{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-35869", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-17T13:50:33.108Z", "datePublished": "2024-05-19T08:34:27.645Z", "dateUpdated": "2026-08-05T11:30:31.558Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:30:31.558Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: guarantee refcounted children from parent session\n\nAvoid potential use-after-free bugs when walking DFS referrals,\nmounting and performing DFS failover by ensuring that all children\nfrom parent @tcon->ses are also refcounted. They're all needed across\nthe entire DFS mount. Get rid of @tcon->dfs_ses_list while we're at\nit, too." } ], "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 vulnerable refcounting is driven entirely by DFS referral responses from a remote SMB peer — the server chooses the nesting depth, target types, interlink/storage flags, and referral TTL that produce the unbalanced `dfs_root_ses` chain. A malicious/compromised SMB server, an SMB MITM, or an attacker controlling DNS for DFS target hostnames reaches this over the network.\nAC:L - This is a deterministic refcount imbalance, not a race: the server simply returns a referral topology three or more levels deep (limit is MAX_NESTED_LINKS=8) and can force the failover/reconnect path arbitrarily often by dropping TCP or setting a short TTL. Heap grooming for the subsequent UAF is routine and fully under attacker control.\nPR:N - The remote server holds no privileges on the victim host — CIFS authenticates the client to the server, not the reverse, so nothing gates the referral data on the way to the vulnerable code. The runtime `dfs_cache_refresh()` worker and DFS failover run in kernel context with no local account required at all; even the local automount path (`cifs_d_automount`) has no capability check.\nUI:N - Once a normal cifs DFS mount exists (fstab/autofs, standing configuration, not a per-exploit action), the server triggers the vulnerable failover and `dfs_cache_work` refresh paths on its own schedule with no victim participation. The automount path is likewise reached by ordinary directory traversal, not a deliberate security decision.\nS:U - The corrupted `struct cifs_ses` objects and the resulting control-flow hijack are confined to the kernel's own security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - Use-after-free of `struct cifs_ses`, which is dereferenced for `ses->server`, `ses->tcon_ipc`, `ses->Suid` and holds SMB credentials and signing/session keys; reclaiming the freed slab object yields an arbitrary-read primitive and leaks sensitive session material.\nI:H - The DFS failover path performs `server->ops->tree_connect(...)` — an indirect call through a function pointer read out of the freed session's `server` field — giving a direct control-flow hijack primitive once the object is reclaimed with attacker-groomed heap data.\nA:H - Dereferencing and spin-locking a freed `struct cifs_ses` from the reconnect path and the `dfs_cache_refresh` workqueue causes kernel oops/panic, and the double-put on the mount error path corrupts the session list. The server can trigger it repeatedly." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/client/cifsglob.h", "fs/smb/client/cifsproto.h", "fs/smb/client/connect.c", "fs/smb/client/dfs.c", "fs/smb/client/dfs.h", "fs/smb/client/dfs_cache.c", "fs/smb/client/misc.c" ], "versions": [ { "version": "8e3554150d6c80a84b3cb046615d1a0e943811dc", "lessThan": "645f332c6b63499cc76197f9b6bffcc659ba64cc", "status": "affected", "versionType": "git" }, { "version": "8e3554150d6c80a84b3cb046615d1a0e943811dc", "lessThan": "e1db9ae87b7148c021daee1fcc4bc71b2ac58a79", "status": "affected", "versionType": "git" }, { "version": "8e3554150d6c80a84b3cb046615d1a0e943811dc", "lessThan": "062a7f0ff46eb57aff526897bd2bebfdb1d3046a", "status": "affected", "versionType": "git" }, { "version": "f30d226bcc9f0e2d97b4a6e94c43a28148fbeab6", "status": "affected", "versionType": "git" }, { "version": "c082c3be0f96e759ff2e361d929832fda0b93851", "status": "affected", "versionType": "git" }, { "version": "6.2.15", "lessThan": "6.3", "status": "affected", "versionType": "semver" }, { "version": "6.3.2", "lessThan": "6.4", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/client/cifsglob.h", "fs/smb/client/cifsproto.h", "fs/smb/client/connect.c", "fs/smb/client/dfs.c", "fs/smb/client/dfs.h", "fs/smb/client/dfs_cache.c", "fs/smb/client/misc.c" ], "versions": [ { "version": "6.4", "status": "affected" }, { "version": "0", "lessThan": "6.4", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.29", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.8.5", "lessThanOrEqual": "6.8.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.9", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.6.29" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.8.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4", "versionEndExcluding": "6.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2.15" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/645f332c6b63499cc76197f9b6bffcc659ba64cc" }, { "url": "https://git.kernel.org/stable/c/e1db9ae87b7148c021daee1fcc4bc71b2ac58a79" }, { "url": "https://git.kernel.org/stable/c/062a7f0ff46eb57aff526897bd2bebfdb1d3046a" } ], "title": "smb: client: guarantee refcounted children from parent session", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "problemTypes": [ { "descriptions": [ { "type": "CWE", "cweId": "CWE-416", "lang": "en", "description": "CWE-416 Use After Free" } ] } ], "affected": [ { "vendor": "linux", "product": "linux_kernel", "cpes": [ "cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*" ], "defaultStatus": "unknown", "versions": [ { "version": "1da177e4c3f4", "status": "affected", "lessThan": "645f332c6b63", "versionType": "custom" } ] }, { "vendor": "linux", "product": "linux_kernel", "cpes": [ "cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*" ], "defaultStatus": "unknown", "versions": [ { "version": "1da177e4c3f4", "status": "affected", "lessThan": "e1db9ae87b71", "versionType": "custom" } ] }, { "vendor": "linux", "product": "linux_kernel", "cpes": [ "cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*" ], "defaultStatus": "unknown", "versions": [ { "version": "1da177e4c3f4", "status": "affected", "lessThan": "062a7f0ff46e", "versionType": "custom" } ] }, { "vendor": "linux", "product": "linux_kernel", "cpes": [ "cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*" ], "defaultStatus": "unknown", "versions": [ { "version": "6.6.29", "status": "unaffected", "lessThanOrEqual": "6.6.*", "versionType": "custom" } ] }, { "vendor": "linux", "product": "linux_kernel", "cpes": [ "cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*" ], "defaultStatus": "unknown", "versions": [ { "version": "6.8.5", "status": "unaffected", "lessThanOrEqual": "6.8.*", "versionType": "custom" } ] }, { "vendor": "linux", "product": "linux_kernel", "cpes": [ "cpe:2.3:o:linux:linux_kernel:-:*:*:*:*:*:*:*" ], "defaultStatus": "unknown", "versions": [ { "version": "6.9", "status": "unaffected" } ] } ], "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 8.4, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH" } }, { "other": { "type": "ssvc", "content": { "timestamp": "2024-05-24T15:01:40.323674Z", "id": "CVE-2024-35869", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-01-16T21:16:06.861Z" } }, { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-02T03:21:48.968Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/645f332c6b63499cc76197f9b6bffcc659ba64cc", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/e1db9ae87b7148c021daee1fcc4bc71b2ac58a79", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/062a7f0ff46eb57aff526897bd2bebfdb1d3046a", "tags": [ "x_transferred" ] } ] } ] } }