CVE-2021-47533

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Since\ndrm_crtc_commit_put can free the drm_crtc_commit structure directly if\nwe were the last user, this means that it can lead to a use-after free\nif we were to duplicate the state, and that stale pointer would even be\ncopied to the new state.\n\nSet the pointer to NULL once we're done with the wait so that we don't\ncarry over a pointer to a free'd structure."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: drm/vc4: kms: borre el puntero de commit FIFO de HVS una vez realizado. El commit 9ec03d7f1ed3 (\"drm/vc4: kms: espere a los usuarios FIFO anteriores antes de una confirmaci\u00f3n\") introdujo una espera en el commit anterior realizada en un HVS FIFO determinado. Sin embargo, nunca borramos ese puntero una vez hecho. Dado que drm_crtc_commit_put puede liberar la estructura drm_crtc_commit directamente si fu\u00e9ramos el \u00faltimo usuario, esto significa que puede llevar a un use-after free si duplic\u00e1ramos el estado, y ese puntero obsoleto incluso se copiar\u00eda al nuevo estado. Establezca el puntero en NULL una vez que hayamos terminado con la espera para que no transfiramos un puntero a una estructura liberada."}], "id": "CVE-2021-47533", "lastModified": "2026-08-04T10:17:07.453", "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": "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": "nvd@nist.gov", "type": "Primary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2021-47533", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2024-05-24T19:17:49.041066Z", "version": "2.0.3"}}]}, "published": "2024-05-24T15:15:16.773", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/2931db9a5ed219546cf2ae0546698faf78281b89"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/d134c5ff71c7f2320fc7997f2fbbdedf0c76889a"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/2931db9a5ed219546cf2ae0546698faf78281b89"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/d134c5ff71c7f2320fc7997f2fbbdedf0c76889a"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Modified", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: drm/vc4: kms: Clear the HVS FIFO commit pointer once done", "id": "2283418", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2283418"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L", "status": "draft"}, "cwe": "CWE-416", "details": ["In the Linux kernel, the following vulnerability has been resolved:\ndrm/vc4: kms: Clear the HVS FIFO commit pointer once done\nCommit 9ec03d7f1ed3 (\"drm/vc4: kms: Wait on previous FIFO users before a\ncommit\") introduced a wait on the previous commit done on a given HVS\nFIFO.\nHowever, we never cleared that pointer once done. Since\ndrm_crtc_commit_put can free the drm_crtc_commit structure directly if\nwe were the last user, this means that it can lead to a use-after free\nif we were to duplicate the state, and that stale pointer would even be\ncopied to the new state.\nSet the pointer to NULL once we're done with the wait so that we don't\ncarry over a pointer to a free'd structure."], "name": "CVE-2021-47533", "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": "2024-05-24T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2021-47533\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-47533\nhttps://lore.kernel.org/linux-cve-announce/2024052436-CVE-2021-47533-a03a@gregkh/T"], "threat_severity": "Low"}

{"created": "2025-07-13T11:14:48.504028+00:00", "updated": "2025-07-13T11:14:48.504087+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}