SB20261029194 - Use of uninitialized resource in Linux kernel smb server

Description

This security bulletin contains information about 1 vulnerability.

1) Use of uninitialized resource (CVE-ID: CVE-2026-99115)

CWE-ID: CWE-908 - Use of Uninitialized Resource

CVSSv4: 5.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a remote user to disclose residual response-buffer data from the Linux kernel SMB server.

The vulnerability exists due to an uninitialized FileSysIdentifier field in ksmbd's smb2_get_info_filesystem() function when processing compound SMB requests for FS_POSIX_INFORMATION. A remote user can submit a compound request in which an earlier reply is replaced by a shorter error response, leaving residual data that the subsequent filesystem-information reply can disclose through the eight-byte field.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/ab057f271ef60ff8163818badc3de75c480eca07
• https://git.kernel.org/stable/c/beba2ef6f66a71f20531ac70a1acb0b221e362e9
• https://git.kernel.org/stable/c/db2267b27c054a6c2151ff7fbb67927e784f31d6