Fix - Makes functions starting in the middle of lddw fail verification in SBFv2

src/verifier.rs

@@ -216,9 +216,21 @@ pub struct RequisiteVerifier {}
 impl Verifier for RequisiteVerifier {
     /// Check the program against the verifier's rules
     #[rustfmt::skip]
-    fn verify(prog: &[u8], config: &Config, _function_registry: &FunctionRegistry) -> Result<(), VerifierError> {
+    fn verify(prog: &[u8], config: &Config, function_registry: &FunctionRegistry) -> Result<(), VerifierError> {
         check_prog_len(prog)?;
 
+        if config.static_syscalls {
+            for (_key, (dst_insn_ptr, _name)) in function_registry.iter() {
+                let dst_insn = ebpf::get_insn(prog, *dst_insn_ptr);
+                if dst_insn.opc == 0 {
+                    return Err(VerifierError::JumpToMiddleOfLDDW(
+                        *dst_insn_ptr,
+                        adj_insn_ptr(*dst_insn_ptr),
+                    ));
+                }
+            }
+        }
+
         let mut insn_ptr: usize = 0;
         while (insn_ptr + 1) * ebpf::INSN_SIZE <= prog.len() {
             let insn = ebpf::get_insn(prog, insn_ptr);

tests/ubpf_execution.rs

@@ -2777,25 +2777,6 @@ fn test_err_static_jmp_lddw() {
         TestContextObject::new(9),
         { |_vm, res: ProgramResult| { res.unwrap() == 0x2 } },
     );
-    test_interpreter_and_jit_asm!(
-        "
-        call 3
-        mov r0, r0
-        mov r0, r0
-        lddw r0, 0x1122334455667788
-        exit
-        ",
-        [],
-        (),
-        TestContextObject::new(2),
-        {
-            |_vm, res: ProgramResult| {
-                matches!(res.unwrap_err(),
-                    EbpfError::UnsupportedInstruction(pc) if pc == 33
-                )
-            }
-        },
-    );
 }
 
 #[test]

tests/ubpf_verifier.rs

@@ -227,6 +227,22 @@ fn test_verifier_err_jmp_lddw() {
             .unwrap();
 }
 
+#[test]
+#[should_panic(expected = "JumpToMiddleOfLDDW(2, 31)")]
+fn test_verifier_err_call_lddw() {
+    let executable = assemble::<TestContextObject>(
+        "
+        call 1
+        lddw r0, 0x1122334455667788
+        exit",
+        Arc::new(BuiltInProgram::new_loader(Config::default())),
+    )
+    .unwrap();
+    let _verified_executable =
+        VerifiedExecutable::<RequisiteVerifier, TestContextObject>::from_executable(executable)
+            .unwrap();
+}
+
 #[test]
 #[should_panic(expected = "JumpOutOfCode(3, 29)")]
 fn test_verifier_err_jmp_out() {