--- a/Documentation/arm64/tagged-address-abi.rst~userfaultfd-do-not-untag-user-pointers
+++ a/Documentation/arm64/tagged-address-abi.rst
@@ -45,14 +45,24 @@ how the user addresses are used by the k
 
 1. User addresses not accessed by the kernel but used for address space
    management (e.g. ``mprotect()``, ``madvise()``). The use of valid
-   tagged pointers in this context is allowed with the exception of
-   ``brk()``, ``mmap()`` and the ``new_address`` argument to
-   ``mremap()`` as these have the potential to alias with existing
-   user addresses.
-
-   NOTE: This behaviour changed in v5.6 and so some earlier kernels may
-   incorrectly accept valid tagged pointers for the ``brk()``,
-   ``mmap()`` and ``mremap()`` system calls.
+   tagged pointers in this context is allowed with these exceptions:
+
+   - ``brk()``, ``mmap()`` and the ``new_address`` argument to
+     ``mremap()`` as these have the potential to alias with existing
+      user addresses.
+
+     NOTE: This behaviour changed in v5.6 and so some earlier kernels may
+     incorrectly accept valid tagged pointers for the ``brk()``,
+     ``mmap()`` and ``mremap()`` system calls.
+
+   - The ``range.start``, ``start`` and ``dst`` arguments to the
+     ``UFFDIO_*`` ``ioctl()``s used on a file descriptor obtained from
+     ``userfaultfd()``, as fault addresses subsequently obtained by reading
+     the file descriptor will be untagged, which may otherwise confuse
+     tag-unaware programs.
+
+     NOTE: This behaviour changed in v5.14 and so some earlier kernels may
+     incorrectly accept valid tagged pointers for this system call.
 
 2. User addresses accessed by the kernel (e.g. ``write()``). This ABI
    relaxation is disabled by default and the application thread needs to
--- a/fs/userfaultfd.c~userfaultfd-do-not-untag-user-pointers
+++ a/fs/userfaultfd.c
@@ -1236,23 +1236,21 @@ static __always_inline void wake_userfau
 }
 
 static __always_inline int validate_range(struct mm_struct *mm,
-					  __u64 *start, __u64 len)
+					  __u64 start, __u64 len)
 {
 	__u64 task_size = mm->task_size;
 
-	*start = untagged_addr(*start);
-
-	if (*start & ~PAGE_MASK)
+	if (start & ~PAGE_MASK)
 		return -EINVAL;
 	if (len & ~PAGE_MASK)
 		return -EINVAL;
 	if (!len)
 		return -EINVAL;
-	if (*start < mmap_min_addr)
+	if (start < mmap_min_addr)
 		return -EINVAL;
-	if (*start >= task_size)
+	if (start >= task_size)
 		return -EINVAL;
-	if (len > task_size - *start)
+	if (len > task_size - start)
 		return -EINVAL;
 	return 0;
 }
@@ -1316,7 +1314,7 @@ static int userfaultfd_register(struct u
 		vm_flags |= VM_UFFD_MINOR;
 	}
 
-	ret = validate_range(mm, &uffdio_register.range.start,
+	ret = validate_range(mm, uffdio_register.range.start,
 			     uffdio_register.range.len);
 	if (ret)
 		goto out;
@@ -1522,7 +1520,7 @@ static int userfaultfd_unregister(struct
 	if (copy_from_user(&uffdio_unregister, buf, sizeof(uffdio_unregister)))
 		goto out;
 
-	ret = validate_range(mm, &uffdio_unregister.start,
+	ret = validate_range(mm, uffdio_unregister.start,
 			     uffdio_unregister.len);
 	if (ret)
 		goto out;
@@ -1671,7 +1669,7 @@ static int userfaultfd_wake(struct userf
 	if (copy_from_user(&uffdio_wake, buf, sizeof(uffdio_wake)))
 		goto out;
 
-	ret = validate_range(ctx->mm, &uffdio_wake.start, uffdio_wake.len);
+	ret = validate_range(ctx->mm, uffdio_wake.start, uffdio_wake.len);
 	if (ret)
 		goto out;
 
@@ -1711,7 +1709,7 @@ static int userfaultfd_copy(struct userf
 			   sizeof(uffdio_copy)-sizeof(__s64)))
 		goto out;
 
-	ret = validate_range(ctx->mm, &uffdio_copy.dst, uffdio_copy.len);
+	ret = validate_range(ctx->mm, uffdio_copy.dst, uffdio_copy.len);
 	if (ret)
 		goto out;
 	/*
@@ -1768,7 +1766,7 @@ static int userfaultfd_zeropage(struct u
 			   sizeof(uffdio_zeropage)-sizeof(__s64)))
 		goto out;
 
-	ret = validate_range(ctx->mm, &uffdio_zeropage.range.start,
+	ret = validate_range(ctx->mm, uffdio_zeropage.range.start,
 			     uffdio_zeropage.range.len);
 	if (ret)
 		goto out;
@@ -1818,7 +1816,7 @@ static int userfaultfd_writeprotect(stru
 			   sizeof(struct uffdio_writeprotect)))
 		return -EFAULT;
 
-	ret = validate_range(ctx->mm, &uffdio_wp.range.start,
+	ret = validate_range(ctx->mm, uffdio_wp.range.start,
 			     uffdio_wp.range.len);
 	if (ret)
 		return ret;
@@ -1866,7 +1864,7 @@ static int userfaultfd_continue(struct u
 			   sizeof(uffdio_continue) - (sizeof(__s64))))
 		goto out;
 
-	ret = validate_range(ctx->mm, &uffdio_continue.range.start,
+	ret = validate_range(ctx->mm, uffdio_continue.range.start,
 			     uffdio_continue.range.len);
 	if (ret)
 		goto out;
