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Commit 730d1b7e authored by Chunyan Zhang's avatar Chunyan Zhang Committed by Greg Kroah-Hartman
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serial: sprd: Assign sprd_port after initialized to avoid wrong access 



[ Upstream commit f9608f1887568b728839d006024585ab02ef29e5 ]

The global pointer 'sprd_port' may not zero when sprd_probe returns
failure, that is a risk for sprd_port to be accessed afterward, and
may lead to unexpected errors.

For example:

There are two UART ports, UART1 is used for console and configured in
kernel command line, i.e. "console=";

The UART1 probe failed and the memory allocated to sprd_port[1] was
released, but sprd_port[1] was not set to NULL;

In UART2 probe, the same virtual address was allocated to sprd_port[2],
and UART2 probe process finally will go into sprd_console_setup() to
register UART1 as console since it is configured as preferred console
(filled to console_cmdline[]), but the console parameters (sprd_port[1])
belong to UART2.

So move the sprd_port[] assignment to where the port already initialized
can avoid the above issue.

Fixes: b7396a38 ("tty/serial: Add Spreadtrum sc9836-uart driver support")
Signed-off-by: default avatarChunyan Zhang <chunyan.zhang@unisoc.com>
Link: https://lore.kernel.org/r/20230725064053.235448-1-chunyan.zhang@unisoc.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent dff80665

drivers/tty/serial/sprd_serial.c

+17 −8
Original line number Diff line number Diff line
@@ -1103,7 +1103,7 @@ static bool sprd_uart_is_console(struct uart_port *uport) 
static int sprd_clk_init(struct uart_port *uport)

{

	struct clk *clk_uart, *clk_parent;

	struct sprd_uart_port *u = sprd_port[uport->line];

	struct sprd_uart_port *u = container_of(uport, struct sprd_uart_port, port);



	clk_uart = devm_clk_get(uport->dev, "uart");

	if (IS_ERR(clk_uart)) {
@@ -1146,22 +1146,22 @@ static int sprd_probe(struct platform_device *pdev) 
{

	struct resource *res;

	struct uart_port *up;

	struct sprd_uart_port *sport;

	int irq;

	int index;

	int ret;



	index = of_alias_get_id(pdev->dev.of_node, "serial");

	if (index < 0 || index >= ARRAY_SIZE(sprd_port)) {

	if (index < 0 || index >= UART_NR_MAX) {

		dev_err(&pdev->dev, "got a wrong serial alias id %d\n", index);

		return -EINVAL;

	}



	sprd_port[index] = devm_kzalloc(&pdev->dev, sizeof(*sprd_port[index]),

					GFP_KERNEL);

	if (!sprd_port[index])

	sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);

	if (!sport)

		return -ENOMEM;



	up = &sprd_port[index]->port;

	up = &sport->port;

	up->dev = &pdev->dev;

	up->line = index;

	up->type = PORT_SPRD;
@@ -1191,7 +1191,7 @@ static int sprd_probe(struct platform_device *pdev) 
	 * Allocate one dma buffer to prepare for receive transfer, in case

	 * memory allocation failure at runtime.

	 */

	ret = sprd_rx_alloc_buf(sprd_port[index]);

	ret = sprd_rx_alloc_buf(sport);

	if (ret)

		return ret;
@@ -1202,14 +1202,23 @@ static int sprd_probe(struct platform_device *pdev) 
			return ret;

		}

	}



	sprd_ports_num++;

	sprd_port[index] = sport;



	ret = uart_add_one_port(&sprd_uart_driver, up);

	if (ret)

		sprd_remove(pdev);

		goto clean_port;



	platform_set_drvdata(pdev, up);



	return 0;



clean_port:

	sprd_port[index] = NULL;

	if (--sprd_ports_num == 0)

		uart_unregister_driver(&sprd_uart_driver);

	sprd_rx_free_buf(sport);

	return ret;

}