{"id":"CVE-2026-89499","title":"ring-buffer: Stop remote reader update when page swap fails","summary":"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 cat…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-390"],"vendor":"Linux","product":"Linux","affected":["Linux >= 2e67fabd8b77c4f482df9b211bca1b495c6c2c24 < a14a97048e48471e283d76879b83d2ae323e0722","Linux >= 2e67fabd8b77c4f482df9b211bca1b495c6c2c24 < 5eab74874d11160725c42ab676ba97a797a362eb","Linux 7.1"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:47:50.883Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89499","references":[{"url":"https://git.kernel.org/stable/c/a14a97048e48471e283d76879b83d2ae323e0722"},{"url":"https://git.kernel.org/stable/c/5eab74874d11160725c42ab676ba97a797a362eb"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89499.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89499"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532499"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89499"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89499"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89499.mbox"}],"tags":["cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00165,"epssPercentile":0.05672,"scores":{"cna":7.8,"vendor":5.5},"ingestedAt":"2026-09-14T15:23:07.475Z","slug":"CVE-2026-89499","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= 2e67fabd8b77c4f482df9b211bca1b495c6c2c24 < a14a97048e48471e283d76879b83d2ae323e0722`\n- `Linux >= 2e67fabd8b77c4f482df9b211bca1b495c6c2c24 < 5eab74874d11160725c42ab676ba97a797a362eb`\n- `Linux 7.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Moderate · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89499.json)","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":224730,"id":"CVE-2026-89499","ts":1792401507818,"field":"cvss","old":"5.5","new":"7.8"},{"seq":224729,"id":"CVE-2026-89499","ts":1792401507818,"field":"severity","old":"medium","new":"high"},{"seq":202893,"id":"CVE-2026-89499","ts":1789403732838,"field":"cvss","old":"7.8","new":"5.5"},{"seq":202892,"id":"CVE-2026-89499","ts":1789403732838,"field":"severity","old":"high","new":"medium"},{"seq":198002,"id":"CVE-2026-89499","ts":1789384321328,"field":"cvss","old":"5.5","new":"7.8"},{"seq":198001,"id":"CVE-2026-89499","ts":1789384321328,"field":"severity","old":"medium","new":"high"},{"seq":183512,"id":"CVE-2026-89499","ts":1789356675671,"field":"cvss","old":"7.8","new":"5.5"},{"seq":183511,"id":"CVE-2026-89499","ts":1789356675671,"field":"severity","old":"high","new":"medium"},{"seq":153288,"id":"CVE-2026-89499","ts":1789285349897,"field":"cvss","old":null,"new":"7.8"},{"seq":153287,"id":"CVE-2026-89499","ts":1789285349897,"field":"severity","old":"none","new":"high"},{"seq":147123,"id":"CVE-2026-89499","ts":1789270195265,"field":"cvss","old":null,"new":"5.5"},{"seq":147122,"id":"CVE-2026-89499","ts":1789270195265,"field":"severity","old":"none","new":"medium"},{"seq":108870,"id":"CVE-2026-89499","ts":1789183729336,"field":"cvss","old":null,"new":"5.5"},{"seq":108869,"id":"CVE-2026-89499","ts":1789183729336,"field":"severity","old":"none","new":"medium"}]}