Instruction decode slice overflow on incomplete bytecode

[publicqi]

Component

Cast

Have you ensured that all of these are up to date?

• Foundry
• Foundryup

What version of Foundry are you on?

forge 0.2.0 (398ef4a 2024-11-23T00:27:34.394254000Z)

What command(s) is the bug in?

cast da 0x60

Operating System

None

Describe the bug

0x60 is PUSH1, and it's an incomplete bytecode sequence.

It will panic in crates/evm/core/src/ic.rs

/// Decodes raw opcode bytes into [`Instruction`]s.
pub fn decode_instructions(code: &[u8]) -> Vec<Instruction<'_>> {
    let mut pc = 0;
    let mut steps = Vec::new();

    while pc < code.len() {
        let op = OpCode::new(code[pc]);
        let immediate_size = op.map(|op| immediate_size(op, &code[pc + 1..])).unwrap_or(0) as usize;

        steps.push(Instruction { op, pc, immediate: &code[pc + 1..pc + 1 + immediate_size] });

        pc += 1 + immediate_size;
    }

    steps
}