CVE-2021-47577

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But it's possible to have\na race between the two, where creation checks exit finding it not set,\nbut we're in the process of exiting. The exit side will cancel pending\ncreation task_work, but there's a gap where we add task_work after we've\ncanceled existing creations at exit time.\n\nFix this by checking the EXIT bit post adding the creation task_work.\nIf it's set, run the same cancelation that exit does."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.15.11", "versionStartIncluding": "5.13"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "5.16", "versionStartIncluding": "5.13"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:48:27.449Z"}}}, "cveMetadata": {"cveId": "CVE-2021-47577", "state": "PUBLISHED", "dateUpdated": "2026-08-05T08:48:27.449Z", "dateReserved": "2024-05-24T15:11:00.730Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2024-06-19T14:53:45.393Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

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But it's possible to have\na race between the two, where creation checks exit finding it not set,\nbut we're in the process of exiting. The exit side will cancel pending\ncreation task_work, but there's a gap where we add task_work after we've\ncanceled existing creations at exit time.\n\nFix this by checking the EXIT bit post adding the creation task_work.\nIf it's set, run the same cancelation that exit does."}, {"lang": "es", "value": "En el kernel de Linux se ha resuelto la siguiente vulnerabilidad: io-wq: comprueba la salida de wq despu\u00e9s de agregar un nuevo trabajador task_work Comprobamos IO_WQ_BIT_EXIT antes de intentar crear un nuevo trabajador, y wq exit cancela el trabajo pendiente si tenemos alguno. Pero es posible tener una carrera entre los dos, donde las comprobaciones de creaci\u00f3n salen y descubren que no est\u00e1 configurado, pero estamos en el proceso de salir. El lado de salida cancelar\u00e1 la creaci\u00f3n pendiente task_work, pero hay un espacio en el que agregamos task_work despu\u00e9s de haber cancelado las creaciones existentes en el momento de la salida. Solucione este problema marcando la publicaci\u00f3n del bit EXIT agregando la tarea de creaci\u00f3n_trabajo. Si est\u00e1 configurado, ejecute la misma cancelaci\u00f3n que realiza la salida."}], "id": "CVE-2021-47577", "lastModified": "2026-08-04T10:17:09.370", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}, {"cvssData": {"attackComplexity": "HIGH", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 4.7, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.0, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2021-47577", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2024-06-21T14:05:50.192086Z", "version": "2.0.3"}}]}, "published": "2024-06-19T15:15:52.223", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/4b4e5bbf9386d4ec21d91c0cb0fd60b9bba778ec"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/71a85387546e50b1a37b0fa45dadcae3bfb35cf6"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/4b4e5bbf9386d4ec21d91c0cb0fd60b9bba778ec"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/71a85387546e50b1a37b0fa45dadcae3bfb35cf6"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-362"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: io-wq: check for wq exit after adding new worker task_work", "id": "2293252", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2293252"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.7", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-362", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nio-wq: check for wq exit after adding new worker task_work\nWe check IO_WQ_BIT_EXIT before attempting to create a new worker, and\nwq exit cancels pending work if we have any. But it's possible to have\na race between the two, where creation checks exit finding it not set,\nbut we're in the process of exiting. The exit side will cancel pending\ncreation task_work, but there's a gap where we add task_work after we've\ncanceled existing creations at exit time.\nFix this by checking the EXIT bit post adding the creation task_work.\nIf it's set, run the same cancelation that exit does."], "mitigation": {"lang": "en:us", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability."}, "name": "CVE-2021-47577", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2024-06-19T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2021-47577\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-47577\nhttps://lore.kernel.org/linux-cve-announce/2024061915-CVE-2021-47577-c4c7@gregkh/T"], "statement": "Red Hat Enterprise Linux is not impacted by this CVE, as the vulnerability in question does not affect the specific versions or configurations of the Linux kernel used in its distributions. This ensures that users of Red Hat Enterprise Linux are not exposed to the potential risks associated with this issue, and no further action or mitigation is necessary for systems running this operating system.", "threat_severity": "Moderate"}

{"created": "2025-07-13T21:07:12.246053+00:00", "updated": "2025-07-13T21:07:12.246122+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}