SB2026102429 - Deadlock in Linux kernel smb server

Description

This security bulletin contains information about 1 vulnerability.

1) Deadlock (CVE-ID: CVE-2026-98897)

CWE-ID: CWE-833 - Deadlock

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

The vulnerability allows a remote user to cause a denial of service through prolonged delays in SMB file operations.

The vulnerability exists due to a lock-induced deadlock in the Linux kernel ksmbd lease-break handling code when processing a conflicting open against a read-handle lease cached by a cifs.ko client through deferred close. A remote user can trigger a conflicting file open to make the server wait for a lease-break acknowledgment while holding ci->m_lock for read, blocking the client's handle-close operation that requires the same lock for write and delaying completion until the 35-second timeout expires.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/27a9bc968d4ae809a3f5ca2f2b136856ee613cb4
• https://git.kernel.org/stable/c/868c9038ffd4af39766d087f68c8f543a3f66635