CVE-2026-89501

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89501", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.715Z", "datePublished": "2026-09-11T19:43:50.063Z", "dateUpdated": "2026-10-19T08:47:52.839Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:47:52.839Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Hold cpu_buffer::lock when resizing a subbuf\n\nBecause, ring_buffer_subbuf_order_set() can clear cpu_buffer->free_page,\nhold cpu_buffer->lock to prevent races with\nring_buffer_alloc_read_page() and ring_buffer_free_read_page()."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH"}, "scenarios": [{"lang": "en", "value": "AV:L - The bug is reached only via local tracefs syscalls: write() to buffer_subbuf_size_kb (ring_buffer_subbuf_order_set) racing with read()/close() on per_cpu/*/trace_pipe_raw (ring_buffer_alloc_read_page and ring_buffer_free_read_page). No network, adjacent-radio, or physical path reaches this free_page steal.\nAC:L - The attacker controls both sides of the race: one thread toggles buffer_subbuf_size_kb to copy and NULL cpu_buffer->free_page without cpu_buffer->lock, while another reads or closes trace_pipe_raw, which takes or caches that page under the lock. Success does not depend on an uninfluenced victim state.\nPR:L - tracing_check_open_get_tr() enforces only LOCKDOWN_TRACEFS and DAC with no capable() check. buffer_subbuf_size_kb and trace_pipe_raw are mode 0640 and are routinely delegated via tracefs gid=/mode= to tracing-group members on Android/Perfetto, ChromeOS, and developer kernels, matching prior CNA tracefs UAF scores.\nUI:N - Exploitation uses the attacker\u2019s own tracefs file descriptors and threads (open/read/close trace_pipe_raw while writing buffer_subbuf_size_kb). No separate victim mount, click, or configuration action is required.\nS:U - The use-after-free and double-free corrupt kernel ring-buffer pages and metadata within the same OS security authority. This enables local privilege escalation but does not cross VM, IOMMU, container-hypervisor, or hardware trust boundaries.\nC:H - ring_buffer_subbuf_order_set() can free the cached free_page after alloc_read_page has already claimed it, including after ring_buffer_read_page swaps it into the live reader page. Recycled heap contents are then copied to userspace via tracing_buffers_read, giving a high-impact disclosure primitive.\nI:H - The same race double-frees the page or installs a freed page as the live ring-buffer reader page, so later tracing writes and free_read_page hit attacker-reclaimable heap. This UAF/double-free is exploitable for arbitrary kernel writes and control-flow hijack, not merely a crash.\nA:H - Concurrent free of a still-in-use reader or spare page corrupts ring-buffer lists and causes kernel oops/panic on UAF or double-free. The attacker can retrigger the race at will through repeated subbuf resizes and raw-buffer reads."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/trace/ring_buffer.c"], "versions": [{"version": "8e7b58c27b3c567316a51079b375b846f9223bba", "lessThan": "8a496aaa3da6e8d545896c2370c7e617cc931ae2", "status": "affected", "versionType": "git"}, {"version": "8e7b58c27b3c567316a51079b375b846f9223bba", "lessThan": "6fcb0b745a0b80df62eae4a93ce52a2d061f4ac2", "status": "affected", "versionType": "git"}, {"version": "8e7b58c27b3c567316a51079b375b846f9223bba", "lessThan": "bf242baf58de03467f226c8e29554c9495dca7fc", "status": "affected", "versionType": "git"}, {"version": "8e7b58c27b3c567316a51079b375b846f9223bba", "lessThan": "24974bd0da1b47fd56c975533ead50abf754e74d", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["kernel/trace/ring_buffer.c"], "versions": [{"version": "6.8", "status": "affected"}, {"version": "0", "lessThan": "6.8", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.109", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.50", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2.4", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.12.109"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "6.18.50"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.8", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/8a496aaa3da6e8d545896c2370c7e617cc931ae2"}, {"url": "https://git.kernel.org/stable/c/6fcb0b745a0b80df62eae4a93ce52a2d061f4ac2"}, {"url": "https://git.kernel.org/stable/c/bf242baf58de03467f226c8e29554c9495dca7fc"}, {"url": "https://git.kernel.org/stable/c/24974bd0da1b47fd56c975533ead50abf754e74d"}], "title": "ring-buffer: Hold cpu_buffer::lock when resizing a subbuf", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["kernel/trace/ring_buffer.