wait_queue_entry_t *wq;
struct userfaultfd_wait_queue *uwq;
- VM_BUG_ON(!spin_is_locked(&wqh->lock));
+ lockdep_assert_held(&wqh->lock);
uwq = NULL;
if (!waitqueue_active(wqh))
ret = -EINVAL;
if (!vma_can_userfault(cur))
goto out_unlock;
+
+ /*
+ * UFFDIO_COPY will fill file holes even without
+ * PROT_WRITE. This check enforces that if this is a
+ * MAP_SHARED, the process has write permission to the backing
+ * file. If VM_MAYWRITE is set it also enforces that on a
+ * MAP_SHARED vma: there is no F_WRITE_SEAL and no further
+ * F_WRITE_SEAL can be taken until the vma is destroyed.
+ */
+ ret = -EPERM;
+ if (unlikely(!(cur->vm_flags & VM_MAYWRITE)))
+ goto out_unlock;
+
/*
* If this vma contains ending address, and huge pages
* check alignment.
BUG_ON(!vma_can_userfault(vma));
BUG_ON(vma->vm_userfaultfd_ctx.ctx &&
vma->vm_userfaultfd_ctx.ctx != ctx);
+ WARN_ON(!(vma->vm_flags & VM_MAYWRITE));
/*
* Nothing to do: this vma is already registered into this
cond_resched();
BUG_ON(!vma_can_userfault(vma));
+ WARN_ON(!(vma->vm_flags & VM_MAYWRITE));
/*
* Nothing to do: this vma is already registered into this