Division By Zero

ID

go.division_by_zero

Severity

high

Remediation Complexity

trivial

Remediation Risk

low

Remediation Effort

low

Resource

Reliability

Language

Go

Tags

reliability, suspicious

Description

Reports a division (/) or remainder (%) whose right-hand operand is the literal 0 — for example x / 0 or x % 0. With integer operands this is a compile-time error for a constant divisor and a runtime panic otherwise; with floating-point operands it produces +Inf, -Inf or NaN. Either way a literal zero divisor is a bug.

Rationale

A literal 0 on the right of / or % is never intentional — it is a typo, a placeholder that was never filled in, or a constant that collapsed to zero. The Go compiler catches some integer cases, but not all (for instance when the dividend is a non-constant), so the panic reaches runtime. Flagging the literal divisor makes the mistake obvious immediately.

y := x / 0   // FLAW — division by literal zero
z := x % 0   // FLAW — remainder by literal zero

y := x / 2   // OK — non-zero divisor
z := x % n   // OK — divisor is a variable

Remediation

Use a non-zero divisor. If the divisor can legitimately be zero at runtime, guard the operation with an explicit zero check before dividing.

References