fix(resp): replace wrapping arithmetic with checked operations in parse_integer

Use checked_mul/checked_add instead of wrapping_mul/wrapping_add to detect integer overflow in the RESP integer parser. Previously, a bulk string length exceeding i64::MAX was silently wrapped, which could lead to incorrect parsing if rustis is used as a proxy with untrusted input.

Author: mcatanzariti

src/resp/resp_frame_parser.rs

@@ -253,8 +253,10 @@ impl<'a> RespFrameParser<'a> {
             let b = slice[i];
             match b {
                 b'0'..=b'9' => {
-                    // n = n * 10 + (b - b'0')
-                    n = n.wrapping_mul(10).wrapping_add((b - b'0') as i64);
+                    n = n
+                        .checked_mul(10)
+                        .and_then(|n| n.checked_add((b - b'0') as i64))
+                        .ok_or(Error::Client(ClientError::CannotParseInteger))?;
                     i += 1;
                 }
                 b'\r' => match slice.get(i + 1) {