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "8a496aaa3da6e8d545896c2370c7e617cc931ae2", "status": "affected", "version": "8e7b58c27b3c567316a51079b375b846f9223bba", "versionType": "git"}, {"lessThan": "6fcb0b745a0b80df62eae4a93ce52a2d061f4ac2", "status": "affected", "version": "8e7b58c27b3c567316a51079b375b846f9223bba", "versionType": "git"}, {"lessThan": "bf242baf58de03467f226c8e29554c9495dca7fc", "status": "affected", "version": "8e7b58c27b3c567316a51079b375b846f9223bba", "versionType": "git"}, {"lessThan": "24974bd0da1b47fd56c975533ead50abf754e74d", "status": "affected", "version": "8e7b58c27b3c567316a51079b375b846f9223bba", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["kernel/trace/ring_buffer.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "6.8"}, {"lessThan": "6.8", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.109", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.50", "versionType": "semver"}, {"lessThanOrEqual": "7.2.*", "status": "unaffected", "version": "7.2.4", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.3", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Hold cpu_buffer::lock when resizing a subbuf\n\nBecause, ring_buffer_subbuf_order_set() can clear cpu_buffer->free_page,\nhold cpu_buffer->lock to prevent races with\nring_buffer_alloc_read_page() and ring_buffer_free_read_page()."}], "id": "CVE-2026-89501", "lastModified": "2026-10-19T09:17:44.300", "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"}]}, "published": "2026-09-11T20:19:32.303", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/24974bd0da1b47fd56c975533ead50abf754e74d"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/6fcb0b745a0b80df62eae4a93ce52a2d061f4ac2"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/8a496aaa3da6e8d545896c2370c7e617cc931ae2"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/bf242baf58de03467f226c8e29554c9495dca7fc"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel ring-buffer: Race condition can lead to system instability", "id": "2532254", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532254"}, "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-413", "details": ["A flaw was found in the Linux kernel's ring-buffer component. A race condition occurs when resizing a sub-buffer without properly holding the `cpu_buffer::lock`. This oversight can lead to concurrency issues with memory allocation and deallocation operations, potentially resulting in system instability or a denial of service."], "name": "CVE-2026-89501", "public_date": "2026-09-11T19:43:50Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89501\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89501\nhttps://git.kernel.org/stable/c/24974bd0da1b47fd56c975533ead50abf754e74d\nhttps://git.kernel.org/stable/c/6fcb0b745a0b80df62eae4a93ce52a2d061f4ac2\nhttps://git.kernel.org/stable/c/8a496aaa3da6e8d545896c2370c7e617cc931ae2\nhttps://git.kernel.org/stable/c/bf242baf58de03467f226c8e29554c9495dca7fc"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8e7b58c27b3c567316a51079b375b846f9223bba,8a496aaa3da6e8d545896c2370c7e617cc931ae2)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8e7b58c27b3c567316a51079b375b846f9223bba,6fcb0b745a0b80df62eae4a93ce52a2d061f4ac2)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8e7b58c27b3c567316a51079b375b846f9223bba,bf242baf58de03467f226c8e29554c9495dca7fc)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[8e7b58c27b3c567316a51079b375b846f9223bba,24974bd0da1b47fd56c975533ead50abf754e74d)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "6.8"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,6.8)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.109,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.50,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.2.4,7.3.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.3-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-09-12T10:00:08.637372+00:00", "updated": "2026-09-15T22:30:15.275253+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}