Index: clang/lib/Analysis/UnsafeBufferUsage.cpp
===================================================================
--- clang/lib/Analysis/UnsafeBufferUsage.cpp
+++ clang/lib/Analysis/UnsafeBufferUsage.cpp
@@ -1886,8 +1886,11 @@
 
       if (Parm->isImplicit())
         continue;
-      assert(Parm->getIdentifier() &&
-             "A parameter of a function definition has no name");
+      // A parameter of a function definition has no name.
+      // FIXME: We should create a name for the parameter as part of the fix-it.
+      // Go through declarations of the function and look for a name?
+      if (!Parm->getIdentifier())
+        return std::nullopt;
       if (i == ParmIdx)
         // This is our spanified paramter!
         SS << NewTypeText.str() << "(" << Parm->getIdentifier()->getName().str() << ", "
Index: clang/test/SemaCXX/warn-unsafe-buffer-usage-fixits-parm-span.cpp
===================================================================
--- clang/test/SemaCXX/warn-unsafe-buffer-usage-fixits-parm-span.cpp
+++ clang/test/SemaCXX/warn-unsafe-buffer-usage-fixits-parm-span.cpp
@@ -156,4 +156,9 @@
   if (++MyName){}
 }
 
+// CHECK-NOT: fix-it:{{.*}}:
+void parmHasNoName(int *p, int *) { // cannot fix the function because there is one parameter has no name.
+  p[5] = 5;
+}
+
 #endif