CVE-2026-89503

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89503", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.715Z", "datePublished": "2026-09-11T19:43:51.357Z", "dateUpdated": "2026-10-19T08:47:54.761Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:47:54.761Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page()\n\nring_buffer_alloc_read_page() is racy with ring_buffer_subbuf_order_set,\nit can allocate a reader page with an outdated order. This isn't a big\nissue, the user can still re-allocate a new reader page and try again.\n\nHowever, what is more problematic is if the value of subbuf_order\nchanges in the middle of ring_buffer_alloc_read_page(). In that case,\nbpage->order might not match the actual allocated memory.\n\nUse bpage->order for the allocation to prevent this race."}], "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: read() on per_cpu/*/trace_pipe_raw or snapshot_raw (tracing_buffers_read -> ring_buffer_alloc_read_page) racing with write() to buffer_subbuf_size_kb. No network, adjacent-radio, or physical path reaches this code.\nAC:L - The attacker controls both sides: one thread reads trace_pipe_raw while another writes buffer_subbuf_size_kb. GFP_KERNEL in alloc_cpu_data sleeps, so subbuf_order can change between the two reads in ring_buffer_alloc_read_page(); the race is reliably retried.\nPR:L - tracing_check_open_get_tr() enforces only LOCKDOWN_TRACEFS and DAC with no capable() check. trace_pipe_raw is 0440 and buffer_subbuf_size_kb is 0640, routinely delegated via gid=/mode= to tracing-group members on Android/Perfetto, ChromeOS, and developer systems.\nUI:N - Exploitation uses the attacker's own tracefs file descriptors and threads. No separate victim mount, click, or configuration action is required beyond the attacker holding tracefs access.\nS:U - Wrong-order page allocation and free corrupt the kernel buddy allocator and ring-buffer pages within the same OS security authority. This enables local privilege escalation but does not cross VM, IOMMU, or hardware trust boundaries.\nC:H - When bpage->order does not match the alloc_pages() size, later copy_to_user of a stale page_size and ring_buffer_read_page memcpy/memset over-read adjacent kernel pages, and wrong-order free_pages() corrupts the buddy allocator, yielding arbitrary kernel reads.\nI:H - free_pages() with a larger order than allocated, or memcpy/memset into an undersized sub-buffer when reader_page->order later matches the stale bpage->order, corrupts adjacent pages and the buddy allocator, which is exploitable for arbitrary kernel writes.\nA:H - Wrong-order free_pages() and out-of-bounds writes on undersized compound pages crash the kernel via buddy-allocator corruption or oops in ring_buffer_read_page/free_read_page. The attacker can retrigger the race at will."}]}], "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": "bce761d757452ba5eb77e11fecc37a04b67494e7", "lessThan": "2313ff69bd237aad264a5913907f374f958335a2", "status": "affected", "versionType": "git"}, {"version": "bce761d757452ba5eb77e11fecc37a04b67494e7", "lessThan": "2dc510957fe8fd098ab3c3147ebdf34d00cd2734", "status": "affected", "versionType": "git"}, {"version": "bce761d757452ba5eb77e11fecc37a04b67494e7", "lessThan": "53106e9262a310ef2c9a9321168c03705940c678", "status": "affected", "versionType": "git"}, {"version": "bce761d757452ba5eb77e11fecc37a04b67494e7", "lessThan": "e743527c5bfdceda1095bc0a9e596e2aebb6a9c3", "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": "6.12.112", "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": "6.12.112"}, {"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/2313ff69bd237aad264a5913907f374f958335a2"}, {"url": "https://git.kernel.org/stable/c/2dc510957fe8fd098ab3c3147ebdf34d00cd2734"}, {"url": "https://git.kernel.org/stable/c/53106e9262a310ef2c9a9321168c03705940c678"}, {"url": "https://git.kernel.org/stable/c/e743527c5bfdceda1095bc0a9e596e2aebb6a9c3"}], "title": "ring-buffer: Fix subbuf resize race with ring_buffer_alloc_read_page()", "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": "2313ff69bd237aad264a5913907f374f958335a2", "status": "affected", "version": "bce761d757452ba5eb77e11fecc37a04b67494e7", "versionType": "git"}, {"lessThan": "2dc510957fe8fd098ab3c3147ebdf34d00cd2734", "status": "affected", "version": "bce761d757452ba5eb77e11fecc37a04b67494e7", "versionType": "git"}, {"lessThan": "53106e9262a310ef2c9a9321168c03705940c678", "status": "affected", "version": "bce761d757452ba5eb77e11fecc37a04b67494e7", "versionType": "git"}, {"lessThan": "e743527c5bfdceda1095bc0a9e596e2aebb6a9c3", "status": "affected", "version": "bce761d757452ba5eb77e11fecc37a04b67494e7", "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": "6.12.112", "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: Fix subbuf resize race with ring_buffer_alloc_read_page()\n\nring_buffer_alloc_read_page() is racy with ring_buffer_subbuf_order_set,\nit can allocate a reader page with an outdated order. This isn't a big\nissue, the user can still re-allocate a new reader page and try again.\n\nHowever, what is more problematic is if the value of subbuf_order\nchanges in the middle of ring_buffer_alloc_read_page(). In that case,\nbpage->order might not match the actual allocated memory.\n\nUse bpage->order for the allocation to prevent this race."}], "id": "CVE-2026-89503", "lastModified": "2026-10-19T09:17:44.507", "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": "2026-09-11T20:19:32.547", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2313ff69bd237aad264a5913907f374f958335a2"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2dc510957fe8fd098ab3c3147ebdf34d00cd2734"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/53106e9262a310ef2c9a9321168c03705940c678"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/e743527c5bfdceda1095bc0a9e596e2aebb6a9c3"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel ring-buffer: Denial of Service due to subbuffer resize race condition", "id": "2532017", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532017"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-367", "details": ["A flaw was found in the Linux kernel's ring-buffer component. A race condition exists in the `ring_buffer_alloc_read_page()` function when it interacts with `ring_buffer_subbuf_order_set`. This can lead to an incorrect memory allocation where the buffer page's order (`bpage->order`) does not match the actual allocated memory. This mismatch could potentially cause system instability or a denial of service."], "name": "CVE-2026-89503", "package_state": [{"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-8", "product_name": "Red Hat OpenShift Container Platform 4"}, {"cpe": "cpe:/a:redhat:openshift:4", "fix_state": "Fix deferred", "package_name": "openshift/ose-rhel-coreos-9", "product_name": "Red Hat OpenShift Container Platform 4"}], "public_date": "2026-09-11T19:43:51Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89503\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89503\nhttps://git.kernel.org/stable/c/2dc510957fe8fd098ab3c3147ebdf34d00cd2734\nhttps://git.kernel.org/stable/c/53106e9262a310ef2c9a9321168c03705940c678\nhttps://git.kernel.org/stable/c/e743527c5bfdceda1095bc0a9e596e2aebb6a9c3"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[bce761d757452ba5eb77e11fecc37a04b67494e7,2dc510957fe8fd098ab3c3147ebdf34d00cd2734)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[bce761d757452ba5eb77e11fecc37a04b67494e7,53106e9262a310ef2c9a9321168c03705940c678)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[bce761d757452ba5eb77e11fecc37a04b67494e7,e743527c5bfdceda1095bc0a9e596e2aebb6a9c3)"}}], "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": "generic", "value": "[0,6.8)"}}, {"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": "2026-09-12T08:15:06.675387+00:00", "updated": "2026-09-15T22:30:15.274539+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}