From: Michal Simek Date: Mon, 8 Oct 2018 12:17:19 +0000 (+0200) Subject: serial: uartps: Do not allow use aliases >= MAX_UART_INSTANCES X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2088cfd882d0403609bdf426e9b24372fe1b8337;p=linux.git serial: uartps: Do not allow use aliases >= MAX_UART_INSTANCES Aliases >= MAX_UART_INSTANCES is no problem to find out and use but in error path is necessary skip clearing bits in bitmap to ensure that only bits in allocated bitmap are handled and nothing beyond that. Without this patch when for example serial90 alias is used then in error patch bit 90 is clear in 32bit wide bitmap. Fixes: ae1cca3fa347 ("serial: uartps: Change uart ID port allocation") Signed-off-by: Michal Simek Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 0e3dae461f718..c3f6cce300aad 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -1668,7 +1668,8 @@ err_out_unregister_driver: uart_unregister_driver(cdns_uart_data->cdns_uart_driver); err_out_id: mutex_lock(&bitmap_lock); - clear_bit(cdns_uart_data->id, bitmap); + if (cdns_uart_data->id < MAX_UART_INSTANCES) + clear_bit(cdns_uart_data->id, bitmap); mutex_unlock(&bitmap_lock); return rc; } @@ -1693,7 +1694,8 @@ static int cdns_uart_remove(struct platform_device *pdev) rc = uart_remove_one_port(cdns_uart_data->cdns_uart_driver, port); port->mapbase = 0; mutex_lock(&bitmap_lock); - clear_bit(cdns_uart_data->id, bitmap); + if (cdns_uart_data->id < MAX_UART_INSTANCES) + clear_bit(cdns_uart_data->id, bitmap); mutex_unlock(&bitmap_lock); clk_disable_unprepare(cdns_uart_data->uartclk); clk_disable_unprepare(cdns_uart_data->pclk);