In the Linux kernel, the following vulnerability has been resolved:
ksmbd: Fix UAF in _closefiletableids
A use-after-free is possible if one thread destroys the file via _ksmbdclose_fd while another thread holds a reference to it. The existing checks on fp->refcount are not sufficient to prevent this.
The fix takes ft->lock around the section which removes the file from the file table. This prevents two threads acquiring the same file pointer via _closefiletableids, as well as the other functions which retrieve a file from the IDR and which already use this same lock.