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CVE-2026-31704 (GCVE-0-2026-31704)

Vulnerability from cvelistv5 – Published: 2026-05-01 13:56 – Updated: 2026-06-14 17:43
VLAI
Title
ksmbd: use check_add_overflow() to prevent u16 DACL size overflow
Summary
In the Linux kernel, the following vulnerability has been resolved: ksmbd: use check_add_overflow() to prevent u16 DACL size overflow set_posix_acl_entries_dacl() and set_ntacl_dacl() accumulate ACE sizes in u16 variables. When a file has many POSIX ACL entries, the accumulated size can wrap past 65535, causing the pointer arithmetic (char *)pndace + *size to land within already-written ACEs. Subsequent writes then overwrite earlier entries, and pndacl->size gets a truncated value. Use check_add_overflow() at each accumulation point to detect the wrap before it corrupts the buffer, consistent with existing check_mul_overflow() usage elsewhere in smbacl.c.
Severity
5.5 (Medium)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 , < 41e53a773db6342ac9a689ee5ba635c31744c9f0 (git)
Affected: e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 , < 8d5729350b236896f51379588d9a690b7fafb8db (git)
Affected: e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 , < e1955a94b6f17f4b058afa955a6f187eb3ed7615 (git)
Affected: e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 , < 5e7b8f3c539d69b2ed5f2408e2f75e68ce7eef43 (git)
Affected: e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 , < ef7902be3f215b6bf7babe4dc9dd9a7d57dad7a7 (git)
Affected: e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 , < 299f962c0b02d048fb45d248b4da493d03f3175d (git)
guessed Create a notification for this product.
Linux Linux Affected: 5.15
Unaffected: 0 , < 5.15 (semver)
Unaffected: 6.1.175 , ≤ 6.1.* (semver)
Unaffected: 6.6.136 , ≤ 6.6.* (semver)
Unaffected: 6.12.84 , ≤ 6.12.* (semver)
Unaffected: 6.18.25 , ≤ 6.18.* (semver)
Unaffected: 7.0.2 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
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}



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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.

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  • 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.
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  • 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.


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