[PATCH AUTOSEL 4.9 01/26] tty: serial: fsl_lpuart: fix the potential risk of division or modulo by zero

[PATCH AUTOSEL 4.9 01/26] tty: serial: fsl_lpuart: fix the potential risk of division or modulo by zero

[Sasha Levin]

From: Sherry Sun <sherry.sun@nxp.com>

[ Upstream commit fcb10ee27fb91b25b68d7745db9817ecea9f1038 ]

We should be very careful about the register values that will be used
for division or modulo operations, althrough the possibility that the
UARTBAUD register value is zero is very low, but we had better to deal
with the "bad data" of hardware in advance to avoid division or modulo
by zero leading to undefined kernel behavior.

Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20210427021226.27468-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/serial/fsl_lpuart.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index 5b6093dc3ff2..a4c1797e30d7 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1766,6 +1766,9 @@ lpuart32_console_get_options(struct lpuart_port *sport, int *baud,
 
 	bd = lpuart32_read(sport->port.membase + UARTBAUD);
 	bd &= UARTBAUD_SBR_MASK;
+	if (!bd)
+		return;
+
 	sbr = bd;
 	uartclk = clk_get_rate(sport->clk);
 	/*
-- 
2.30.2

[PATCH AUTOSEL 4.9 06/26] tty: serial: 8250: serial_cs: Fix a memory leak in error handling path

[Sasha Levin]

From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

[ Upstream commit fad92b11047a748c996ebd6cfb164a63814eeb2e ]

In the probe function, if the final 'serial_config()' fails, 'info' is
leaking.

Add a resource handling path to free this memory.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/dc25f96b7faebf42e60fe8d02963c941cf4d8124.1621971720.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/tty/serial/8250/serial_cs.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/8250/serial_cs.c b/drivers/tty/serial/8250/serial_cs.c
index 8106353ce7aa..38e8045a36cc 100644
--- a/drivers/tty/serial/8250/serial_cs.c
+++ b/drivers/tty/serial/8250/serial_cs.c
@@ -305,6 +305,7 @@ static int serial_resume(struct pcmcia_device *link)
 static int serial_probe(struct pcmcia_device *link)
 {
 	struct serial_info *info;
+	int ret;
 
 	dev_dbg(&link->dev, "serial_attach()\n");
 
@@ -319,7 +320,15 @@ static int serial_probe(struct pcmcia_device *link)
 	if (do_sound)
 		link->config_flags |= CONF_ENABLE_SPKR;
 
-	return serial_config(link);
+	ret = serial_config(link);
+	if (ret)
+		goto free_info;
+
+	return 0;
+
+free_info:
+	kfree(info);
+	return ret;
 }
 
 static void serial_detach(struct pcmcia_device *link)
-- 
2.30.2