CVE-2026-90156

About vulnerability

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: safely discard unregistered deferred locks

When vfs_lock_file() defers a lock, smb2_lock() puts its ksmbd_lock on rollback_list before allocating and registering the asynchronous work. If either operation fails, rollback assumes that smb_lock->conn is initialized and dereferences NULL. The deferred file_lock also remains linked into the VFS blocked-lock state while it is freed.

Keep the lock off rollback_list until async setup succeeds. On setup failures, explicitly unblock and wake the deferred lock before freeing it and its ksmbd wrapper.

Affected product:

Debian 10 ELS , Debian 11 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS

Affected packages:

linux @ 5.10.259 (+4 more)