serial: altera_jtaguart: handle uart_add_one_port() failures

altera_jtaguart_probe() maps the register window before registering the
UART port, but it ignores failures from uart_add_one_port(). If port
registration fails, probe still returns success and the mapping remains
live until a later remove path that is not part of probe failure cleanup.

Return the uart_add_one_port() error and unmap the register window on
that failure path.

This issue was identified during our ongoing static-analysis research while
reviewing kernel code.

Fixes: 5bcd601049c6 ("serial: Add driver for the Altera JTAG UART")
Cc: stable <stable@kernel.org>
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
Link: https://patch.msgid.link/20260512065837.79528-1-mhun512@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/altera_jtaguart.c b/drivers/tty/serial/altera_jtaguart.c
index d47a62d1c9f7dce1d1b7832e8bf168a761b15f7e..20f079fe11d8219cef0a187b04453f8c5839cac6 100644 (file)
--- a/drivers/tty/serial/altera_jtaguart.c
+++ b/drivers/tty/serial/altera_jtaguart.c
@@ -379,6 +379,7 @@ static int altera_jtaguart_probe(struct platform_device *pdev)
        struct resource *res_mem;
        int i = pdev->id;
        int irq;
+       int ret;
 
        /* -1 emphasizes that the platform must have one port, no .N suffix */
        if (i == -1)
@@ -418,7 +419,11 @@ static int altera_jtaguart_probe(struct platform_device *pdev)
        port->flags = UPF_BOOT_AUTOCONF;
        port->dev = &pdev->dev;
 
-       uart_add_one_port(&altera_jtaguart_driver, port);
+       ret = uart_add_one_port(&altera_jtaguart_driver, port);
+       if (ret) {
+               iounmap(port->membase);
+               return ret;
+       }
 
        return 0;
 }