{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64016", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.027Z", "datePublished": "2026-07-19T15:39:11.266Z", "dateUpdated": "2026-09-14T11:58:34.345Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-09-14T11:58:34.345Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix durable reconnect error path file lifetime\n\nAfter a durable reconnect succeeds, ksmbd_reopen_durable_fd() republishes\nthe same ksmbd_file into the session volatile-id table. If smb2_open()\nthen takes a later error path, cleanup first calls ksmbd_fd_put(work, fp)\nand then unconditionally calls ksmbd_put_durable_fd(dh_info.fp).\n\nIn this case fp and dh_info.fp are the same object. The first put drops the\nreconnect lookup reference, but the final durable put can run\n__ksmbd_close_fd(NULL, fp). Because the final close is not session-aware,\nit can free the file object without removing the volatile-id entry that was\njust published into the session table.\n\nUse the session-aware put for the final reconnect drop when the reconnect\nhad already succeeded and the error path is cleaning up the republished\nfile. Earlier reconnect failures, before fp is assigned to dh_info.fp, keep\nusing the durable-only put path." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL" }, "scenarios": [ { "lang": "en", "value": "AV:N - The vulnerability is reached through ksmbd's in-kernel SMB2 server on TCP port 445 via SMB2_CREATE durable-handle reconnect processing in smb2_open(), reachable by any remote SMB client that can connect to the server.\nAC:L - An authenticated attacker can fully control the durable reconnect sequence (open with durable handle, disconnect to preserve it, reconnect, then force a post-reconnect error such as ksmbd_iov_pin_rsp() ENOMEM) and immediately exercise the stale volatile file ID via further SMB2 operations.\nPR:N - Exploitation requires only network reachability to ksmbd and valid SMB session credentials (guest or any share user); no elevated kernel privileges, capabilities, or local access are needed beyond what any remote SMB client possesses.\nUI:N - No victim user interaction is required beyond the server running ksmbd with durable handles enabled; the attacker drives the entire reconnect-and-error sequence over the network.\nS:U - The use-after-free corrupts kernel heap memory within the ksmbd server context and can lead to privilege escalation on the host, but does not cross a VM, container, or IOMMU security boundary.\nC:H - Freeing the ksmbd_file while its volatile ID remains in the session IDR creates a use-after-free; subsequent ksmbd_lookup_fd_slow() dereferences freed slab memory, enabling kernel information disclosure.\nI:H - The UAF corrupts kernel heap objects (struct ksmbd_file in the filp kmem cache) and can be leveraged with heap grooming for arbitrary kernel memory writes or code execution.\nA:H - Use-after-free of the ksmbd_file object can cause kernel oopses or panics when freed memory is reused or dereferenced during subsequent SMB2 file operations on the stale volatile ID." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/smb2pdu.c" ], "versions": [ { "version": "f0ff7f12398e85b3a11745ff7feab6246f3d75c2", "lessThan": "5e641e4ee0bc1937408d41051a908ad4151be63b", "status": "affected", "versionType": "git" }, { "version": "4db3dcac84c2f14a45ae201efb38de1fb1bfc009", "lessThan": "478bfaa036bd0c7e179acff8b8484bccdee3b8c7", "status": "affected", "versionType": "git" }, { "version": "ce2e164c1c51c3f7813b80f8c926836e896bcbb3", "lessThan": "a1a39f227c80cbf369767badc32cba2b225147d1", "status": "affected", "versionType": "git" }, { "version": "97a0cd55283b4e63fd92804da91c8d9896adcad9", "lessThan": "6cb0b9385320110fe24a5d5ac0000ade4bb3a3f3", "status": "affected", "versionType": "git" }, { "version": "1baff47b81f94f9231c91236aa511420d0e266b9", "lessThan": "3515503322f4819277091839eed46b695096aca5", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/smb2pdu.c" ], "versions": [ { "version": "6.18.33", "lessThan": "6.18.34", "status": "affected", "versionType": "semver" }, { "version": "7.0.10", "lessThan": "7.0.11", "status": "affected", "versionType": "semver" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.18.33", "versionEndExcluding": "6.18.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "7.0.10", "versionEndExcluding": "7.0.11" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/5e641e4ee0bc1937408d41051a908ad4151be63b" }, { "url": "https://git.kernel.org/stable/c/478bfaa036bd0c7e179acff8b8484bccdee3b8c7" }, { "url": "https://git.kernel.org/stable/c/a1a39f227c80cbf369767badc32cba2b225147d1" }, { "url": "https://git.kernel.org/stable/c/6cb0b9385320110fe24a5d5ac0000ade4bb3a3f3" }, { "url": "https://git.kernel.org/stable/c/3515503322f4819277091839eed46b695096aca5" } ], "title": "ksmbd: fix durable reconnect error path file lifetime", "x_generator": { "engine": "bippy-1.2.0" } } } }