{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-53186", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-11-19T17:17:25.012Z", "datePublished": "2024-12-27T13:49:29.215Z", "dateUpdated": "2026-08-05T11:44:29.475Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:44:29.475Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix use-after-free in SMB request handling\n\nA race condition exists between SMB request handling in\n`ksmbd_conn_handler_loop()` and the freeing of `ksmbd_conn` in the\nworkqueue handler `handle_ksmbd_work()`. This leads to a UAF.\n- KASAN: slab-use-after-free Read in handle_ksmbd_work\n- KASAN: slab-use-after-free in rtlock_slowlock_locked\n\nThis race condition arises as follows:\n- `ksmbd_conn_handler_loop()` waits for `conn->r_count` to reach zero:\n `wait_event(conn->r_count_q, atomic_read(&conn->r_count) == 0);`\n- Meanwhile, `handle_ksmbd_work()` decrements `conn->r_count` using\n `atomic_dec_return(&conn->r_count)`, and if it reaches zero, calls\n `ksmbd_conn_free()`, which frees `conn`.\n- However, after `handle_ksmbd_work()` decrements `conn->r_count`,\n it may still access `conn->r_count_q` in the following line:\n `waitqueue_active(&conn->r_count_q)` or `wake_up(&conn->r_count_q)`\n This results in a UAF, as `conn` has already been freed.\n\nThe discovery of this UAF can be referenced in the following PR for\nsyzkaller's support for SMB requests." } ], "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 - ksmbd is the in-kernel SMB server listening on TCP/445; the vulnerable work-completion path is driven entirely by PDUs received from a remote peer and by remote connection teardown. No local access is needed.\nAC:L - The attacker controls both sides of the race — queuing SMB work items (raising conn->r_count) and abruptly closing the TCP connection to drive ksmbd_conn_handler_loop into wait_event/free — and can retry indefinitely across many parallel connections; syzkaller reproduced it without targeting.\nPR:N - queue_ksmbd_work()/handle_ksmbd_work() run for every received PDU including the very first SMB2 NEGOTIATE, before session setup or any credential validation, so an unauthenticated remote attacker reaches the bug.\nUI:N - Exploitation requires only that the attacker open connections and send/close them; no action by any local user or administrator is involved.\nS:U - The use-after-free corrupts kernel heap memory within the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The freed ksmbd_conn is a sprayable general-cache allocation, and the UAF read of conn->r_count_q plus the list walk in wake_up() over reclaimed memory can be leveraged into kernel memory disclosure and, via the resulting control primitive, arbitrary read.\nI:H - wake_up() on the freed waitqueue writes to freed memory (spinlock acquisition and list_del in the wake function) and performs an indirect call through curr->func taken from reclaimed, attacker-sprayable memory, giving a control-flow hijack / arbitrary write primitive.\nA:H - Even without successful exploitation, the use-after-free reliably produces slab corruption, KASAN splats, and kernel oops/panic in handle_ksmbd_work or the RT lock slowpath, and can be triggered repeatedly by an unauthenticated remote peer." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/server/server.c" ], "versions": [ { "version": "18f06bacc197d4ac9b518ad1c69999bc3d83e7aa", "lessThan": "a96f9eb7add30ba0fafcfe7b7aca090978196800", "status": "affected", "versionType": "git" }, { "version": "e9dac92f4482a382e8c0fe1bc243da5fc3526b0c", "lessThan": "f20b77f7897e6aab9ce5527e6016ad2be5d70a33", "status": "affected", "versionType": "git" }, { "version": "ee426bfb9d09b29987369b897fe9b6485ac2be27", "lessThan": "96261adb998a3b513468b6ce17dbec76be5507d4", "status": "affected", "versionType": "git" }, { "version": "ee426bfb9d09b29987369b897fe9b6485ac2be27", "lessThan": "9a8c5d89d327ff58e9b2517f8a6afb4181d32c6e", "status": "affected", "versionType": "git" }, { "version": "9fd3cde4628bcd3549ab95061f2bab74d2ed4f3b", "status": "affected", "versionType": "git" }, { "version": "6.6.55", "lessThan": "6.6.64", "status": "affected", "versionType": "semver" }, { "version": "6.11.3", "lessThan": "6.11.11", "status": "affected", "versionType": "semver" }, { "version": "6.10.14", "lessThan": "6.11", "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/server/server.c" ], "versions": [ { "version": "6.12", "status": "affected" }, { "version": "0", "lessThan": "6.12", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.64", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.11.11", "lessThanOrEqual": "6.11.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.2", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13", "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": "6.6.55", "versionEndExcluding": "6.6.64" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11.3", "versionEndExcluding": "6.11.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.12.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.12", "versionEndExcluding": "6.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a96f9eb7add30ba0fafcfe7b7aca090978196800" }, { "url": "https://git.kernel.org/stable/c/f20b77f7897e6aab9ce5527e6016ad2be5d70a33" }, { "url": "https://git.kernel.org/stable/c/96261adb998a3b513468b6ce17dbec76be5507d4" }, { "url": "https://git.kernel.org/stable/c/9a8c5d89d327ff58e9b2517f8a6afb4181d32c6e" } ], "title": "ksmbd: fix use-after-free in SMB request handling", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 7.8, "attackVector": "LOCAL", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2024-53186", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2025-02-10T17:13:00.740506Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-416", "description": "CWE-416 Use After Free" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-02-10T17:21:09.067Z" } } ] } }