In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free in __ksmbd_close_fd() via durable scavenger When a durable file handle survives session disconnect (TCP close without SMB2_LOGOFF), session_fd_check() sets fp-conn = NULL to preserve the handle for later reconnection. However, it did not clean up the byte-range locks on fp-lock_list. Later, when the durable scavenger thread times out and calls __ksmbd_close_fd(NULL, fp), the lock cleanup loop did: spin_lock(&fp-conn-llist_lock); This caused a slab use-after-free because fp-conn was NULL and the original connection object had already been freed by ksmbd_tcp_disconnect().

The root cause is asymmetric cleanup: lock entries (smb_lock-clist) were left dangling on the freed conn-lock_list while fp-conn was nulled out. To fix this issue properly, we need to handle the lifetime of smb_lock-clist across three paths: - Safely skip clist deletion when list is empty and fp-conn is NULL. - Remove the lock from the old connection's lock_list in session_fd_check() - Re-add the lock to the new connection's lock_list in ksmbd_reopen_durable_fd().