From 2088cfd882d0403609bdf426e9b24372fe1b8337 Mon Sep 17 00:00:00 2001 From: Michal Simek Date: Mon, 8 Oct 2018 14:17:19 +0200 Subject: 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 --- drivers/tty/serial/xilinx_uartps.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 0e3dae461f71..c3f6cce300aa 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); -- cgit v1.2.3