Missing Table Type Validation in call_indirect Instruction

[Q1IQ]

Subject of the issue

iwasm fails to validate the type of the table used in the call_indirect instruction. According to the WebAssembly specification, the table associated with call_indirect must have a funcref type.

Test case

(module
  (type (func (param i32 i32) (result i32)))

  (func $func1 (type 0) (param i32 i32) (result i32)
    local.get 0
    local.get 1
    i32.add)

  (func $func2 (type 0) (param i32 i32) (result i32)
    local.get 0
    local.get 1
    i32.sub)

  (table 2 externref)
  (elem (i32.const 0) externref (ref.null extern) (ref.null extern))

  (func $main (result i32)
    i32.const 0x12341234
    i32.const 0x1234
    i32.const 1
    call_indirect (type 0)
    )

  (export "main" (func $main))
)

Your environment

• OS: Ubuntu 20.04
• CPU: amd64
• WAMR version: iwasm 2.2.0
• Commands:

iwasm  --interp -f main ./program.wasm
iwasm --fast-jit -f main ./program.wasm
iwasm --llvm-jit -f main ./program.wasm
iwasm --multi-tier-jit -f main./program.wasm

Actual behavior

The iwasm proceeds to execute the module without raising any validation error, despite the table having an invalid type (externref) for use in the call_indirect instruction. The observed output in all execution modes is:

0x12342468:i32

Expected behavior

The WebAssembly specification mandates that the table used in the call_indirect instruction must be of type funcref. Tables of type externref cannot hold function references and are invalid for call_indirect. The runtime should fail validation and report an error similar to:

Validation error: call_indirect is only valid when a table has type funcref

[TianlongLiang]

Thanks for reporting this issue, I will take a look, and keep you updated :)