{"id":"CVE-2026-89639","title":"cifs: use cifs_invalidate_cache() in cifs_do_truncate() for O_TRUNC","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: use cifs_invalidate_cache() in cifs_do_truncate() for O_TRUNC\n\ncifs_do_truncate() is invoked from cifs_open() without i_rwsem, so it\ncannot use cifs_resize_file_l…","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N","cvssSource":"cna","cwe":["CWE-524"],"vendor":"Linux","product":"Linux","affected":["Linux >= efbcecdecefc26fa062c0e8210533ccad7d6bd4a < 8b9b10fe5b8b492b27b9f4546742ea541a650213","Linux >= fa724e235cfdb0fb0bb427d0f9dfe864ae27403e < 81fc3868a7f726980ff845c1d0d271051e5f0f45","Linux >= fa724e235cfdb0fb0bb427d0f9dfe864ae27403e < 364b183230586a62660a7280c1eb20138338eeb5","Linux 6838bcac954487cc0a3c8a4ee1b3a3a30e244dc9","Linux 75640976cf474eb41682a13f2dbe9534ac26ca50","Linux 3513f3931c579ba2a715784c6dedc59e0d9282ee","Linux >= 6.18.44 < 6.18.50","Linux >= 6.12.105 < 6.13","Linux >= 7.1.8 < 7.2","Linux 7.2"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:50:11.190Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89639","references":[{"url":"https://git.kernel.org/stable/c/8b9b10fe5b8b492b27b9f4546742ea541a650213"},{"url":"https://git.kernel.org/stable/c/81fc3868a7f726980ff845c1d0d271051e5f0f45"},{"url":"https://git.kernel.org/stable/c/364b183230586a62660a7280c1eb20138338eeb5"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89639.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89639"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532382"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89639"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89639"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89639.mbox"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.0017,"epssPercentile":0.06302,"scores":{"cna":7.1,"vendor":5.5},"ingestedAt":"2026-09-14T15:23:07.473Z","slug":"CVE-2026-89639","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\ncifs: use cifs_invalidate_cache() in cifs_do_truncate() for O_TRUNC\n\ncifs_do_truncate() is invoked from cifs_open() without i_rwsem, so it\ncannot use cifs_resize_file_locked() to perform a proper fscache cookie\nresize.  Instead, add cifs_invalidate_cache() after cifs_setsize().\n\ncifs_invalidate_cache() calls fscache_invalidate(), which works without\nholding i_rwsem: it unconditionally increments inval_counter and sets\nFSCACHE_COOKIE_NO_DATA_TO_READ, ensuring that stale cached data is not\nserved once the cookie is later activated by fscache_use_cookie().\nTruncation to zero leaves no valid cached data, making invalidation the\ncorrect semantic here.\n\n## Affected\n\n- `Linux >= efbcecdecefc26fa062c0e8210533ccad7d6bd4a < 8b9b10fe5b8b492b27b9f4546742ea541a650213`\n- `Linux >= fa724e235cfdb0fb0bb427d0f9dfe864ae27403e < 81fc3868a7f726980ff845c1d0d271051e5f0f45`\n- `Linux >= fa724e235cfdb0fb0bb427d0f9dfe864ae27403e < 364b183230586a62660a7280c1eb20138338eeb5`\n- `Linux 6838bcac954487cc0a3c8a4ee1b3a3a30e244dc9`\n- `Linux 75640976cf474eb41682a13f2dbe9534ac26ca50`\n- `Linux 3513f3931c579ba2a715784c6dedc59e0d9282ee`\n- `Linux >= 6.18.44 < 6.18.50`\n- `Linux >= 6.12.105 < 6.13`\n- `Linux >= 7.1.8 < 7.2`\n- `Linux 7.2`\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 2026-09-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89639.json)","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":224649,"id":"CVE-2026-89639","ts":1792401458183,"field":"cvss","old":"5.5","new":"7.1"},{"seq":224648,"id":"CVE-2026-89639","ts":1792401458183,"field":"severity","old":"medium","new":"high"},{"seq":205438,"id":"CVE-2026-89639","ts":1789576713916,"field":"cvss","old":"3.3","new":"5.5"},{"seq":205437,"id":"CVE-2026-89639","ts":1789576713916,"field":"severity","old":"low","new":"medium"},{"seq":202812,"id":"CVE-2026-89639","ts":1789403731311,"field":"cvss","old":"7.1","new":"3.3"},{"seq":202811,"id":"CVE-2026-89639","ts":1789403731311,"field":"severity","old":"high","new":"low"},{"seq":197821,"id":"CVE-2026-89639","ts":1789384320541,"field":"cvss","old":"3.3","new":"7.1"},{"seq":197820,"id":"CVE-2026-89639","ts":1789384320541,"field":"severity","old":"low","new":"high"},{"seq":183331,"id":"CVE-2026-89639","ts":1789356674897,"field":"cvss","old":"7.1","new":"3.3"},{"seq":183330,"id":"CVE-2026-89639","ts":1789356674897,"field":"severity","old":"high","new":"low"},{"seq":153482,"id":"CVE-2026-89639","ts":1789285350695,"field":"cvss","old":null,"new":"7.1"},{"seq":153481,"id":"CVE-2026-89639","ts":1789285350695,"field":"severity","old":"none","new":"high"},{"seq":147289,"id":"CVE-2026-89639","ts":1789270207313,"field":"cvss","old":null,"new":"3.3"},{"seq":147288,"id":"CVE-2026-89639","ts":1789270207313,"field":"severity","old":"none","new":"low"},{"seq":109044,"id":"CVE-2026-89639","ts":1789183730086,"field":"cvss","old":null,"new":"3.3"},{"seq":109043,"id":"CVE-2026-89639","ts":1789183730086,"field":"severity","old":"none","new":"low"}]}