Hi, Static analysis with CoverityScan found a potential null pointer deference issue with a null uart with recent commit 6d7f677a2afa1c82d7fc7af7f9159cbffd5dc010 ("serial: 8250: Rate limit serial port rx interrupts during input overruns"). Coverity Analysis is below: 983 uart = serial8250_find_match_or_unused(&up->port); 2. Condition uart, taking false branch. 3. var_compare_op: Comparing uart to null implies that uart might be null. 984 if (uart && uart->port.type != PORT_8250_CIR) { 985 if (uart->port.dev) ... ... 1075 /* Initialise interrupt backoff work if required */ 4. Condition up->overrun_backoff_time_ms > 0, taking false branch. 1076 if (up->overrun_backoff_time_ms > 0) { CID 1475967 (#1 of 2): Dereference after null check (FORWARD_NULL) 1077 uart->overrun_backoff_time_ms = up->overrun_backoff_time_ms; 1078 INIT_DELAYED_WORK(&uart->overrun_backoff, 1079 serial_8250_overrun_backoff_work); 1080 } else { CID 1475967 (#2 of 2): Dereference after null check (FORWARD_NULL)5. var_deref_op: Dereferencing null pointer uart. 1081 uart->overrun_backoff_time_ms = 0; 1082 } The implication is that uart could be null, so the code block between lines 1076 and 1082 should be guarded with a sanity null check on uart too. Colin