Size computation for allocation may overflow (#99)

* Size computation for allocation may overflow

Performing calculations involving the size of potentially large strings or slices can result in an overflow (for signed integer types) or a wraparound (for unsigned types). An overflow causes the result of the calculation to become negative, while a wraparound results in a small (positive) number.

vendor/github.com/redis/go-redis/v9/internal/proto/reader.go

@@ -50,7 +50,8 @@ func (e RedisError) Error() string { return string(e) }
 func (RedisError) RedisError() {}
 
 func ParseErrorReply(line []byte) error {
-	return RedisError(line[1:])
+	msg := string(line[1:])
+	return parseTypedRedisError(msg)
 }
 
 //------------------------------------------------------------------------------
@@ -99,6 +100,92 @@ func (r *Reader) PeekReplyType() (byte, error) {
 	return b[0], nil
 }
 
+func (r *Reader) PeekPushNotificationName() (string, error) {
+	// "prime" the buffer by peeking at the next byte
+	c, err := r.Peek(1)
+	if err != nil {
+		return "", err
+	}
+	if c[0] != RespPush {
+		return "", fmt.Errorf("redis: can't peek push notification name, next reply is not a push notification")
+	}
+
+	// peek 36 bytes at most, should be enough to read the push notification name
+	toPeek := 36
+	buffered := r.Buffered()
+	if buffered == 0 {
+		return "", fmt.Errorf("redis: can't peek push notification name, no data available")
+	}
+	if buffered < toPeek {
+		toPeek = buffered
+	}
+	buf, err := r.rd.Peek(toPeek)
+	if err != nil {
+		return "", err
+	}
+	if buf[0] != RespPush {
+		return "", fmt.Errorf("redis: can't parse push notification: %q", buf)
+	}
+
+	if len(buf) < 3 {
+		return "", fmt.Errorf("redis: can't parse push notification: %q", buf)
+	}
+
+	// remove push notification type
+	buf = buf[1:]
+	// remove first line - e.g. >2\r\n
+	for i := 0; i < len(buf)-1; i++ {
+		if buf[i] == '\r' && buf[i+1] == '\n' {
+			buf = buf[i+2:]
+			break
+		} else {
+			if buf[i] < '0' || buf[i] > '9' {
+				return "", fmt.Errorf("redis: can't parse push notification: %q", buf)
+			}
+		}
+	}
+	if len(buf) < 2 {
+		return "", fmt.Errorf("redis: can't parse push notification: %q", buf)
+	}
+	// next line should be $<length><string>\r\n or +<length><string>\r\n
+	// should have the type of the push notification name and it's length
+	if buf[0] != RespString && buf[0] != RespStatus {
+		return "", fmt.Errorf("redis: can't parse push notification name: %q", buf)
+	}
+	typeOfName := buf[0]
+	// remove the type of the push notification name
+	buf = buf[1:]
+	if typeOfName == RespString {
+		// remove the length of the string
+		if len(buf) < 2 {
+			return "", fmt.Errorf("redis: can't parse push notification name: %q", buf)
+		}
+		for i := 0; i < len(buf)-1; i++ {
+			if buf[i] == '\r' && buf[i+1] == '\n' {
+				buf = buf[i+2:]
+				break
+			} else {
+				if buf[i] < '0' || buf[i] > '9' {
+					return "", fmt.Errorf("redis: can't parse push notification name: %q", buf)
+				}
+			}
+		}
+	}
+
+	if len(buf) < 2 {
+		return "", fmt.Errorf("redis: can't parse push notification name: %q", buf)
+	}
+	// keep only the notification name
+	for i := 0; i < len(buf)-1; i++ {
+		if buf[i] == '\r' && buf[i+1] == '\n' {
+			buf = buf[:i]
+			break
+		}
+	}
+
+	return util.BytesToString(buf), nil
+}
+
 // ReadLine Return a valid reply, it will check the protocol or redis error,
 // and discard the attribute type.
 func (r *Reader) ReadLine() ([]byte, error) {
@@ -115,7 +202,7 @@ func (r *Reader) ReadLine() ([]byte, error) {
 		var blobErr string
 		blobErr, err = r.readStringReply(line)
 		if err == nil {
-			err = RedisError(blobErr)
+			err = parseTypedRedisError(blobErr)
 		}
 		return nil, err
 	case RespAttr: