThan": "593d67032544b9271094fc9b43e437e017cb2b2f", "versionType": "git"}, {"status": "affected", "version": "0d345996e4cb573f8cc81d49b3ee9a7fd2035bef", "lessThan": "1e3e98596c2769721ade0418434852fb3af4849a", "versionType": "git"}, {"status": "affected", "version": "0d345996e4cb573f8cc81d49b3ee9a7fd2035bef", "lessThan": "de05c66fab8847237a9ca216934e56d3ee837f08", "versionType": "git"}, {"status": "affected", "version": "0d345996e4cb573f8cc81d49b3ee9a7fd2035bef", "lessThan": "917e3ad3321e75ca0223d5ccf26ceda116aa51e1", "versionType": "git"}], "programFiles": ["arch/x86/kernel/Makefile", "arch/x86/mm/Makefile"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "6.6"}, {"status": "unaffected", "version": "0", "lessThan": "6.6", "versionType": "semver"}, {"status": "unaffected", "version": "6.6.143", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.93", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.22", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "6.19.12", "versionType": "semver", "lessThanOrEqual": "6.19.*"}, {"status": "unaffected", "version": "7.0", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["arch/x86/kernel/Makefile", "arch/x86/mm/Makefile"], "defaultStatus": "affected"}]}], "published": "2026-05-08T14:16:42.763", "references": [{"url": "https://git.kernel.org/stable/c/0e96cd314c0d819c1635d68125a4d77852c2162e", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/1e3e98596c2769721ade0418434852fb3af4849a", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/593d67032544b9271094fc9b43e437e017cb2b2f", "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/917e3ad3321e75ca0223d5ccf26ceda116aa51e1", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}, {"url": "https://git.kernel.org/stable/c/de05c66fab8847237a9ca216934e56d3ee837f08", "tags": ["Patch"], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "NVD-CWE-noinfo"}]}], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/kexec: Disable KCOV instrumentation after load_segments()\n\nThe load_segments() function changes segment registers, invalidating GS base\n(which KCOV relies on for per-cpu data). When CONFIG_KCOV is enabled, any\nsubsequent instrumented C code call (e.g. native_gdt_invalidate()) begins\ncrashing the kernel in an endless loop.\n\nTo reproduce the problem, it's sufficient to do kexec on a KCOV-instrumented\nkernel:\n\n $ kexec -l /boot/otherKernel\n $ kexec -e\n\nThe real-world context for this problem is enabling crash dump collection in\nsyzkaller. For this, the tool loads a panic kernel before fuzzing and then\ncalls makedumpfile after the panic. This workflow requires both CONFIG_KEXEC\nand CONFIG_KCOV to be enabled simultaneously.\n\nAdding safeguards directly to the KCOV fast-path (__sanitizer_cov_trace_pc())\nis also undesirable as it would introduce an extra performance overhead.\n\nDisabling instrumentation for the individual functions would be too fragile,\nso disable KCOV instrumentation for the entire machine_kexec_64.c and\nphysaddr.c. If coverage-guided fuzzing ever needs these components in the\nfuture, other approaches should be considered.\n\nThe problem is not relevant for 32 bit kernels as CONFIG_KCOV is not supported\nthere.\n\n [ bp: Space out comment for better readability. ]"}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nx86/kexec: Deshabilitar la instrumentaci\u00f3n KCOV despu\u00e9s de load_segments()\n\nLa funci\u00f3n load_segments() cambia los registros de segmento, invalidando la base GS (en la que KCOV se basa para los datos por CPU). Cuando CONFIG_KCOV est\u00e1 habilitado, cualquier llamada posterior a c\u00f3digo C instrumentado (por ejemplo, native_gdt_invalidate()) comienza a bloquear el kernel en un bucle infinito.\n\nPara reproducir el problema, es suficiente con hacer kexec en un kernel instrumentado con KCOV:\n\n $ kexec -l /boot/otherKernel\n $ kexec -e\n\nEl contexto real de este problema es la habilitaci\u00f3n de la recolecci\u00f3n de volcados de fallos en syzkaller. Para esto, la herramienta carga un kernel de p\u00e1nico antes del fuzzing y luego llama a makedumpfile despu\u00e9s del p\u00e1nico. Este flujo de trabajo requiere que tanto CONFIG_KEXEC como CONFIG_KCOV est\u00e9n habilitados simult\u00e1neamente.\n\nA\u00f1adir salvaguardas directamente a la ruta r\u00e1pida de KCOV (__sanitizer_cov_trace_pc()) tambi\u00e9n es indeseable ya que introducir\u00eda una sobrecarga de rendimiento adicional.\n\nDeshabilitar la instrumentaci\u00f3n para las funciones individuales ser\u00eda demasiado fr\u00e1gil, as\u00ed que se deshabilita la instrumentaci\u00f3n KCOV para todo machine_kexec_64.c y physaddr.c. Si el fuzzing guiado por cobertura alguna vez necesita estos componentes en el futuro, se deber\u00edan considerar otros enfoques.\n\nEl problema no es relevante para kernels de 32 bits ya que CONFIG_KCOV no es compatible all\u00ed.\n\n [ bp: Espaciar el comentario para una mejor legibilidad. ]"}], "lastModified": "2026-11-11T20:10:00.273", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "CB33D19D-30CB-4E4C-9018-2230BD327607", "versionEndExcluding": "6.18.22", "versionStartIncluding": "6.6"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0A2B9540-02D5-41B4-B16A-82AF66FD4F36", "versionEndExcluding": "6.19.12", "versionStartIncluding": "6.19"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"}], "operator": "OR"}]}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}