{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-35864", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-17T13:50:33.107Z", "datePublished": "2024-05-19T08:34:22.936Z", "dateUpdated": "2026-08-05T11:30:28.316Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:30:28.316Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix potential UAF in smb2_is_valid_lease_break()\n\nSkip sessions that are being teared down (status == SES_EXITING) to\navoid UAF." } ], "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 loop is entered only from `cifs_demultiplex_thread()` processing an unsolicited SMB2 lease-break frame received from the remote SMB server over TCP/445, which routinely traverses the internet (e.g. Azure Files and other cloud SMB shares). A malicious or compromised server, or an on-path attacker injecting into the stream, delivers the trigger entirely as network data.\nAC:L - The attacker controls both sides of the race — it forces session teardown (session-expired/user-session-deleted status codes, TCP reset driving reconnect, DFS IPC churn) and then floods lease-break notifications — and it can stall the SMB2 LOGOFF reply so the session lingers in SES_EXITING on `smb_ses_list` for the entire request timeout, making the window arbitrarily wide and repeatable.\nPR:N - Unsolicited oplock/lease-break frames bypass `smb2_verify_signature()` entirely and the handler ignores SessionId/TreeId, matching only on the attacker-supplied LeaseKey, so no credentials on the client and no authenticated SMB session are needed to reach the vulnerable traversal.\nUI:N - In the realistic deployment — a persistent cifs mount from fstab, autofs, or a container volume — the connection already exists, and the compromised server or on-path injector triggers the code path with no action from any local user.\nS:U - The use-after-free corrupts kernel heap memory belonging to the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - Walking a torn-down session's `tcon_list` and `pending_opens` dereferences freed slab objects whose contents the attacker can groom via heap spraying, turning `tcon->cfids`, `open->tlink`, and `open->lease_key` into attacker-influenced pointers that yield a kernel memory read primitive.\nI:H - The path writes into the freed memory — `spin_lock(&tcon->open_file_lock)`, `cifs_stats_inc()` counter increments, and `cifs_get_tlink()` refcount bumps — and later frees/queues work (`queue_work(cifsiod_wq, &cfid->lease_break)`) through sprayed pointers, giving heap corruption and control-flow hijacking potential.\nA:H - Dereferencing freed `cifs_ses`/`cifs_tcon` state from the demultiplex kernel thread readily produces an oops or panic, and because the trigger is a repeatable unauthenticated network frame the attacker can crash the client at will." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/client/smb2misc.c" ], "versions": [ { "version": "7f48558e6489d032b1584b0cc9ac4bb11072c034", "lessThan": "c868cabdf6fdd61bea54532271f4708254e57fc5", "status": "affected", "versionType": "git" }, { "version": "7f48558e6489d032b1584b0cc9ac4bb11072c034", "lessThan": "f92739fdd4522c4291277136399353d7c341fae4", "status": "affected", "versionType": "git" }, { "version": "7f48558e6489d032b1584b0cc9ac4bb11072c034", "lessThan": "a8344e2b69bde63f713b0aa796d70dbeadffddfb", "status": "affected", "versionType": "git" }, { "version": "7f48558e6489d032b1584b0cc9ac4bb11072c034", "lessThan": "705c76fbf726c7a2f6ff9143d4013b18daaaebf1", "status": "affected", "versionType": "git" }, { "version": "a67172a013953664b1dad03c648200c70b90506c", "status": "affected", "versionType": "git" }, { "version": "3.12.48", "lessThan": "3.13", "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/smb2misc.c" ], "versions": [ { "version": "3.13", "status": "affected" }, { "version": "0", "lessThan": "3.13", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.85", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.26", "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": "3.13", "versionEndExcluding": "6.1.85" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.13", "versionEndExcluding": "6.6.26" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.13", "versionEndExcluding": "6.8.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.13", "versionEndExcluding": "6.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.12.48" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/c868cabdf6fdd61bea54532271f4708254e57fc5" }, { "url": "https://git.kernel.org/stable/c/f92739fdd4522c4291277136399353d7c341fae4" }, { "url": "https://git.kernel.org/stable/c/a8344e2b69bde63f713b0aa796d70dbeadffddfb" }, { "url": "https://git.kernel.org/stable/c/705c76fbf726c7a2f6ff9143d4013b18daaaebf1" } ], "title": "smb: client: fix potential UAF in smb2_is_valid_lease_break()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CISA ADP Vulnrichment", "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2024-35864", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2024-05-29T18:32:19.453857Z" } } } ], "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-06-04T17:34:05.415Z" } }, { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-02T03:21:48.471Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/c868cabdf6fdd61bea54532271f4708254e57fc5", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/f92739fdd4522c4291277136399353d7c341fae4", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/a8344e2b69bde63f713b0aa796d70dbeadffddfb", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/705c76fbf726c7a2f6ff9143d4013b18daaaebf1", "tags": [ "x_transferred" ] } ] } ] } }