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CVE-2025-37952 (GCVE-0-2025-37952)

Vulnerability from cvelistv5 – Published: 2025-05-20 16:01 – Updated: 2026-08-05 11:58
VLAI
Title
ksmbd: Fix UAF in __close_file_table_ids
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: Fix UAF in __close_file_table_ids A use-after-free is possible if one thread destroys the file via __ksmbd_close_fd while another thread holds a reference to it. The existing checks on fp->refcount are not sufficient to prevent this. The fix takes ft->lock around the section which removes the file from the file table. This prevents two threads acquiring the same file pointer via __close_file_table_ids, as well as the other functions which retrieve a file from the IDR and which already use this same lock.
Severity
8.8 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < fec1f9e9a650e8e7011330a085c77e7bf2a08ea9 (git)
Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < 9e9841e232b51171ddf3bc4ee517d5d28dc8cad6 (git)
Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < 16727e442568a46d9cca69fe2595896de86e120d (git)
Affected: 0626e6641f6b467447c81dd7678a69c66f7746cf , < 36991c1ccde2d5a521577c448ffe07fcccfe104d (git)
guessed Create a notification for this product.
Linux Linux Affected: 5.15
Unaffected: 0 , < 5.15 (semver)
Unaffected: 6.6.91 , ≤ 6.6.* (semver)
Unaffected: 6.12.29 , ≤ 6.12.* (semver)
Unaffected: 6.14.7 , ≤ 6.14.* (semver)
Unaffected: 6.15 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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              "value": "AV:N - ksmbd is the in-kernel SMB server; the entire path is driven by SMB2 PDUs (TREE_DISCONNECT, LOGOFF, CLOSE) arriving on TCP/445 from a remote peer. No local access is involved at any point.\nAC:L - The attacker controls both sides of the race \u2014 each SMB2 request is dispatched to the concurrent \"ksmbd-io\" workqueue, so pipelining CLOSE alongside TREE_DISCONNECT/LOGOFF on one connection (or using multichannel connections sharing one file table) reliably produces overlapping execution. The unlocked IDR walk gives a wide window, and the race can be retried indefinitely.\nPR:L - The attacker must complete SMB2 SESSION_SETUP, TREE_CONNECT and open at least one file so the session file table is populated, which needs valid (low-privilege) share credentials in a default configuration. Any ordinary share user qualifies, and on guest-mapped public shares even that requirement disappears.\nUI:N - The attacker drives the entire sequence from their own SMB connection; no action by a local user or administrator is needed.\nS:U - The corruption and its consequences are confined to the kernel\u0027s own security authority; there is no VM, IOMMU or sandbox boundary crossed.\nC:H - The freed ksmbd_file is dereferenced for fp-\u003etcon, fp-\u003ef_ci and the fp-\u003eblocked_works list, and the attacker can reallocate the slab object via SMB2_CREATE to control those contents, turning the UAF into an arbitrary kernel-memory read primitive.\nI:H - set_close_state_blocked_works() performs `cancel_work-\u003estate = KSMBD_WORK_CLOSED` and then an indirect call `cancel_work-\u003ecancel_fn(cancel_work-\u003ecancel_argv)` using pointers read out of freed memory, and __ksmbd_close_fd() fput()s a stale struct file and double-frees the object \u2014 giving write-what-where and control-flow hijack primitives.\nA:H - Even unexploited, the double refcount decrement and double kmem_cache_free/fput corrupt the slab allocator and file refcounts, causing an immediate oops or panic that takes down the whole server."
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    "datePublished": "2025-05-20T16:01:47.164Z",
    "dateReserved": "2025-04-16T04:51:23.973Z",
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This prevents two threads acquiring the\\nsame file pointer via __close_file_table_ids, as well as the other\\nfunctions which retrieve a file from the IDR and which already use\\nthis same lock.\"},{\"lang\":\"es\",\"value\":\"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ksmbd: Correcci\u00f3n de UAF en __close_file_table_ids. Es posible un use-after-free si un hilo destruye el archivo mediante __ksmbd_close_fd mientras otro hilo mantiene una referencia a \u00e9l. Las comprobaciones existentes en fp-\u0026gt;refcount no son suficientes para evitarlo. La correcci\u00f3n aplica ft-\u0026gt;lock a la secci\u00f3n que elimina el archivo de la tabla de archivos. 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    "redhat_vex": {
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      "cve": "CVE-2025-37952",
      "id": "CVE-2025-37952",
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      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: ksmbd: Fix UAF in __close_file_table_ids",
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      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "important",
      "current_release_date": "2026-08-28T17:03:38Z",
      "cve": "CVE-2025-37952",
      "id": "CVE-2025-37952",
      "initial_release_date": "2025-05-21T00:46:28Z",
      "product_status:known_not_affected": "563",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2025-37952",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2025-37952.json",
      "version": "12"
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.