SB2026062943 - Use of Uninitialized Variable in Linux kernel fuse

Description

This security bulletin contains information about 1 vulnerability.

1) Use of Uninitialized Variable (CVE-ID: CVE-2026-53311)

CWE-ID: CWE-457 - Use of Uninitialized Variable

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to use of uninitialized memory in fuse_dentry_revalidate() when handling dentry revalidation during file open operations. A local user can trigger file open paths involving a dentry with an uninitialized d_time value to cause a denial of service.

The issue was identified by KMSAN and occurs when a dentry allocated by __d_alloc() is revalidated before d_time is initialized.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/3ac9117ba3deab8a5dd22847355f861686f4bee7
• https://git.kernel.org/stable/c/5a6baf204610589f8a5b5a1cd69d1fe661d9d3cd
• https://git.kernel.org/stable/c/da3d241c5b925f17a9d8051d7a9e0d454d8e01f6