On Fri, Oct 09, 2020 at 05:03:38PM +0200, Christian König wrote: > +/* > + * Change backing file, only valid to use during initial VMA setup. > + */ > +void vma_set_file(struct vm_area_struct *vma, struct file *file) > +{ > + if (file) > + get_file(file); > + > + swap(vma->vm_file, file); > + > + if (file) > + fput(file); > +} fput crashes when file is NULL so the error handling after unmap_and_free_vma: can't handle this case, similarly vm_file can't be NULL either. So just simply: swap(vma->vm_file, file); get_file(vma->vm_file); fput(file); Will do? Just let it crash if any of them are wrongly NULL. Jason