{"id":"CVE-2026-89500","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Make cpu_buffer::free_page a buffer_data_read_page\n\nDiscarding a cached reader page after a concurrent ring buffer resize\nuses the new global subbuf_order …","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Make cpu_buffer::free_page a buffer_data_read_page\n\nDiscarding a cached reader page after a concurrent ring buffer resize\nuses the new global subbuf_order …","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","cwe":["CWE-763","CWE-401"],"vendor":"Linux","product":"Linux","affected":["Linux >= 8e7b58c27b3c567316a51079b375b846f9223bba < d8f52dc3c3f1f987d8cf920ccd8d66590870bf3f","Linux >= 8e7b58c27b3c567316a51079b375b846f9223bba < a1dabe68fb53730bc0be60c5dbfd3f4c560084e7","Linux >= 8e7b58c27b3c567316a51079b375b846f9223bba < d787d509bdf6c88c85e095247daf7456cb7fb772","Linux >= 8e7b58c27b3c567316a51079b375b846f9223bba < 7a1fb95de5404134f8758c1295ce88986bdf117c","Linux 6.8"],"published":"2026-09-11","updated":"2026-10-03","sourceUpdated":"2026-10-03T11:17:42.450","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-89500","references":[{"url":"https://git.kernel.org/stable/c/7a1fb95de5404134f8758c1295ce88986bdf117c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a1dabe68fb53730bc0be60c5dbfd3f4c560084e7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d787d509bdf6c88c85e095247daf7456cb7fb772","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d8f52dc3c3f1f987d8cf920ccd8d66590870bf3f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89500.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89500"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532513"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89500"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89500"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89500.mbox"},{"url":"https://kernelcve.org/list/?q=CVE-2026-89500"}],"tags":["nvd","cve.org","csaf","vex","red-hat","score-dispute"],"epss":0.00168,"epssPercentile":0.06064,"scores":{"nvd":7.8,"vendor":5.5,"cna":7.8},"ingestedAt":"2026-09-14T15:23:07.475Z","slug":"CVE-2026-89500","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Make cpu_buffer::free_page a buffer_data_read_page\n\nDiscarding a cached reader page after a concurrent ring buffer resize\nuses the new global subbuf_order for the free_pages() call. This\nmismatched order may crashes the kernel or leaks memory because the cached\npage was allocated under the old size.\n\nSave the actual free_page order alongside the page address to ensure we\nalways refer to the correct value and do not rely on the potentially\nstalled cpu_buffer->subbuf_order value. The simplest is to make\nfree_page a buffer_data_read_page which already covers exactly what we\nneed: a page address and a page order.\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 · affected: Red Hat Enterprise Linux 10 · no fix planned: Red Hat Enterprise Linux 10 · updated 2026-10-24 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89500.json)","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":215296,"id":"CVE-2026-89500","ts":1791027882655,"field":"cvss","old":"7","new":"7.8"},{"seq":203931,"id":"CVE-2026-89500","ts":1789490227190,"field":"cvss","old":"4.1","new":"7"},{"seq":203930,"id":"CVE-2026-89500","ts":1789490227190,"field":"severity","old":"medium","new":"high"},{"seq":202899,"id":"CVE-2026-89500","ts":1789403732862,"field":"cvss","old":"7.8","new":"4.1"},{"seq":202898,"id":"CVE-2026-89500","ts":1789403732862,"field":"severity","old":"high","new":"medium"},{"seq":197998,"id":"CVE-2026-89500","ts":1789384321311,"field":"cvss","old":"4.1","new":"7.8"},{"seq":197997,"id":"CVE-2026-89500","ts":1789384321311,"field":"severity","old":"medium","new":"high"},{"seq":183508,"id":"CVE-2026-89500","ts":1789356675656,"field":"cvss","old":"7.8","new":"4.1"},{"seq":183507,"id":"CVE-2026-89500","ts":1789356675656,"field":"severity","old":"high","new":"medium"},{"seq":153290,"id":"CVE-2026-89500","ts":1789285349905,"field":"cvss","old":null,"new":"7.8"},{"seq":153289,"id":"CVE-2026-89500","ts":1789285349905,"field":"severity","old":"none","new":"high"},{"seq":147071,"id":"CVE-2026-89500","ts":1789270195046,"field":"cvss","old":null,"new":"4.1"},{"seq":147070,"id":"CVE-2026-89500","ts":1789270195046,"field":"severity","old":"none","new":"medium"}]}