SB2026092555 - Improper Check for Unusual or Exceptional Conditions in Linux kernel smb server

Description

This security bulletin contains information about 1 vulnerability.

1) Improper Check for Unusual or Exceptional Conditions (CVE-ID: CVE-2026-93811)

CWE-ID: CWE-754 - Improper Check for Unusual or Exceptional Conditions

CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a memory leak and an incorrect success result.

The vulnerability exists due to improper exceptional-condition handling in ksmbd_vfs_get_sd_xattr() when validating a decoded security descriptor size. A local user can trigger validation of a security descriptor smaller than struct smb_ntsd to cause a memory leak and an incorrect success result.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/6e6329322ad733c5b23555c609353841560b26bc
• https://git.kernel.org/stable/c/c3836f55e0dab96314774215e12d87f63fa919f2
• https://git.kernel.org/stable/c/d708a36634bb7b6f94d0e76d587d2ec50b2b93b5