CVE-2026-89499

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-89499", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.715Z", "datePublished": "2026-09-11T19:43:48.752Z", "dateUpdated": "2026-10-19T08:47:50.883Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:47:50.883Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Stop remote reader update when page swap fails\n\nThe remote swap_reader_page callback can return -EBUSY when the writer\nmoves the head before the remote catches it, particularly during an event\nstorm on a small buffer. __rb_get_reader_page_from_remote() currently\nwarns about that failure but continues with the unchanged reader ID and\nrearranges the local page list as though the swap succeeded.\n\nHandle the callback failure as a recoverable error. Report it with\npr_warn_ratelimited() and return NULL. Callers already handle a NULL reader\npage as a failed attempt. This avoids splicing the same page as both the\nprevious and new reader without flooding the log under contention."}], "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 by a local read of tracefs remotes/*/trace_pipe or remotes/*/trace, which calls ring_buffer_peek/consume then rb_get_reader_page() and __rb_get_reader_page_from_remote(). No network, adjacent-radio, or physical-device path reaches this remote reader swap.\nAC:L - An attacker with tracefs access sets a small remotes/*/buffer_size_kb, enables tracing, generates an event storm via remotes/*/write_event or KVM hyp events, and reads trace_pipe. That is the documented -EBUSY case; the attacker controls writer load and the reader swap, so the failed-swap path is reliably hit.\nPR:L - remotes/ files are mode 0440/0640 and use custom fops with no capable() or tracing_check_open_get_tr() check, only DAC. tracing-gid mounts on Android eng/Perfetto, ChromeOS, and developer kernels grant this to unprivileged users, matching prior CNA tracefs scores.\nUI:N - The attacker opens, configures, and reads their own remotes/*/trace_pipe and related tracefs files. No separate victim mount, click, or other user action is required.\nS:U - The corruption is of host kernel ring-buffer buffer_page lists and reader metadata in the same OS security authority. A host-local tracefs user cannot use this as a VM/IOMMU/guest-to-host escape.\nC:H - On swap failure the kernel still splices the unchanged reader page into the list and shares it with the remote writer. Torn event headers make rb_event_length() return unbounded sizes, and later peeks follow corrupted buffer_page pointers, enabling out-of-bounds kernel reads.\nI:H - __rb_get_reader_page_from_remote() writes list.next/list.prev as if the swap succeeded, creating a self-referential reader and unlinking the real head. Subsequent swaps and rb_inc_page/rb_list_head_clear store further pointers on that corrupted topology, which is exploitable kernel metadata corruption.\nA:H - The failed-swap path hits WARN_ON_ONCE(prev_reader == new_reader), can infinite-loop walking the spliced list, and oopses on corrupted page pointers. panic_on_warn makes those WARNs a kernel panic, and the attacker can retrigger the path 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": "2e67fabd8b77c4f482df9b211bca1b495c6c2c24", "lessThan": "a14a97048e48471e283d76879b83d2ae323e0722", "status": "affected", "versionType": "git"}, {"version": "2e67fabd8b77c4f482df9b211bca1b495c6c2c24", "lessThan": "5eab74874d11160725c42ab676ba97a797a362eb", "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": "7.1", "status": "affected"}, {"version": "0", "lessThan": "7.1", "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": "7.1", "versionEndExcluding": "7.2.4"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.1", "versionEndExcluding": "7.3"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/a14a97048e48471e283d76879b83d2ae323e0722"}, {"url": "https://git.kernel.org/stable/c/5eab74874d11160725c42ab676ba97a797a362eb"}], "title": "ring-buffer: Stop remote reader update when page swap fails", "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": "a14a97048e48471e283d76879b83d2ae323e0722", "status": "affected", "version": "2e67fabd8b77c4f482df9b211bca1b495c6c2c24", "versionType": "git"}, {"lessThan": "5eab74874d11160725c42ab676ba97a797a362eb", "status": "affected", "version": "2e67fabd8b77c4f482df9b211bca1b495c6c2c24", "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": "7.1"}, {"lessThan": "7.1", "status": "unaffected", "version": "0", "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: Stop remote reader update when page swap fails\n\nThe remote swap_reader_page callback can return -EBUSY when the writer\nmoves the head before the remote catches it, particularly during an event\nstorm on a small buffer. __rb_get_reader_page_from_remote() currently\nwarns about that failure but continues with the unchanged reader ID and\nrearranges the local page list as though the swap succeeded.\n\nHandle the callback failure as a recoverable error. Report it with\npr_warn_ratelimited() and return NULL. Callers already handle a NULL reader\npage as a failed attempt. This avoids splicing the same page as both the\nprevious and new reader without flooding the log under contention."}], "id": "CVE-2026-89499", "lastModified": "2026-10-19T09:17:44.073", "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": "2026-09-11T20:19:32.063", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/5eab74874d11160725c42ab676ba97a797a362eb"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/a14a97048e48471e283d76879b83d2ae323e0722"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: Linux kernel: Ring-buffer vulnerability causes log flooding", "id": "2532499", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2532499"}, "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-390", "details": ["A flaw was found in the Linux kernel's ring-buffer component. When a remote reader update fails during a page swap, the system incorrectly proceeds as if the swap succeeded. This can lead to log flooding, potentially causing a denial of service by exhausting system resources or hindering system diagnostics."], "name": "CVE-2026-89499", "public_date": "2026-09-11T19:43:48Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-89499\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-89499\nhttps://git.kernel.org/stable/c/5eab74874d11160725c42ab676ba97a797a362eb\nhttps://git.kernel.org/stable/c/a14a97048e48471e283d76879b83d2ae323e0722"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[2e67fabd8b77c4f482df9b211bca1b495c6c2c24,a14a97048e48471e283d76879b83d2ae323e0722)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[2e67fabd8b77c4f482df9b211bca1b495c6c2c24,5eab74874d11160725c42ab676ba97a797a362eb)"}}], "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": "[7.1,7.1]"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,7.1)"}}, {"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": "2026-09-12T13:30:14.157076+00:00", "updated": "2026-09-21T01:15:03.756528+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}