overconstrained_seed_account

overconstrained_seed_account

What it does

Detects when a seed account used in PDA derivation is overconstrained as SystemAccount in non-initialization instructions.

Why is this bad?

If a seed account's ownership changes after pool creation (e.g., becomes a token account or mint), future instructions will fail forever because SystemAccount enforces owner == system_program. This can permanently lock funds in the protocol.

Example

// BAD: Using `SystemAccount` for a seed in a non-init instruction is the bad pattern:
#[derive(Accounts)]
pub struct Withdraw<'info> {
    #[account(seeds = [b"pool", creator.key().as_ref()], bump)]
    pub pool: Account<'info, Pool>,
    pub creator: SystemAccount<'info>,  // use UncheckedAccount
}

Use UncheckedAccount<'info> (or another appropriate type) for the seed in non-init instructions so that ownership changes do not break the instruction.