Prevent divide by zero errors in alloy syntax

Also include previous prior failed fuzz test to validate it doesn't continue to fail.
grafana · Feb 18, 2025 · c427e18 · c427e18
1 parent 5e37a9a
commit c427e18
Show file tree

Hide file tree

Showing 4 changed files with 59 additions and 0 deletions.
diff --git a/internal/component/loki/secretfilter/testdata/fuzz/FuzzGitleaksConfig/7a04bd52cf6c2279 b/internal/component/loki/secretfilter/testdata/fuzz/FuzzGitleaksConfig/7a04bd52cf6c2279
@@ -0,0 +1,4 @@
+go test fuzz v1
+string("types=0+0^100%000")
+string("0")
+string("\xa9\xc1\xd3\xff\xf8\xf8,\xd3r")
diff --git a/internal/component/loki/secretfilter/testdata/fuzz/FuzzGitleaksConfig/7f290c1743bc365f b/internal/component/loki/secretfilter/testdata/fuzz/FuzzGitleaksConfig/7f290c1743bc365f
@@ -0,0 +1,4 @@
+go test fuzz v1
+string("types=100/00/00.00")
+string("0\x00\x80")
+string("\x06")
diff --git a/internal/component/loki/secretfilter/testdata/fuzz/FuzzGitleaksConfig/f3b9ffb4406ec04b b/internal/component/loki/secretfilter/testdata/fuzz/FuzzGitleaksConfig/f3b9ffb4406ec04b
@@ -0,0 +1,4 @@
+go test fuzz v1
+string("\n\t\tforward_to = []\n\t\tredact_with = \"<ALLOY-REDACTED-SECRET:$SECRET_NAME>\"\n\t")
+string("\n\t\ttitle = \"gitleaks custom config\"\n\n\t\t[[rules]]\n\t\tid = \"my-fake-secret\tregex = '''(?i)\\b(fakeSecied a fake secret\"\n\t\tregex = '''(?i)\\b(?:['|\\\"|\\n|\\r|\\s|\\x60|;]|$)'''\n\t\t[rules.allowlist]\n\t\tregexes = [\"abc\\\\d{3}\", \"fakeSecret[9]{5}\"]\nS")
+string("{\n\t\t\t\"message\": \"This is a simple log message with a secret value fakeSecret99999 !\n\t\t}")
diff --git a/syntax/vm/op_binary.go b/syntax/vm/op_binary.go
@@ -1,6 +1,7 @@
 package vm
 
 import (
+	"errors"
 	"fmt"
 	"math"
 	"reflect"
@@ -104,6 +105,29 @@ func evalBinop(lhs value.Value, op token.Token, rhs value.Value) (value.Value, e
 
 	case token.DIV: // number / number
 		lhsNum, rhsNum := lhs.Number(), rhs.Number()
+		switch rhsNum.Kind() {
+		case value.NumberKindUint:
+			if rhsNum.Uint() == uint64(0) {
+				return value.Null, value.Error{
+					Value: origRHS,
+					Inner: errors.New("divide by zero error"),
+				}
+			}
+		case value.NumberKindInt:
+			if rhsNum.Int() == int64(0) {
+				return value.Null, value.Error{
+					Value: origRHS,
+					Inner: errors.New("divide by zero error"),
+				}
+			}
+		case value.NumberKindFloat:
+			if rhsNum.Float() == float64(0) {
+				return value.Null, value.Error{
+					Value: origRHS,
+					Inner: errors.New("divide by zero error"),
+				}
+			}
+		}
 		switch fitNumberKinds(lhsNum.Kind(), rhsNum.Kind()) {
 		case value.NumberKindUint:
 			return value.Uint(lhsNum.Uint() / rhsNum.Uint()), nil
@@ -115,6 +139,29 @@ func evalBinop(lhs value.Value, op token.Token, rhs value.Value) (value.Value, e
 
 	case token.MOD: // number % number
 		lhsNum, rhsNum := lhs.Number(), rhs.Number()
+		switch rhsNum.Kind() {
+		case value.NumberKindUint:
+			if rhsNum.Uint() == uint64(0) {
+				return value.Null, value.Error{
+					Value: origRHS,
+					Inner: errors.New("divide by zero error"),
+				}
+			}
+		case value.NumberKindInt:
+			if rhsNum.Int() == int64(0) {
+				return value.Null, value.Error{
+					Value: origRHS,
+					Inner: errors.New("divide by zero error"),
+				}
+			}
+		case value.NumberKindFloat:
+			if rhsNum.Float() == float64(0) {
+				return value.Null, value.Error{
+					Value: origRHS,
+					Inner: errors.New("divide by zero error"),
+				}
+			}
+		}
 		switch fitNumberKinds(lhsNum.Kind(), rhsNum.Kind()) {
 		case value.NumberKindUint:
 			return value.Uint(lhsNum.Uint() % rhsNum.Uint()), nil