5.4-stable review patch. If anyone has any objections, please let me know.
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From: Chunyan Zhang chunyan.zhang@unisoc.com
[ 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: b7396a38fb28 ("tty/serial: Add Spreadtrum sc9836-uart driver support") Signed-off-by: Chunyan Zhang chunyan.zhang@unisoc.com Link: https://lore.kernel.org/r/20230725064053.235448-1-chunyan.zhang@unisoc.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/tty/serial/sprd_serial.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-)
diff --git a/drivers/tty/serial/sprd_serial.c b/drivers/tty/serial/sprd_serial.c index 9cf771a9cff62..18f5a7f438329 100644 --- a/drivers/tty/serial/sprd_serial.c +++ b/drivers/tty/serial/sprd_serial.c @@ -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; }