Fix potential NULL pointer dereference on
'commit 4da22f1418cb ("serial: 8250_fintek: fix the mismatched IRQ mode")'
We try to fix IRQ mode mismatch issue and add the following code to
detect IRQ Level or Edge mode.
struct irq_data *irq_data = irq_get_irq_data(uart->port.irq);
bool level_mode = irqd_is_level_type(irq_data);
But *irq_data had not any check and pass to irqd_is_level_type(),
it may lead to potential NULL pointer dereference.
Also modify detecting IRQ mode when fintek chip found.
Suggested-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>
Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@xxxxxxxxx>
---
drivers/tty/serial/8250/8250_fintek.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_fintek.c b/drivers/tty/serial/8250/8250_fintek.c
index 737b4b3..9119d0c 100644
--- a/drivers/tty/serial/8250/8250_fintek.c
+++ b/drivers/tty/serial/8250/8250_fintek.c
@@ -212,8 +212,8 @@ int fintek_8250_probe(struct uart_8250_port *uart)
{
struct fintek_8250 *pdata;
struct fintek_8250 probe_data;
- struct irq_data *irq_data = irq_get_irq_data(uart->port.irq);
- bool level_mode = irqd_is_level_type(irq_data);
+ struct irq_data *irq_data;
+ bool level_mode = false; /* Default to Edge/High */
if (find_base_port(&probe_data, uart->port.iobase))
return -ENODEV;
@@ -226,5 +226,14 @@ int fintek_8250_probe(struct uart_8250_port *uart)
uart->port.rs485_config = fintek_8250_rs485_config;
uart->port.private_data = pdata;
+ irq_data = irq_get_irq_data(uart->port.irq);
+ if (irq_data) {
+ level_mode = irqd_is_level_type(irq_data);
+ } else {
+ dev_warn(uart->port.dev,
+ "%s: Can't get irq_data, set this port to Edge/High",
+ __func__);
+ }
+
return fintek_8250_set_irq_mode(pdata, level_mode);
}
--
1.9.1
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