1 files changed, 39 insertions, 0 deletions
diff --git a/firmware/2lib/2common.c b/firmware/2lib/2common.c
index 4db9e77a..472d5acc 100644
--- a/firmware/2lib/2common.c
+++ b/firmware/2lib/2common.c
@@ -103,3 +103,42 @@ ptrdiff_t vb2_offset_of(const void *base, const void *ptr)
 {
 	return (uintptr_t)ptr - (uintptr_t)base;
 }
+
+int vb2_verify_member_inside(const void *parent, size_t parent_size,
+			     const void *member, size_t member_size,
+			     ptrdiff_t member_data_offset,
+			     size_t member_data_size)
+{
+	const uintptr_t parent_end = (uintptr_t)parent + parent_size;
+	const ptrdiff_t member_offs = vb2_offset_of(parent, member);
+	const ptrdiff_t member_end_offs = member_offs + member_size;
+	const ptrdiff_t data_offs = member_offs + member_data_offset;
+	const ptrdiff_t data_end_offs = data_offs + member_data_size;
+
+	/* Make sure parent doesn't wrap */
+	if (parent_end < (uintptr_t)parent)
+		return VB2_ERROR_INSIDE_PARENT_WRAPS;
+
+	/*
+	 * Make sure the member is fully contained in the parent and doesn't
+	 * wrap.  Use >, not >=, since member_size = 0 is possible.
+	 */
+	if (member_end_offs < member_offs)
+		return VB2_ERROR_INSIDE_MEMBER_WRAPS;
+	if (member_offs < 0 || member_offs > parent_size ||
+	    member_end_offs > parent_size)
+		return VB2_ERROR_INSIDE_MEMBER_OUTSIDE;
+
+	/* Make sure the member data is after the member */
+	if (member_data_size > 0 && data_offs < member_end_offs)
+		return VB2_ERROR_INSIDE_DATA_OVERLAP;
+
+	/* Make sure parent fully contains member data, if any */
+	if (data_end_offs < data_offs)
+		return VB2_ERROR_INSIDE_DATA_WRAPS;
+	if (data_offs < 0 || data_offs > parent_size ||
+	    data_end_offs > parent_size)
+		return VB2_ERROR_INSIDE_DATA_OUTSIDE;
+
+	return VB2_SUCCESS;
+}