{"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":"2026-08-05T12:38:13.419Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:38:13.419Z"},"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":"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/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"}}}}