EPIC-SEC-004MEDIUMTarget: Data Alignment
Struct Memory Offset Alignment Verification
Description
Enforces memory structural byte alignment.
Technical Rationale
Solana's execution runtime requires memory structures to align to 8-byte boundaries for efficient instruction loading. A structural layout that leaves u64 or Pubkey fields misaligned will cause sudden transaction crashes.
Code Assessment Examples
Insecure Practice
// Vulnerable: u8 insertion leaves u64 misaligned on 8-byte boundary
struct Stats {
authority: Pubkey,
tier: u8, // 1 byte
amount: u64, // Misaligned! Causes runtime panic
} Secure Resolution
// Safe: Padding restores exact 8-byte alignment constraints
struct Stats {
authority: Pubkey,
tier: u8,
_padding: [u8; 7], // Pads to 8-byte boundary
amount: u64,
}