ksmbd: use check_add_overflow() to prevent u16 DACL size overflow (Linux Linux)

CVE-2026-31704
MEDIUM 5.5

At a glance

Source
NVD
EPSS
EPSS 0.12 % · percentile 2 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

Description

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.

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 41e53a773db6342ac9a689ee5ba635c31744c9f0 ; affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 8d5729350b236896f51379588d9a690b7fafb8db ; affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < e1955a94b6f17f4b058afa955a6f187eb3ed7615 ; affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 5e7b8f3c539d69b2ed5f2408e2f75e68ce7eef43 ; affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < ef7902be3f215b6bf7babe4dc9dd9a7d57dad7a7 ; affected e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 < 299f962c0b02d048fb45d248b4da493d03f3175d
Linux · Linuxaffected 5.15 ; unaffected 0 < 5.15 ; unaffected 6.1.175 ≤ 6.1.* ; unaffected 6.6.136 ≤ 6.6.* ; unaffected 6.12.84 ≤ 6.12.* ; unaffected 6.18.25 ≤ 6.18.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD