{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-64437", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-64437", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-07-25T08:51:11.072Z", "updatedAt": "2026-08-17T04:55:38.646Z", "importedAt": "2026-10-24T01:58:25.636Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "ksmbd: fix use-after-free of a deferred file_lock on SMB2_CLOSE then SMB2_CANCEL", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free of a deferred file_lock on SMB2_CLOSE then SMB2_CANCEL\n\nCommit f580d27e8928 (\"ksmbd: fix use-after-free of a deferred file_lock on\ndouble SMB2_CANCEL\") made smb2_cancel() skip a work whose state is\nKSMBD_WORK_CANCELLED, so its cancel_fn cannot be fired a second time. But\nKSMBD_WORK has three states (ACTIVE, CANCELLED, CLOSED), and the same\nfreeing producer path is reached for CLOSED too:\n\n SMB2_CLOSE on the locking handle -> set_close_state_blocked_works() sets\n the deferred work's state to KSMBD_WORK_CLOSED and wakes the smb2_lock()\n worker. The worker takes the non-ACTIVE early-exit, locks_free_lock()s\n the file_lock and, because the state is not KSMBD_WORK_CANCELLED, takes\n the STATUS_RANGE_NOT_LOCKED branch with \"goto out2\" -- which, like the\n cancelled branch, skips release_async_work(). The work stays on\n conn->async_requests with a live cancel_fn = smb2_remove_blocked_lock\n pointing at the freed file_lock.\n\nA subsequent SMB2_CANCEL for the same AsyncId then passes the\nKSMBD_WORK_CANCELLED-only guard (its state is KSMBD_WORK_CLOSED), so\nsmb2_cancel() fires cancel_fn again over the freed file_lock -- the same\nuse-after-free fixed, via SMB2_CLOSE instead of a first SMB2_CANCEL:\n\n BUG: KASAN: slab-use-after-free in __locks_delete_block\n __locks_delete_block\n locks_delete_block\n ksmbd_vfs_posix_lock_unblock\n smb2_remove_blocked_lock\n smb2_cancel <- 2nd SMB2_CANCEL fires cancel_fn\n handle_ksmbd_work\n Allocated by ...: locks_alloc_lock <- smb2_lock\n Freed by ...: locks_free_lock <- smb2_lock (non-ACTIVE early-exit)\n ... cache file_lock_cache of size 192\n\nReproduced on mainline 7.1-rc7 (which already contains f580d27e8928) with\nKASAN by an authenticated SMB client; the double-SMB2_CANCEL control is\nsilent on that kernel, so the splat is attributable to the CLOSE trigger.\n\nOnly an ACTIVE deferred work may have its cancel_fn fired: both terminal\nstates (CANCELLED and CLOSED) reach the smb2_lock() early-exit that frees\nthe file_lock and skips release_async_work(). Guard on KSMBD_WORK_ACTIVE\nso any non-active work is skipped.", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "b7063c7426ea5a4d15e01b60538718765392f49d", "status": "affected", "versionType": "git", "lessThan": "a796ba4e61d5e14e07b79a359faac69f8f9b22a3" }, { "version": "0da2e073f9cbf4985a0fd9acb71bc5ff599f8afd", "status": "affected", "versionType": "git", "lessThan": "b8e274e69ab09222c7a552c7c0c1eef9ce627fc1" }, { "version": "89ae9df09d2c1fb4a4eb495c113a7ce1dca34147", "status": "affected", "versionType": "git", "lessThan": "ddb9239828336b36d8a3ef5943fdffb2f55b6508" }, { "version": "14d2eee0193ac3cd1bf3d014373449f0b8d35d6d", "status": "affected", "versionType": "git", "lessThan": "94083db751930b1540ddff2b54d4677549c57f81" }, { "version": "f580d27e8928828693df44ba2db0fffdbe11dfea", "status": "affected", "versionType": "git", "lessThan": "12c36c99655f325befe50c26842f7deca414c381" }, { "version": "f580d27e8928828693df44ba2db0fffdbe11dfea", "status": "affected", "versionType": "git", "lessThan": "10f293a07f9e10e988b0ae44e2e99c631f5a68e0" }, { "version": "2b2eda2821cff1d1b5a423b6ee7d8fc6fbc8e694", "status": "affected", "versionType": "git" }, { "version": "6.1.176", "status": "affected", "versionType": "semver", "lessThan": "6.1.178" }, { "version": "6.6.143", "status": "affected", "versionType": "semver", "lessThan": "6.6.145" }, { "version": "6.12.94", "status": "affected", "versionType": "semver", "lessThan": "6.12.96" }, { "version": "6.18.36", "status": "affected", "versionType": "semver", "lessThan": "6.18.39" }, { "version": "7.0.13", "status": "affected", "versionType": "semver", "lessThan": "7.1" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "7.1", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "7.1" }, { "version": "6.1.178", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.145", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.96", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.39", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.1.4", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.1.*" }, { "version": "7.2", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }